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</div> <div class="control"> <button class="button is-small is-link">Go</button> </div> </div> </form> </div> </div> <nav class="pagination is-small is-centered breathe-horizontal" role="navigation" aria-label="pagination"> <a href="" class="pagination-previous is-invisible">Previous </a> <a href="/search/?searchtype=author&query=Bostroem%2C+K+A&start=50" class="pagination-next" >Next </a> <ul class="pagination-list"> <li> <a href="/search/?searchtype=author&query=Bostroem%2C+K+A&start=0" class="pagination-link is-current" aria-label="Goto page 1">1 </a> </li> <li> <a href="/search/?searchtype=author&query=Bostroem%2C+K+A&start=50" class="pagination-link " aria-label="Page 2" aria-current="page">2 </a> </li> </ul> </nav> <ol class="breathe-horizontal" start="1"> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2411.02497">arXiv:2411.02497</a> <span> [<a href="https://arxiv.org/pdf/2411.02497">pdf</a>, <a href="https://arxiv.org/format/2411.02497">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="High Energy Astrophysical Phenomena">astro-ph.HE</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> </div> </div> <p class="title is-5 mathjax"> Asymmetries and Circumstellar Interaction in the Type II SN 2024bch </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Andrews%2C+J+E">Jennifer E. Andrews</a>, <a href="/search/astro-ph?searchtype=author&query=Shrestha%2C+M">Manisha Shrestha</a>, <a href="/search/astro-ph?searchtype=author&query=Bostroem%2C+K+A">K. Azalee Bostroem</a>, <a href="/search/astro-ph?searchtype=author&query=Dong%2C+Y">Yize Dong</a>, <a href="/search/astro-ph?searchtype=author&query=Pearson%2C+J">Jeniveve Pearson</a>, <a href="/search/astro-ph?searchtype=author&query=Fausnaugh%2C+M+M">M. M. Fausnaugh</a>, <a href="/search/astro-ph?searchtype=author&query=Sand%2C+D+J">David J. Sand</a>, <a href="/search/astro-ph?searchtype=author&query=Valenti%2C+S">S. Valenti</a>, <a href="/search/astro-ph?searchtype=author&query=Ravi%2C+A+P">Aravind P. Ravi</a>, <a href="/search/astro-ph?searchtype=author&query=Hoang%2C+E">Emily Hoang</a>, <a href="/search/astro-ph?searchtype=author&query=Hosseinzadeh%2C+G">Griffin Hosseinzadeh</a>, <a href="/search/astro-ph?searchtype=author&query=Ilyin%2C+I">Ilya Ilyin</a>, <a href="/search/astro-ph?searchtype=author&query=Janzen%2C+D">Daryl Janzen</a>, <a href="/search/astro-ph?searchtype=author&query=Lundquist%2C+M+J">M. J. Lundquist</a>, <a href="/search/astro-ph?searchtype=author&query=Meza%2C+N">Nicolaz Meza</a>, <a href="/search/astro-ph?searchtype=author&query=Smith%2C+N">Nathan Smith</a>, <a href="/search/astro-ph?searchtype=author&query=Jha%2C+S+W">Saurabh W. Jha</a>, <a href="/search/astro-ph?searchtype=author&query=Andrews%2C+M">Moira Andrews</a>, <a href="/search/astro-ph?searchtype=author&query=Farah%2C+J">Joseph Farah</a>, <a href="/search/astro-ph?searchtype=author&query=Gonzalez%2C+E+P">Estefania Padilla Gonzalez</a>, <a href="/search/astro-ph?searchtype=author&query=Howell%2C+D+A">D. Andrew Howell</a>, <a href="/search/astro-ph?searchtype=author&query=McCully%2C+C">Curtis McCully</a>, <a href="/search/astro-ph?searchtype=author&query=Newsome%2C+M">Megan Newsome</a>, <a href="/search/astro-ph?searchtype=author&query=Pellegrino%2C+C">Craig Pellegrino</a>, <a href="/search/astro-ph?searchtype=author&query=Terreran%2C+G">Giacomo Terreran</a> , et al. (6 additional authors not shown) </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2411.02497v1-abstract-short" style="display: inline;"> We present a comprehensive multi-epoch photometric and spectroscopic study of SN 2024bch, a nearby (19.9 Mpc) Type II supernova (SN) with prominent early high ionization emission lines. Optical spectra from 2.9 days after the estimated explosion reveal narrow lines of H I, He II, C IV, and N IV that disappear by day 6. High cadence photometry from the ground and TESS show that the SN brightened qu… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2411.02497v1-abstract-full').style.display = 'inline'; document.getElementById('2411.02497v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2411.02497v1-abstract-full" style="display: none;"> We present a comprehensive multi-epoch photometric and spectroscopic study of SN 2024bch, a nearby (19.9 Mpc) Type II supernova (SN) with prominent early high ionization emission lines. Optical spectra from 2.9 days after the estimated explosion reveal narrow lines of H I, He II, C IV, and N IV that disappear by day 6. High cadence photometry from the ground and TESS show that the SN brightened quickly and reached a peak M$_V \sim$ $-$17.8 mag within a week of explosion, and late-time photometry suggests a $^{56}$Ni mass of 0.050 M$_{\odot}$. High-resolution spectra from day 8 and 43 trace the unshocked circumstellar medium (CSM) and indicate a wind velocity of 30--40 km s$^{-1}$, a value consistent with a red supergiant (RSG) progenitor. Comparisons between models and the early spectra suggest a pre-SN mass-loss rate of $\dot{M} \sim 10^{-3}-10^{-2}\ M_\odot\ \mathrm{yr}^{-1}$, which is too high to be explained by quiescent mass loss from RSGs, but is consistent with some recent measurements of similar SNe. Persistent blueshifted H I and [O I] emission lines seen in the optical and NIR spectra could be produced by asymmetries in the SN ejecta, while the multi-component H$伪$ may indicate continued interaction with an asymmetric CSM well into the nebular phase. SN 2024bch provides another clue to the complex environments and mass-loss histories around massive stars. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2411.02497v1-abstract-full').style.display = 'none'; document.getElementById('2411.02497v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 4 November, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> November 2024. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">Submitted to ApJ</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2411.02493">arXiv:2411.02493</a> <span> [<a href="https://arxiv.org/pdf/2411.02493">pdf</a>, <a href="https://arxiv.org/format/2411.02493">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="High Energy Astrophysical Phenomena">astro-ph.HE</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> </div> </div> <p class="title is-5 mathjax"> Luminous Type II Short-Plateau SN 2023ufx: Asymmetric Explosion of a Partially-Stripped Massive Progenitor </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Ravi%2C+A+P">Aravind P. Ravi</a>, <a href="/search/astro-ph?searchtype=author&query=Valenti%2C+S">Stefano Valenti</a>, <a href="/search/astro-ph?searchtype=author&query=Dong%2C+Y">Yize Dong</a>, <a href="/search/astro-ph?searchtype=author&query=Hiramatsu%2C+D">Daichi Hiramatsu</a>, <a href="/search/astro-ph?searchtype=author&query=Barmentloo%2C+S">Stan Barmentloo</a>, <a href="/search/astro-ph?searchtype=author&query=Jerkstrand%2C+A">Anders Jerkstrand</a>, <a href="/search/astro-ph?searchtype=author&query=Bostroem%2C+K+A">K. Azalee Bostroem</a>, <a href="/search/astro-ph?searchtype=author&query=Pearson%2C+J">Jeniveve Pearson</a>, <a href="/search/astro-ph?searchtype=author&query=Shrestha%2C+M">Manisha Shrestha</a>, <a href="/search/astro-ph?searchtype=author&query=Andrews%2C+J+E">Jennifer E. Andrews</a>, <a href="/search/astro-ph?searchtype=author&query=Sand%2C+D+J">David J. Sand</a>, <a href="/search/astro-ph?searchtype=author&query=Hosseinzadeh%2C+G">Griffin Hosseinzadeh</a>, <a href="/search/astro-ph?searchtype=author&query=Lundquist%2C+M">Michael Lundquist</a>, <a href="/search/astro-ph?searchtype=author&query=Hoang%2C+E">Emily Hoang</a>, <a href="/search/astro-ph?searchtype=author&query=Mehta%2C+D">Darshana Mehta</a>, <a href="/search/astro-ph?searchtype=author&query=Retamal%2C+N+M">Nicolas Meza Retamal</a>, <a href="/search/astro-ph?searchtype=author&query=Martas%2C+A">Aidan Martas</a>, <a href="/search/astro-ph?searchtype=author&query=Jha%2C+S+W">Saurabh W. Jha</a>, <a href="/search/astro-ph?searchtype=author&query=Janzen%2C+D">Daryl Janzen</a>, <a href="/search/astro-ph?searchtype=author&query=Subrayan%2C+B">Bhagya Subrayan</a>, <a href="/search/astro-ph?searchtype=author&query=Howell%2C+D+A">D. Andrew Howell</a>, <a href="/search/astro-ph?searchtype=author&query=McCully%2C+C">Curtis McCully</a>, <a href="/search/astro-ph?searchtype=author&query=Farah%2C+J">Joseph Farah</a>, <a href="/search/astro-ph?searchtype=author&query=Newsome%2C+M">Megan Newsome</a>, <a href="/search/astro-ph?searchtype=author&query=Gonzalez%2C+E+P">Estefania Padilla Gonzalez</a> , et al. (12 additional authors not shown) </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2411.02493v1-abstract-short" style="display: inline;"> We present supernova (SN) 2023ufx, a unique Type IIP SN with the shortest known plateau duration ($t_\mathrm{PT}$ $\sim$47 days), a luminous V-band peak ($M_{V}$ = $-$18.42 $\pm$ 0.08 mag), and a rapid early decline rate ($s1$ = 3.47 $\pm$ 0.09 mag (50 days)$^{-1}$). By comparing observed photometry to a hydrodynamic MESA+STELLA model grid, we constrain the progenitor to be a massive red supergian… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2411.02493v1-abstract-full').style.display = 'inline'; document.getElementById('2411.02493v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2411.02493v1-abstract-full" style="display: none;"> We present supernova (SN) 2023ufx, a unique Type IIP SN with the shortest known plateau duration ($t_\mathrm{PT}$ $\sim$47 days), a luminous V-band peak ($M_{V}$ = $-$18.42 $\pm$ 0.08 mag), and a rapid early decline rate ($s1$ = 3.47 $\pm$ 0.09 mag (50 days)$^{-1}$). By comparing observed photometry to a hydrodynamic MESA+STELLA model grid, we constrain the progenitor to be a massive red supergiant with M$_\mathrm{ZAMS}$ $\simeq$19 - 25 M$_{\odot}$. Independent comparisons with nebular spectral models also suggest an initial He-core mass of $\sim$6 M$_{\odot}$, and thus a massive progenitor. For a Type IIP, SN 2023ufx produced an unusually high amount of nickel ($^{56}$Ni) $\sim$0.14 $\pm$ 0.02 M$_{\odot}$, during the explosion. We find that the short plateau duration in SN 2023ufx can be explained with the presence of a small hydrogen envelope (M$_\mathrm{H_\mathrm{env}}$ $\simeq$1.2 M$_{\odot}$), suggesting partial stripping of the progenitor. About $\simeq$0.09 M$_{\odot}$ of CSM through mass loss from late-time stellar evolution of the progenitor is needed to fit the early time ($\lesssim$10 days) pseudo-bolometric light curve. Nebular line diagnostics of broad and multi-peak components of [O I] $位位$6300, 6364, H$伪$, and [Ca II] $位位$7291, 7323 suggest that the explosion of SN 2023ufx could be inherently asymmetric, preferentially ejecting material along our line-of-sight. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2411.02493v1-abstract-full').style.display = 'none'; document.getElementById('2411.02493v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 4 November, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> November 2024. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">Submitted to ApJ, 30 pages, 19 figures</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2410.08199">arXiv:2410.08199</a> <span> [<a href="https://arxiv.org/pdf/2410.08199">pdf</a>, <a href="https://arxiv.org/format/2410.08199">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="High Energy Astrophysical Phenomena">astro-ph.HE</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> </div> </div> <p class="title is-5 mathjax"> Spectropolarimetry of SN 2023ixf reveals both circumstellar material and helium core to be aspherical </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Shrestha%2C+M">Manisha Shrestha</a>, <a href="/search/astro-ph?searchtype=author&query=DeSoto%2C+S">Sabrina DeSoto</a>, <a href="/search/astro-ph?searchtype=author&query=Sand%2C+D+J">David J. Sand</a>, <a href="/search/astro-ph?searchtype=author&query=Williams%2C+G+G">G. Grant Williams</a>, <a href="/search/astro-ph?searchtype=author&query=Hoffman%2C+J+L">Jennifer L. Hoffman</a>, <a href="/search/astro-ph?searchtype=author&query=Smith%2C+N">Nathan Smith</a>, <a href="/search/astro-ph?searchtype=author&query=Smith%2C+P+S">Paul S. Smith</a>, <a href="/search/astro-ph?searchtype=author&query=Milne%2C+P">Peter Milne</a>, <a href="/search/astro-ph?searchtype=author&query=McCall%2C+C">Callum McCall</a>, <a href="/search/astro-ph?searchtype=author&query=Maund%2C+J+R">Justyn R. Maund</a>, <a href="/search/astro-ph?searchtype=author&query=Steele%2C+I+A">Iain A Steele</a>, <a href="/search/astro-ph?searchtype=author&query=Wiersema%2C+K">Klaas Wiersema</a>, <a href="/search/astro-ph?searchtype=author&query=Andrews%2C+J+E">Jennifer E. Andrews</a>, <a href="/search/astro-ph?searchtype=author&query=Bilinski%2C+C">Christopher Bilinski</a>, <a href="/search/astro-ph?searchtype=author&query=Anche%2C+R+M">Ramya M. Anche</a>, <a href="/search/astro-ph?searchtype=author&query=Bostroem%2C+K+A">K. Azalee Bostroem</a>, <a href="/search/astro-ph?searchtype=author&query=Hosseinzadeh%2C+G">Griffin Hosseinzadeh</a>, <a href="/search/astro-ph?searchtype=author&query=Pearson%2C+J">Jeniveve Pearson</a>, <a href="/search/astro-ph?searchtype=author&query=Leonard%2C+D+C">Douglas C. Leonard</a>, <a href="/search/astro-ph?searchtype=author&query=Hsu%2C+B">Brian Hsu</a>, <a href="/search/astro-ph?searchtype=author&query=Dong%2C+Y">Yize Dong</a>, <a href="/search/astro-ph?searchtype=author&query=Hoang%2C+E">Emily Hoang</a>, <a href="/search/astro-ph?searchtype=author&query=Janzen%2C+D">Daryl Janzen</a>, <a href="/search/astro-ph?searchtype=author&query=Jencson%2C+J+E">Jacob E. Jencson</a>, <a href="/search/astro-ph?searchtype=author&query=Jha%2C+S+W">Saurabh W. Jha</a> , et al. (11 additional authors not shown) </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2410.08199v1-abstract-short" style="display: inline;"> We present multi-epoch optical spectropolarimetric and imaging polarimetric observations of the nearby Type II supernova (SN) 2023ixf discovered in M101 at a distance of 6.85 Mpc. The first imaging polarimetric observations were taken +2.33 days (60085.08 MJD) after the explosion, while the last imaging polarimetric data points (+73.19 and +76.19 days) were acquired after the fall from the light c… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2410.08199v1-abstract-full').style.display = 'inline'; document.getElementById('2410.08199v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2410.08199v1-abstract-full" style="display: none;"> We present multi-epoch optical spectropolarimetric and imaging polarimetric observations of the nearby Type II supernova (SN) 2023ixf discovered in M101 at a distance of 6.85 Mpc. The first imaging polarimetric observations were taken +2.33 days (60085.08 MJD) after the explosion, while the last imaging polarimetric data points (+73.19 and +76.19 days) were acquired after the fall from the light curve plateau. At +2.33 days there is strong evidence of circumstellar material (CSM) interaction in the spectra and the light curve. A significant level of polarization $P_r = 0.88\pm 0.06 \% $ seen during this phase indicates that this CSM is aspherical. We find that the polarization evolves with time toward the interstellar polarization level ($0.35\%$) during the photospheric phase, which suggests that the recombination photosphere is spherically symmetric. There is a jump in polarization ($P_r =0.65 \pm 0.08 \% $) at +73.19 days when the light curve falls from the plateau. This is a phase where polarimetric data is sensitive to non-spherical inner ejecta or a decrease in optical depth into the single scattering regime. We also present spectropolarimetric data that reveal line (de)polarization during most of the observed epochs. In addition, at +14.50 days we see an "inverse P Cygn" profile in the H and He line polarization, which clearly indicates the presence of asymmetrically distributed material overlying the photosphere. The overall temporal evolution of polarization is typical for Type II SNe, but the high level of polarization during the rising phase has only been observed in SN 2023ixf. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2410.08199v1-abstract-full').style.display = 'none'; document.getElementById('2410.08199v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 10 October, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> October 2024. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">14 pages, 7 figures, submitted to ApJL, comments welcome</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2409.02666">arXiv:2409.02666</a> <span> [<a href="https://arxiv.org/pdf/2409.02666">pdf</a>, <a href="https://arxiv.org/format/2409.02666">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="High Energy Astrophysical Phenomena">astro-ph.HE</span> </div> </div> <p class="title is-5 mathjax"> SN 2021foa: Deriving a continuity between SN IIn and SN Ibn </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Gangopadhyay%2C+A">Anjasha Gangopadhyay</a>, <a href="/search/astro-ph?searchtype=author&query=Dukiya%2C+N">Naveen Dukiya</a>, <a href="/search/astro-ph?searchtype=author&query=Moriya%2C+T+J">Takashi J Moriya</a>, <a href="/search/astro-ph?searchtype=author&query=Tanaka%2C+M">Masaomi Tanaka</a>, <a href="/search/astro-ph?searchtype=author&query=Maeda%2C+K">Keiichi Maeda</a>, <a href="/search/astro-ph?searchtype=author&query=Howell%2C+D+A">D. Andrew Howell</a>, <a href="/search/astro-ph?searchtype=author&query=Singh%2C+M">Mridweeka Singh</a>, <a href="/search/astro-ph?searchtype=author&query=Singh%2C+A">Avinash Singh</a>, <a href="/search/astro-ph?searchtype=author&query=Sollerman%2C+J">Jesper Sollerman</a>, <a href="/search/astro-ph?searchtype=author&query=Kawabata%2C+K+S">Koji S Kawabata</a>, <a href="/search/astro-ph?searchtype=author&query=Brennan%2C+S+J">Sean J Brennan</a>, <a href="/search/astro-ph?searchtype=author&query=Pellegrino%2C+C">Craig Pellegrino</a>, <a href="/search/astro-ph?searchtype=author&query=Dastidar%2C+R">Raya Dastidar</a>, <a href="/search/astro-ph?searchtype=author&query=Nakaoka%2C+T">Tatsuya Nakaoka</a>, <a href="/search/astro-ph?searchtype=author&query=Kawabata%2C+M">Miho Kawabata</a>, <a href="/search/astro-ph?searchtype=author&query=Misra%2C+K">Kuntal Misra</a>, <a href="/search/astro-ph?searchtype=author&query=Schulze%2C+S">Steve Schulze</a>, <a href="/search/astro-ph?searchtype=author&query=Chandra%2C+P">Poonam Chandra</a>, <a href="/search/astro-ph?searchtype=author&query=Taguchi%2C+K">Kenta Taguchi</a>, <a href="/search/astro-ph?searchtype=author&query=Sahu%2C+D+K">Devendra K Sahu</a>, <a href="/search/astro-ph?searchtype=author&query=McCully%2C+C">Curtis McCully</a>, <a href="/search/astro-ph?searchtype=author&query=Bostroem%2C+K+A">K. Azalee Bostroem</a>, <a href="/search/astro-ph?searchtype=author&query=Gonzalez%2C+E+P">Estefania Padilla Gonzalez</a>, <a href="/search/astro-ph?searchtype=author&query=Newsome%2C+M">Megan Newsome</a>, <a href="/search/astro-ph?searchtype=author&query=Hiramatsu%2C+D">Daichi Hiramatsu</a> , et al. (4 additional authors not shown) </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2409.02666v2-abstract-short" style="display: inline;"> We present the long-term photometric and spectroscopic analysis of a transitioning SN~IIn/Ibn from $-$10.8 d to 150.7 d post $V$-band maximum. SN~2021foa shows prominent He {\sc i} lines comparable in strength to the H$伪$ line around peak, placing SN~2021foa between the SN~IIn and SN~Ibn populations. The spectral comparison shows that it resembles the SN~IIn population at pre-maximum, becomes inte… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2409.02666v2-abstract-full').style.display = 'inline'; document.getElementById('2409.02666v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2409.02666v2-abstract-full" style="display: none;"> We present the long-term photometric and spectroscopic analysis of a transitioning SN~IIn/Ibn from $-$10.8 d to 150.7 d post $V$-band maximum. SN~2021foa shows prominent He {\sc i} lines comparable in strength to the H$伪$ line around peak, placing SN~2021foa between the SN~IIn and SN~Ibn populations. The spectral comparison shows that it resembles the SN~IIn population at pre-maximum, becomes intermediate between SNe~IIn/Ibn and at post-maximum matches with SN~IIn 1996al. The photometric evolution shows a precursor at $-$50 d and a light curve shoulder around 17d. The peak luminosity and color evolution of SN 2021foa are consistent with most SNe~IIn and Ibn in our comparison sample. SN~2021foa shows the unique case of a SN~IIn where the narrow P-Cygni in H$伪$ appear at later stages. The H$伪$ profile consists of a narrow (500 -- 1200 km s$^{-1}$) component, intermediate width (3000 -- 8000 km s$^{-1}$) and broad component in absorption. Temporal evolution of the H$伪$ profile favours a disk-like CSM geometry. Hydrodynamical modelling of the lightcurve well reproduces a two-component CSM structure with different densities ($蟻$ $\propto$ r$^{-2}$ -- $蟻$ $\propto$ r$^{-5}$), mass-loss rates (10$^{-3}$ -- 10$^{-1}$ M$_{\odot}$ yr$^{-1}$) assuming a wind velocity of 1000 km s$^{-1}$ and having a CSM mass of 0.18 M$_{\odot}$. The overall evolution indicates that SN~2021foa most likely originated from a LBV star transitioning to a WR star with the mass-loss rate increasing in the period from 5 to 0.5 years before the explosion or it could be due to a binary interaction. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2409.02666v2-abstract-full').style.display = 'none'; document.getElementById('2409.02666v2-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 8 September, 2024; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 4 September, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> September 2024. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">Submitted to MNRAS; 20 pages, 16 figures, 4 tables</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2408.11928">arXiv:2408.11928</a> <span> [<a href="https://arxiv.org/pdf/2408.11928">pdf</a>, <a href="https://arxiv.org/format/2408.11928">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="High Energy Astrophysical Phenomena">astro-ph.HE</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> </div> </div> <p class="title is-5 mathjax"> Ejecta masses in Type Ia Supernovae -- Implications for the Progenitor and the Explosion Scenario </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Bora%2C+Z">Zs贸fia Bora</a>, <a href="/search/astro-ph?searchtype=author&query=K%C3%B6nyves-T%C3%B3th%2C+R">R茅ka K枚nyves-T贸th</a>, <a href="/search/astro-ph?searchtype=author&query=Vink%C3%B3%2C+J">J贸zsef Vink贸</a>, <a href="/search/astro-ph?searchtype=author&query=B%C3%A1nhidi%2C+D">Dominik B谩nhidi</a>, <a href="/search/astro-ph?searchtype=author&query=B%C3%ADr%C3%B3%2C+I+B">Imre Barna B铆r贸</a>, <a href="/search/astro-ph?searchtype=author&query=Bostroem%2C+K+A">K. Azalee Bostroem</a>, <a href="/search/astro-ph?searchtype=author&query=B%C3%B3di%2C+A">Attila B贸di</a>, <a href="/search/astro-ph?searchtype=author&query=Burke%2C+J">Jamison Burke</a>, <a href="/search/astro-ph?searchtype=author&query=Cs%C3%A1nyi%2C+I">Istv谩n Cs谩nyi</a>, <a href="/search/astro-ph?searchtype=author&query=Cseh%2C+B">Borb谩la Cseh</a>, <a href="/search/astro-ph?searchtype=author&query=Farah%2C+J">Joseph Farah</a>, <a href="/search/astro-ph?searchtype=author&query=Filippenko%2C+A+V">Alexei V. Filippenko</a>, <a href="/search/astro-ph?searchtype=author&query=Heged%C5%B1s%2C+T">Tibor Heged疟s</a>, <a href="/search/astro-ph?searchtype=author&query=Hiramatsu%2C+D">Daichi Hiramatsu</a>, <a href="/search/astro-ph?searchtype=author&query=Horti-D%C3%A1vid%2C+%C3%81">脕goston Horti-D谩vid</a>, <a href="/search/astro-ph?searchtype=author&query=Howell%2C+D+A">D. Andrew Howell</a>, <a href="/search/astro-ph?searchtype=author&query=Jha%2C+S+W">Saurabh W. Jha</a>, <a href="/search/astro-ph?searchtype=author&query=Kalup%2C+C">Csilla Kalup</a>, <a href="/search/astro-ph?searchtype=author&query=Krezinger%2C+M">M谩t茅 Krezinger</a>, <a href="/search/astro-ph?searchtype=author&query=Kriskovics%2C+L">Levente Kriskovics</a>, <a href="/search/astro-ph?searchtype=author&query=McCully%2C+C">Curtis McCully</a>, <a href="/search/astro-ph?searchtype=author&query=Newsome%2C+M">Megan Newsome</a>, <a href="/search/astro-ph?searchtype=author&query=Ordasi%2C+A">Andr谩s Ordasi</a>, <a href="/search/astro-ph?searchtype=author&query=Gonzalez%2C+E+P">Estefania Padilla Gonzalez</a>, <a href="/search/astro-ph?searchtype=author&query=P%C3%A1l%2C+A">Andr谩s P谩l</a> , et al. (13 additional authors not shown) </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2408.11928v2-abstract-short" style="display: inline;"> The progenitor system(s) as well as the explosion mechanism(s) of thermonuclear (Type Ia) supernovae are long-standing issues in astrophysics. Here we present ejecta masses and other physical parameters for 28 recent Type Ia supernovae inferred from multiband photometric and optical spectroscopic data. Our results confirm that the majority of SNe Ia show {\it observable} ejecta masses below the Ch… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2408.11928v2-abstract-full').style.display = 'inline'; document.getElementById('2408.11928v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2408.11928v2-abstract-full" style="display: none;"> The progenitor system(s) as well as the explosion mechanism(s) of thermonuclear (Type Ia) supernovae are long-standing issues in astrophysics. Here we present ejecta masses and other physical parameters for 28 recent Type Ia supernovae inferred from multiband photometric and optical spectroscopic data. Our results confirm that the majority of SNe Ia show {\it observable} ejecta masses below the Chandrasekhar-limit (having a mean $M_{\rm ej} \approx 1.1 \pm 0.3$ M$_\odot$), consistent with the predictions of recent sub-M$_{\rm Ch}$ explosion models. They are compatible with models assuming either single- or double-degenerate progenitor configurations. We also recover a sub-sample of supernovae within $1.2 $ M$_\odot$ $< M_{\rm {ej}} < 1.5$ M$_\odot$ that are consistent with near-Chandrasekhar explosions. Taking into account the uncertainties of the inferred ejecta masses, about half of our SNe are compatible with both explosion models. We compare our results with those in previous studies, and discuss the caveats and concerns regarding the applied methodology. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2408.11928v2-abstract-full').style.display = 'none'; document.getElementById('2408.11928v2-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 23 August, 2024; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 21 August, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> August 2024. </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2408.07874">arXiv:2408.07874</a> <span> [<a href="https://arxiv.org/pdf/2408.07874">pdf</a>, <a href="https://arxiv.org/format/2408.07874">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="High Energy Astrophysical Phenomena">astro-ph.HE</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> </div> </div> <p class="title is-5 mathjax"> One Year of SN 2023ixf: Breaking Through the Degenerate Parameter Space in Light-Curve Models with Pulsating Progenitors </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Hsu%2C+B">Brian Hsu</a>, <a href="/search/astro-ph?searchtype=author&query=Smith%2C+N">Nathan Smith</a>, <a href="/search/astro-ph?searchtype=author&query=Goldberg%2C+J+A">Jared A. Goldberg</a>, <a href="/search/astro-ph?searchtype=author&query=Bostroem%2C+K+A">K. Azalee Bostroem</a>, <a href="/search/astro-ph?searchtype=author&query=Hosseinzadeh%2C+G">Griffin Hosseinzadeh</a>, <a href="/search/astro-ph?searchtype=author&query=Sand%2C+D+J">David J. Sand</a>, <a href="/search/astro-ph?searchtype=author&query=Pearson%2C+J">Jeniveve Pearson</a>, <a href="/search/astro-ph?searchtype=author&query=Hiramatsu%2C+D">Daichi Hiramatsu</a>, <a href="/search/astro-ph?searchtype=author&query=Andrews%2C+J+E">Jennifer E. Andrews</a>, <a href="/search/astro-ph?searchtype=author&query=Beasor%2C+E+R">Emma R. Beasor</a>, <a href="/search/astro-ph?searchtype=author&query=Dong%2C+Y">Yize Dong</a>, <a href="/search/astro-ph?searchtype=author&query=Farah%2C+J">Joseph Farah</a>, <a href="/search/astro-ph?searchtype=author&query=Galbany%2C+L">Llu脥s Galbany</a>, <a href="/search/astro-ph?searchtype=author&query=Gomez%2C+S">Sebastian Gomez</a>, <a href="/search/astro-ph?searchtype=author&query=Gonzalez%2C+E+P">Estefania Padilla Gonzalez</a>, <a href="/search/astro-ph?searchtype=author&query=Guti%C3%A9rrez%2C+C+P">Claudia P. Guti茅rrez</a>, <a href="/search/astro-ph?searchtype=author&query=Howell%2C+D+A">D. Andrew Howell</a>, <a href="/search/astro-ph?searchtype=author&query=K%C3%B6nyves-T%C3%B3th%2C+R">R茅ka K枚nyves-T贸th</a>, <a href="/search/astro-ph?searchtype=author&query=McCully%2C+C">Curtis McCully</a>, <a href="/search/astro-ph?searchtype=author&query=Newsome%2C+M">Megan Newsome</a>, <a href="/search/astro-ph?searchtype=author&query=Shrestha%2C+M">Manisha Shrestha</a>, <a href="/search/astro-ph?searchtype=author&query=Terreran%2C+G">Giacomo Terreran</a>, <a href="/search/astro-ph?searchtype=author&query=Villar%2C+V+A">V. Ashley Villar</a>, <a href="/search/astro-ph?searchtype=author&query=Wang%2C+X">Xiaofeng Wang</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2408.07874v1-abstract-short" style="display: inline;"> We present and analyze the extensive optical broadband photometry of the Type II SN 2023ixf up to one year after explosion. We find that, when compared to two pre-existing model grids, the pseudo-bolometric light curve is consistent with drastically different combinations of progenitor and explosion properties. This may be an effect of known degeneracies in Type IIP light-curve models. We independ… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2408.07874v1-abstract-full').style.display = 'inline'; document.getElementById('2408.07874v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2408.07874v1-abstract-full" style="display: none;"> We present and analyze the extensive optical broadband photometry of the Type II SN 2023ixf up to one year after explosion. We find that, when compared to two pre-existing model grids, the pseudo-bolometric light curve is consistent with drastically different combinations of progenitor and explosion properties. This may be an effect of known degeneracies in Type IIP light-curve models. We independently compute a large grid of ${\tt MESA+STELLA}$ single-star progenitor and light-curve models with various zero-age main-sequence masses, mass-loss efficiencies, and convective efficiencies. Using the observed progenitor variability as an additional constraint, we select stellar models consistent with the pulsation period and explode them according to previously established scaling laws to match plateau properties. Our hydrodynamic modeling indicates that SN 2023ixf is most consistent with a moderate-energy ($E_{\rm exp}\approx7\times10^{50}$ erg) explosion of an initially high-mass red supergiant progenitor ($\gtrsim 17\ M_{\odot}$) that lost a significant amount of mass in its prior evolution, leaving a low-mass hydrogen envelope ($\lesssim 3\ M_{\odot}$) at the time of explosion, with a radius $\gtrsim 950\ R_{\odot}$ and a synthesized $^{56}$Ni mass of $0.07\ M_{\odot}$. We posit that previous mass transfer in a binary system may have stripped the envelope of SN 2023ixf's progenitor. The analysis method with pulsation period presented in this work offers a way to break degeneracies in light-curve modeling in the future, particularly with the upcoming Vera C.~Rubin Observatory Legacy Survey of Space and Time, when a record of progenitor variability will be more common. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2408.07874v1-abstract-full').style.display = 'none'; document.getElementById('2408.07874v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 14 August, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> August 2024. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">18 pages, 7 figures, submitted to ApJ. Comments welcome</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2408.03993">arXiv:2408.03993</a> <span> [<a href="https://arxiv.org/pdf/2408.03993">pdf</a>, <a href="https://arxiv.org/format/2408.03993">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="High Energy Astrophysical Phenomena">astro-ph.HE</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> </div> </div> <p class="title is-5 mathjax"> Circumstellar Interaction in the Ultraviolet Spectra of SN 2023ixf 14-66 Days After Explosion </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Bostroem%2C+K+A">K. Azalee Bostroem</a>, <a href="/search/astro-ph?searchtype=author&query=Sand%2C+D+J">David J. Sand</a>, <a href="/search/astro-ph?searchtype=author&query=Dessart%2C+L">Luc Dessart</a>, <a href="/search/astro-ph?searchtype=author&query=Smith%2C+N">Nathan Smith</a>, <a href="/search/astro-ph?searchtype=author&query=Jha%2C+S+W">Saurabh W. Jha</a>, <a href="/search/astro-ph?searchtype=author&query=Valenti%2C+S">Stefano Valenti</a>, <a href="/search/astro-ph?searchtype=author&query=Andrews%2C+J+E">Jennifer E. Andrews</a>, <a href="/search/astro-ph?searchtype=author&query=Dong%2C+Y">Yize Dong</a>, <a href="/search/astro-ph?searchtype=author&query=Filippenko%2C+A+V">Alexei V. Filippenko</a>, <a href="/search/astro-ph?searchtype=author&query=Gomez%2C+S">Sebastian Gomez</a>, <a href="/search/astro-ph?searchtype=author&query=Hiramatsu%2C+D">Daichi Hiramatsu</a>, <a href="/search/astro-ph?searchtype=author&query=Hoang%2C+E+T">Emily T. Hoang</a>, <a href="/search/astro-ph?searchtype=author&query=Hosseinzadeh%2C+G">Griffin Hosseinzadeh</a>, <a href="/search/astro-ph?searchtype=author&query=Howell%2C+D+A">D. Andrew Howell</a>, <a href="/search/astro-ph?searchtype=author&query=Jencson%2C+J+E">Jacob E. Jencson</a>, <a href="/search/astro-ph?searchtype=author&query=Lundquist%2C+M">Michael Lundquist</a>, <a href="/search/astro-ph?searchtype=author&query=McCully%2C+C">Curtis McCully</a>, <a href="/search/astro-ph?searchtype=author&query=Mehta%2C+D">Darshana Mehta</a>, <a href="/search/astro-ph?searchtype=author&query=Retamal%2C+N+E+M">Nicolas E. Meza Retamal</a>, <a href="/search/astro-ph?searchtype=author&query=Pearson%2C+J">Jeniveve Pearson</a>, <a href="/search/astro-ph?searchtype=author&query=Ravi%2C+A+P">Aravind P. Ravi</a>, <a href="/search/astro-ph?searchtype=author&query=Shrestha%2C+M">Manisha Shrestha</a>, <a href="/search/astro-ph?searchtype=author&query=Wyatt%2C+S">Samuel Wyatt</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2408.03993v2-abstract-short" style="display: inline;"> SN 2023ixf was discovered in M101 within a day of explosion and rapidly classified as a Type II supernova with flash features. Here we present ultraviolet (UV) spectra obtained with the Hubble Space Telescope 14, 19, 24, and 66 days after explosion. Interaction between the supernova ejecta and circumstellar material (CSM) is seen in the UV throughout our observations in the flux of the first three… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2408.03993v2-abstract-full').style.display = 'inline'; document.getElementById('2408.03993v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2408.03993v2-abstract-full" style="display: none;"> SN 2023ixf was discovered in M101 within a day of explosion and rapidly classified as a Type II supernova with flash features. Here we present ultraviolet (UV) spectra obtained with the Hubble Space Telescope 14, 19, 24, and 66 days after explosion. Interaction between the supernova ejecta and circumstellar material (CSM) is seen in the UV throughout our observations in the flux of the first three epochs and asymmetric Mg II emission on day 66. We compare our observations to CMFGEN supernova models that include CSM interaction ($\dot{M}<10^{-3}$ M$_{\odot}$ yr$^{-1}$) and find that the power from CSM interaction is decreasing with time, from $L_{\rm sh}\approx5\times10^{42}$ erg s$^{-1}$ to $L_{\rm sh}\approx1\times10^{40}$ erg s$^{-1}$ between days 14 and 66. We examine the contribution of individual atomic species to the spectra on days 14 and 19, showing that the majority of the features are dominated by iron, nickel, magnesium, and chromium absorption in the ejecta. The UV spectral energy distribution of SN 2023ixf sits between that of supernovae which show no definitive signs of CSM interaction and those with persistent signatures assuming the same progenitor radius and metallicity. Finally, we show that the evolution and asymmetric shape of the Mg II $位位$ 2796, 2802 emission are not unique to SN 2023ixf. These observations add to the early measurements of dense, confined CSM interaction, tracing the mass-loss history of SN 2023ixf to $\sim33$ yr prior to the explosion and the density profile to a radius of $\sim5.7\times10^{15}$ cm. They show the relatively short evolution from a quiescent red supergiant wind to high mass loss. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2408.03993v2-abstract-full').style.display = 'none'; document.getElementById('2408.03993v2-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 18 September, 2024; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 7 August, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> August 2024. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">Accepted ApJL</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2408.01482">arXiv:2408.01482</a> <span> [<a href="https://arxiv.org/pdf/2408.01482">pdf</a>, <a href="https://arxiv.org/format/2408.01482">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="High Energy Astrophysical Phenomena">astro-ph.HE</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Astrophysics of Galaxies">astro-ph.GA</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> </div> </div> <p class="title is-5 mathjax"> AT2023vto: An Exceptionally Luminous Helium Tidal Disruption Event from a Massive Star </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Kumar%2C+H">Harsh Kumar</a>, <a href="/search/astro-ph?searchtype=author&query=Berger%2C+E">Edo Berger</a>, <a href="/search/astro-ph?searchtype=author&query=Hiramatsu%2C+D">Daichi Hiramatsu</a>, <a href="/search/astro-ph?searchtype=author&query=Gomez%2C+S">Sebastian Gomez</a>, <a href="/search/astro-ph?searchtype=author&query=Blanchard%2C+P+K">Peter K. Blanchard</a>, <a href="/search/astro-ph?searchtype=author&query=Cendes%2C+Y">Yvette Cendes</a>, <a href="/search/astro-ph?searchtype=author&query=Bostroem%2C+K+A">K. Azalee Bostroem</a>, <a href="/search/astro-ph?searchtype=author&query=Farah%2C+J">Joseph Farah</a>, <a href="/search/astro-ph?searchtype=author&query=Gonzalez%2C+E+P">Estefania Padilla Gonzalez</a>, <a href="/search/astro-ph?searchtype=author&query=Howell%2C+A">Andrew Howell</a>, <a href="/search/astro-ph?searchtype=author&query=McCully%2C+C">Curtis McCully</a>, <a href="/search/astro-ph?searchtype=author&query=Newsome%2C+M">Megan Newsome</a>, <a href="/search/astro-ph?searchtype=author&query=Terreran%2C+G">Giacomo Terreran</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2408.01482v1-abstract-short" style="display: inline;"> We present optical/UV observations and the spectroscopic classification of the transient AT2023vto as a tidal disruption event (TDE) at z = 0.4846. The spectrum is dominated by a broad He II $位$4686 emission line, with a width of ~ $3.76 \times 10^4$ km/s and a blueshift of ~ $1.05 \times 10^4$ km/s, classifying it as a member of the TDE-He class. The light curve exhibits a long rise and decline t… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2408.01482v1-abstract-full').style.display = 'inline'; document.getElementById('2408.01482v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2408.01482v1-abstract-full" style="display: none;"> We present optical/UV observations and the spectroscopic classification of the transient AT2023vto as a tidal disruption event (TDE) at z = 0.4846. The spectrum is dominated by a broad He II $位$4686 emission line, with a width of ~ $3.76 \times 10^4$ km/s and a blueshift of ~ $1.05 \times 10^4$ km/s, classifying it as a member of the TDE-He class. The light curve exhibits a long rise and decline timescale, with a large peak absolute magnitude of M$_g$ ~ -23.6, making it the most luminous of the classical optical TDEs (H, H+He, He) discovered to date by about 2 mag (and ~ 4 mag compared to the mean of the population). The light curve exhibits a persistent blue color of g - r ~ -0.4 mag throughout its evolution, similar to other TDEs, but distinct from supernovae. We identify the host galaxy of AT2023vto in archival Pan-STARRS images and find that the transient is located at the galaxy center, and that its inferred central black hole mass is ~ $10^7~M_{\odot}$. Modeling the light curves of AT2023vto, we find that it resulted from the disruption of a ~ 9 $M_{\odot}$ star by a ~$10^7~M_{\odot}$ supermassive black hole. The star mass is about 5 times larger than the highest star masses previously inferred in TDEs, and the black hole mass is at the high end of the distribution. AT2023vto is comparable in luminosity and timescale to some putative TDEs (with a blue featureless continuum), as well as to the mean of the recently identified population of ambiguous nuclear transients (ANTs), although the latter are spectroscopically distinct and tend to have longer timescales. ANTs have been speculated to arise from tidal disruptions of massive stars, perhaps in active galactic nuclei, and AT2023vto may represent a similar case but in a dormant black hole, thereby bridging the TDE and ANT populations. We anticipate that Rubin Observatory / LSST will uncover similar luminous TDEs to z ~ 3. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2408.01482v1-abstract-full').style.display = 'none'; document.getElementById('2408.01482v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 2 August, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> August 2024. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">21 pages, 8 figures</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2407.18291">arXiv:2407.18291</a> <span> [<a href="https://arxiv.org/pdf/2407.18291">pdf</a>, <a href="https://arxiv.org/format/2407.18291">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="High Energy Astrophysical Phenomena">astro-ph.HE</span> </div> </div> <p class="title is-5 mathjax"> The X-ray Luminous Type Ibn SN 2022ablq: Estimates of Pre-explosion Mass Loss and Constraints on Precursor Emission </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Pellegrino%2C+C">C. Pellegrino</a>, <a href="/search/astro-ph?searchtype=author&query=Modjaz%2C+M">M. Modjaz</a>, <a href="/search/astro-ph?searchtype=author&query=Takei%2C+Y">Y. Takei</a>, <a href="/search/astro-ph?searchtype=author&query=Tsuna%2C+D">D. Tsuna</a>, <a href="/search/astro-ph?searchtype=author&query=Newsome%2C+M">M. Newsome</a>, <a href="/search/astro-ph?searchtype=author&query=Pritchard%2C+T">T. Pritchard</a>, <a href="/search/astro-ph?searchtype=author&query=Baer-Way%2C+R">R. Baer-Way</a>, <a href="/search/astro-ph?searchtype=author&query=Bostroem%2C+K+A">K. A. Bostroem</a>, <a href="/search/astro-ph?searchtype=author&query=Chandra%2C+P">P. Chandra</a>, <a href="/search/astro-ph?searchtype=author&query=Charalampopoulos%2C+P">P. Charalampopoulos</a>, <a href="/search/astro-ph?searchtype=author&query=Dong%2C+Y">Y. Dong</a>, <a href="/search/astro-ph?searchtype=author&query=Farah%2C+J">J. Farah</a>, <a href="/search/astro-ph?searchtype=author&query=Howell%2C+D+A">D. A. Howell</a>, <a href="/search/astro-ph?searchtype=author&query=McCully%2C+C">C. McCully</a>, <a href="/search/astro-ph?searchtype=author&query=Mohamed%2C+S">S. Mohamed</a>, <a href="/search/astro-ph?searchtype=author&query=Gonzalez%2C+E+P">E. Padilla Gonzalez</a>, <a href="/search/astro-ph?searchtype=author&query=Terreran%2C+G">G. Terreran</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2407.18291v1-abstract-short" style="display: inline;"> Type Ibn supernovae (SNe Ibn) are rare stellar explosions powered primarily by interaction between the SN ejecta and H-poor, He-rich material lost by their progenitor stars. Multi-wavelength observations, particularly in the X-rays, of SNe Ibn constrain their poorly-understood progenitor channels and mass-loss mechanisms. Here we present Swift X-ray, ultraviolet, and ground-based optical observati… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2407.18291v1-abstract-full').style.display = 'inline'; document.getElementById('2407.18291v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2407.18291v1-abstract-full" style="display: none;"> Type Ibn supernovae (SNe Ibn) are rare stellar explosions powered primarily by interaction between the SN ejecta and H-poor, He-rich material lost by their progenitor stars. Multi-wavelength observations, particularly in the X-rays, of SNe Ibn constrain their poorly-understood progenitor channels and mass-loss mechanisms. Here we present Swift X-ray, ultraviolet, and ground-based optical observations of the Type Ibn SN 2022ablq -- only the second SN Ibn with X-ray detections to date. While similar to the prototypical Type Ibn SN 2006jc in the optical, SN 2022ablq is roughly an order of magnitude more luminous in the X-rays, reaching unabsorbed luminosities $L_X$ $\sim$ 3$\times$10$^{40}$ erg s$^{-1}$ between 0.2 - 10 keV. From these X-ray observations we infer time-varying mass-loss rates between 0.05 - 0.5 $M_\odot$ yr$^{-1}$ peaking 0.5 - 2 yr before explosion. This complex mass-loss history and circumstellar environment disfavor steady-state winds as the primary progenitor mass-loss mechanism. We also search for precursor emission from alternative mass-loss mechanisms, such as eruptive outbursts, in forced photometry during the two years before explosion. We find no statistically significant detections brighter than M $\approx$ -14 -- too shallow to rule out precursor events similar to those observed for other SNe Ibn. Finally, numerical models of the explosion of a $\sim$15 $M_\odot$ helium star that undergoes an eruptive outburst $\approx$1.8 years before explosion are consistent with the observed bolometric light curve. We conclude that our observations disfavor a Wolf-Rayet star progenitor losing He-rich material via stellar winds and instead favor lower-mass progenitor models, including Roche-lobe overflow in helium stars with compact binary companions or stars that undergo eruptive outbursts during late-stage nucleosynthesis stages. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2407.18291v1-abstract-full').style.display = 'none'; document.getElementById('2407.18291v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 25 July, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> July 2024. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">23 pages, 8 figures, submitted to ApJ. Comments welcome</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2406.11972">arXiv:2406.11972</a> <span> [<a href="https://arxiv.org/pdf/2406.11972">pdf</a>, <a href="https://arxiv.org/format/2406.11972">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="High Energy Astrophysical Phenomena">astro-ph.HE</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Astrophysics of Galaxies">astro-ph.GA</span> </div> </div> <p class="title is-5 mathjax"> Mapping the Inner 0.1 pc of a Supermassive Black Hole Environment with the Tidal Disruption Event and Extreme Coronal Line Emitter AT 2022upj </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Newsome%2C+M">Megan Newsome</a>, <a href="/search/astro-ph?searchtype=author&query=Arcavi%2C+I">Iair Arcavi</a>, <a href="/search/astro-ph?searchtype=author&query=Howell%2C+D+A">D. Andrew Howell</a>, <a href="/search/astro-ph?searchtype=author&query=McCully%2C+C">Curtis McCully</a>, <a href="/search/astro-ph?searchtype=author&query=Terreran%2C+G">Giacomo Terreran</a>, <a href="/search/astro-ph?searchtype=author&query=Hosseinzadeh%2C+G">Griffin Hosseinzadeh</a>, <a href="/search/astro-ph?searchtype=author&query=Bostroem%2C+K+A">K. Azalee Bostroem</a>, <a href="/search/astro-ph?searchtype=author&query=Dgany%2C+Y">Yael Dgany</a>, <a href="/search/astro-ph?searchtype=author&query=Farah%2C+J">Joseph Farah</a>, <a href="/search/astro-ph?searchtype=author&query=Faris%2C+S">Sara Faris</a>, <a href="/search/astro-ph?searchtype=author&query=Padilla-Gonzalez%2C+E">Estefania Padilla-Gonzalez</a>, <a href="/search/astro-ph?searchtype=author&query=Pellegrino%2C+C">Craig Pellegrino</a>, <a href="/search/astro-ph?searchtype=author&query=Andrews%2C+M">Moira Andrews</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2406.11972v2-abstract-short" style="display: inline;"> Extreme coronal line emitters (ECLEs) are objects showing transient high-ionization lines in the centers of galaxies. They have been attributed to echoes of high-energy flares of ionizing radiation, such as those produced by tidal disruption events (TDEs), but have only recently been observed within hundreds of days after an optical transient was detected. AT 2022upj is a nuclear UV-optical flare… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2406.11972v2-abstract-full').style.display = 'inline'; document.getElementById('2406.11972v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2406.11972v2-abstract-full" style="display: none;"> Extreme coronal line emitters (ECLEs) are objects showing transient high-ionization lines in the centers of galaxies. They have been attributed to echoes of high-energy flares of ionizing radiation, such as those produced by tidal disruption events (TDEs), but have only recently been observed within hundreds of days after an optical transient was detected. AT 2022upj is a nuclear UV-optical flare at z=0.054 with spectra showing [Fe X] 位6375 and [Fe XIV] 位5303 during the optical peak, the earliest presence of extreme coronal lines during an ongoing transient. AT 2022upj is also the second ever ECLE (and first with a concurrent flare) to show broad He II 位4686 emission, a key signature of optical/UV TDEs. We also detect X-ray emission during the optical transient phase, which may be related to the source of ionizing photons for the extreme coronal lines. Finally, we analyze the spectroscopic evolution of each emission line and find that [Fe X] and [Fe XIV] weaken within 400d of optical peak, while [Fe VII] 位5720, [Fe VII] 位6087, and [O III] 位位4959,5007 emerge over the same period. The velocities of the iron lines indicate circumnuclear gas within 0.1pc of the central supermassive black hole (SMBH), while a dust echo inferred from NEOWISE data indicates that circumnuclear dust lies at a minimum of 0.4pc away, providing evidence of stratified material around a SMBH. AT 2022upj is the first confirmed ECLE-TDE with clear signatures of both classes. This event's spectroscopic evolution on a $\sim$year unveils the impact of highly energetic flares such as TDEs on the complex environments around SMBHs. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2406.11972v2-abstract-full').style.display = 'none'; document.getElementById('2406.11972v2-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 23 August, 2024; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 17 June, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> June 2024. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">19 pages, 17 figures. Under review by ApJ</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2405.18490">arXiv:2405.18490</a> <span> [<a href="https://arxiv.org/pdf/2405.18490">pdf</a>, <a href="https://arxiv.org/format/2405.18490">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="High Energy Astrophysical Phenomena">astro-ph.HE</span> </div> </div> <p class="title is-5 mathjax"> Extended Shock Breakout and Early Circumstellar Interaction in SN 2024ggi </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Shrestha%2C+M">Manisha Shrestha</a>, <a href="/search/astro-ph?searchtype=author&query=Bostroem%2C+K+A">K. Azalee Bostroem</a>, <a href="/search/astro-ph?searchtype=author&query=Sand%2C+D+J">David J. Sand</a>, <a href="/search/astro-ph?searchtype=author&query=Hosseinzadeh%2C+G">Griffin Hosseinzadeh</a>, <a href="/search/astro-ph?searchtype=author&query=Andrews%2C+J+E">Jennifer E. Andrews</a>, <a href="/search/astro-ph?searchtype=author&query=Dong%2C+Y">Yize Dong</a>, <a href="/search/astro-ph?searchtype=author&query=Hoang%2C+E">Emily Hoang</a>, <a href="/search/astro-ph?searchtype=author&query=Janzen%2C+D">Daryl Janzen</a>, <a href="/search/astro-ph?searchtype=author&query=Pearson%2C+J">Jeniveve Pearson</a>, <a href="/search/astro-ph?searchtype=author&query=Jencson%2C+J+E">Jacob E. Jencson</a>, <a href="/search/astro-ph?searchtype=author&query=Lundquist%2C+M+J">M. J. Lundquist</a>, <a href="/search/astro-ph?searchtype=author&query=Mehta%2C+D">Darshana Mehta</a>, <a href="/search/astro-ph?searchtype=author&query=Ravi%2C+A+P">Aravind P. Ravi</a>, <a href="/search/astro-ph?searchtype=author&query=Retamal%2C+N+M">Nicolas Meza Retamal</a>, <a href="/search/astro-ph?searchtype=author&query=Valenti%2C+S">Stefano Valenti</a>, <a href="/search/astro-ph?searchtype=author&query=Brown%2C+P+J">Peter J. Brown</a>, <a href="/search/astro-ph?searchtype=author&query=Jha%2C+S+W">Saurabh W. Jha</a>, <a href="/search/astro-ph?searchtype=author&query=Macrie%2C+C">Colin Macrie</a>, <a href="/search/astro-ph?searchtype=author&query=Hsu%2C+B">Brian Hsu</a>, <a href="/search/astro-ph?searchtype=author&query=Farah%2C+J">Joseph Farah</a>, <a href="/search/astro-ph?searchtype=author&query=Howell%2C+D+A">D. Andrew Howell</a>, <a href="/search/astro-ph?searchtype=author&query=McCully%2C+C">Curtis McCully</a>, <a href="/search/astro-ph?searchtype=author&query=Newsome%2C+M">Megan Newsome</a>, <a href="/search/astro-ph?searchtype=author&query=Gonzalez%2C+E+P">Estefania Padilla Gonzalez</a>, <a href="/search/astro-ph?searchtype=author&query=Pellegrino%2C+C">Craig Pellegrino</a> , et al. (18 additional authors not shown) </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2405.18490v2-abstract-short" style="display: inline;"> We present high-cadence photometric and spectroscopic observations of supernova (SN) 2024ggi, a Type II SN with flash spectroscopy features which exploded in the nearby galaxy NGC 3621 at $\sim$7 Mpc. The light-curve evolution over the first 30 hours can be fit by two power law indices with a break after 22 hours, rising from $M_V \approx -12.95$ mag at +0.66 days to $M_V \approx -17.91$ mag after… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2405.18490v2-abstract-full').style.display = 'inline'; document.getElementById('2405.18490v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2405.18490v2-abstract-full" style="display: none;"> We present high-cadence photometric and spectroscopic observations of supernova (SN) 2024ggi, a Type II SN with flash spectroscopy features which exploded in the nearby galaxy NGC 3621 at $\sim$7 Mpc. The light-curve evolution over the first 30 hours can be fit by two power law indices with a break after 22 hours, rising from $M_V \approx -12.95$ mag at +0.66 days to $M_V \approx -17.91$ mag after 7 days. In addition, the densely sampled color curve shows a strong blueward evolution over the first few days and then behaves as a normal SN II with a redward evolution as the ejecta cool. Such deviations could be due to interaction with circumstellar material (CSM). Early high- and low-resolution spectra clearly show high-ionization flash features from the first spectrum to +3.42 days after the explosion. From the high-resolution spectra, we calculate the CSM velocity to be 37 $\pm~4~\mathrm{km\,s^{-1}} $. We also see the line strength evolve rapidly from 1.22 to 1.49 days in the earliest high-resolution spectra. Comparison of the low-resolution spectra with CMFGEN models suggests that the pre-explosion mass-loss rate of SN 2024ggi falls in a range of $10^{-3}$ to $10^{-2}$ M$_{\odot}$ yr$^{-1}$, which is similar to that derived for SN 2023ixf. However, the rapid temporal evolution of the narrow lines in the spectra of SN 2024ggi ($R_\mathrm{CSM} \sim 2.7 \times 10^{14} \mathrm{cm}$) could indicate a smaller spatial extent of the CSM than in SN 2023ixf ($R_\mathrm{CSM} \sim 5.4 \times 10^{14} \mathrm{cm}$) which in turn implies lower total CSM mass for SN 2024ggi. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2405.18490v2-abstract-full').style.display = 'none'; document.getElementById('2405.18490v2-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 1 August, 2024; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 28 May, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> May 2024. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">23 pages, 15 figures, 4 tables, accepted for publication in ApJL</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2405.04583">arXiv:2405.04583</a> <span> [<a href="https://arxiv.org/pdf/2405.04583">pdf</a>, <a href="https://arxiv.org/format/2405.04583">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="High Energy Astrophysical Phenomena">astro-ph.HE</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> </div> </div> <p class="title is-5 mathjax"> SN2023fyq: A Type Ibn Supernova With Long-standing Precursor Activity Due to Binary Interaction </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Dong%2C+Y">Yize Dong</a>, <a href="/search/astro-ph?searchtype=author&query=Tsuna%2C+D">Daichi Tsuna</a>, <a href="/search/astro-ph?searchtype=author&query=Valenti%2C+S">Stefano Valenti</a>, <a href="/search/astro-ph?searchtype=author&query=Sand%2C+D+J">David J. Sand</a>, <a href="/search/astro-ph?searchtype=author&query=Andrews%2C+J+E">Jennifer E. Andrews</a>, <a href="/search/astro-ph?searchtype=author&query=Bostroem%2C+K+A">K. Azalee Bostroem</a>, <a href="/search/astro-ph?searchtype=author&query=Hosseinzadeh%2C+G">Griffin Hosseinzadeh</a>, <a href="/search/astro-ph?searchtype=author&query=Hoang%2C+E">Emily Hoang</a>, <a href="/search/astro-ph?searchtype=author&query=Jha%2C+S+W">Saurabh W. Jha</a>, <a href="/search/astro-ph?searchtype=author&query=Janzen%2C+D">Daryl Janzen</a>, <a href="/search/astro-ph?searchtype=author&query=Jencson%2C+J+E">Jacob E. Jencson</a>, <a href="/search/astro-ph?searchtype=author&query=Lundquist%2C+M">Michael Lundquist</a>, <a href="/search/astro-ph?searchtype=author&query=Mehta%2C+D">Darshana Mehta</a>, <a href="/search/astro-ph?searchtype=author&query=Ravi%2C+A+P">Aravind P. Ravi</a>, <a href="/search/astro-ph?searchtype=author&query=Retamal%2C+N+E+M">Nicolas E. Meza Retamal</a>, <a href="/search/astro-ph?searchtype=author&query=Pearson%2C+J">Jeniveve Pearson</a>, <a href="/search/astro-ph?searchtype=author&query=Shrestha%2C+M">Manisha Shrestha</a>, <a href="/search/astro-ph?searchtype=author&query=Bonanos%2C+A">Alceste Bonanos</a>, <a href="/search/astro-ph?searchtype=author&query=Howell%2C+D+A">D. Andrew Howell</a>, <a href="/search/astro-ph?searchtype=author&query=Smith%2C+N">Nathan Smith</a>, <a href="/search/astro-ph?searchtype=author&query=Farah%2C+J">Joseph Farah</a>, <a href="/search/astro-ph?searchtype=author&query=Hiramatsu%2C+D">Daichi Hiramatsu</a>, <a href="/search/astro-ph?searchtype=author&query=Itagaki%2C+K">Koichi Itagaki</a>, <a href="/search/astro-ph?searchtype=author&query=McCully%2C+C">Curtis McCully</a>, <a href="/search/astro-ph?searchtype=author&query=Newsome%2C+M">Megan Newsome</a> , et al. (7 additional authors not shown) </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2405.04583v2-abstract-short" style="display: inline;"> We present photometric and spectroscopic observations of SN 2023fyq, a type Ibn supernova in the nearby galaxy NGC 4388 (D$\simeq$18~Mpc). In addition, we trace long-standing precursor emission at the position of SN 2023fyq using data from DLT40, ATLAS, ZTF, ASAS-SN, Swift, and amateur astronomer Koichi Itagaki. Precursor activity is observed up to nearly three years before the supernova explosion… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2405.04583v2-abstract-full').style.display = 'inline'; document.getElementById('2405.04583v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2405.04583v2-abstract-full" style="display: none;"> We present photometric and spectroscopic observations of SN 2023fyq, a type Ibn supernova in the nearby galaxy NGC 4388 (D$\simeq$18~Mpc). In addition, we trace long-standing precursor emission at the position of SN 2023fyq using data from DLT40, ATLAS, ZTF, ASAS-SN, Swift, and amateur astronomer Koichi Itagaki. Precursor activity is observed up to nearly three years before the supernova explosion, with a relatively rapid rise in the final 100 days. The double-peaked post-explosion light curve reaches a luminosity of $\sim10^{43}~\rm erg\,s^{-1}$. The strong intermediate-width He lines observed in the nebular spectrum of SN 2023fyq imply the interaction is still active at late phases. We found that the precursor activity in SN 2023fyq is best explained by the mass transfer in a binary system involving a low-mass He star and a compact companion. An equatorial disk is likely formed in this process ($\sim$0.6$\rm M_{\odot}$), and the interaction of SN ejecta with this disk powers the main peak of the supernova. The early SN light curve reveals the presence of dense extended material ($\sim$0.3$\rm M_{\odot}$) at $\sim$3000$\rm R_{\odot}$ ejected weeks before the SN explosion, likely due to final-stage core silicon burning or runaway mass transfer resulting from binary orbital shrinking, leading to rapid rising precursor emission within $\sim$30 days prior to explosion. The final explosion could be triggered either by the core-collapse of the He star or by the merger of the He star with a compact object. SN 2023fyq, along with SN 2018gjx and SN 2015G, forms a unique class of Type Ibn SNe which originate in binary systems and are likely to exhibit detectable long-lasting pre-explosion outbursts with magnitudes ranging from $-$10 to $-$13. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2405.04583v2-abstract-full').style.display = 'none'; document.getElementById('2405.04583v2-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 19 September, 2024; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 7 May, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> May 2024. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">submitted to ApJ</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2404.17043">arXiv:2404.17043</a> <span> [<a href="https://arxiv.org/pdf/2404.17043">pdf</a>, <a href="https://arxiv.org/format/2404.17043">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="High Energy Astrophysical Phenomena">astro-ph.HE</span> </div> </div> <p class="title is-5 mathjax"> A JWST Medium Resolution MIRI Spectrum and Models of the Type Ia supernova 2021aefx at +415 d </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Ashall%2C+C">C. Ashall</a>, <a href="/search/astro-ph?searchtype=author&query=Hoeflich%2C+P">P. Hoeflich</a>, <a href="/search/astro-ph?searchtype=author&query=Baron%2C+E">E. Baron</a>, <a href="/search/astro-ph?searchtype=author&query=Shahbandeh%2C+M">M. Shahbandeh</a>, <a href="/search/astro-ph?searchtype=author&query=DerKacy%2C+J+M">J. M. DerKacy</a>, <a href="/search/astro-ph?searchtype=author&query=Medler%2C+K">K. Medler</a>, <a href="/search/astro-ph?searchtype=author&query=Shappee%2C+B+J">B. J. Shappee</a>, <a href="/search/astro-ph?searchtype=author&query=Tucker%2C+M+A">M. A. Tucker</a>, <a href="/search/astro-ph?searchtype=author&query=Fereidouni%2C+E">E. Fereidouni</a>, <a href="/search/astro-ph?searchtype=author&query=Mera%2C+T">T. Mera</a>, <a href="/search/astro-ph?searchtype=author&query=Andrews%2C+J">J. Andrews</a>, <a href="/search/astro-ph?searchtype=author&query=Baade%2C+D">D. Baade</a>, <a href="/search/astro-ph?searchtype=author&query=Bostroem%2C+K+A">K. A. Bostroem</a>, <a href="/search/astro-ph?searchtype=author&query=Brown%2C+P+J">P. J. Brown</a>, <a href="/search/astro-ph?searchtype=author&query=Burns%2C+C+R">C. R. Burns</a>, <a href="/search/astro-ph?searchtype=author&query=Burrow%2C+A">A. Burrow</a>, <a href="/search/astro-ph?searchtype=author&query=Cikota%2C+A">A. Cikota</a>, <a href="/search/astro-ph?searchtype=author&query=de+Jaeger%2C+T">T. de Jaeger</a>, <a href="/search/astro-ph?searchtype=author&query=Do%2C+A">A. Do</a>, <a href="/search/astro-ph?searchtype=author&query=Dong%2C+Y">Y. Dong</a>, <a href="/search/astro-ph?searchtype=author&query=Dominguez%2C+I">I. Dominguez</a>, <a href="/search/astro-ph?searchtype=author&query=Fox%2C+O">O. Fox</a>, <a href="/search/astro-ph?searchtype=author&query=Galbany%2C+L">L. Galbany</a>, <a href="/search/astro-ph?searchtype=author&query=Hsiao%2C+E+Y">E. Y. Hsiao</a>, <a href="/search/astro-ph?searchtype=author&query=Krisciunas%2C+K">K. Krisciunas</a> , et al. (17 additional authors not shown) </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2404.17043v2-abstract-short" style="display: inline;"> We present a JWST MIRI/MRS spectrum (5-27 $\mathrm渭$m) of the Type Ia supernova (SN Ia), SN 2021aefx at $+415$ days past $B$-band maximum. The spectrum, which was obtained during the iron-dominated nebular phase, has been analyzed in combination with previous JWST observations of SN 2021aefx, to provide the first JWST time series analysis of an SN Ia. We find the temporal evolution of the [Co III]… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2404.17043v2-abstract-full').style.display = 'inline'; document.getElementById('2404.17043v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2404.17043v2-abstract-full" style="display: none;"> We present a JWST MIRI/MRS spectrum (5-27 $\mathrm渭$m) of the Type Ia supernova (SN Ia), SN 2021aefx at $+415$ days past $B$-band maximum. The spectrum, which was obtained during the iron-dominated nebular phase, has been analyzed in combination with previous JWST observations of SN 2021aefx, to provide the first JWST time series analysis of an SN Ia. We find the temporal evolution of the [Co III] 11.888 $\mathrm渭$m feature directly traces the decay of $^{56}$Co. The spectra, line profiles, and their evolution are analyzed with off-center delayed-detonation models. Best fits were obtained with White Dwarf (WD) central densities of $蟻_c=0.9-1.1\times 10^9$g cm$^{-3}$, a WD mass of M$_{\mathrm{WD}}$=1.33-1.35M$_\odot$, a WD magnetic field of $\approx10^6$G, and an off-center deflagration-to-detonation transition at $\approx$ 0.5 $M_\odot$ seen opposite to the line of sight of the observer (-30). The inner electron capture core is dominated by energy deposition from $纬$-rays whereas a broader region is dominated by positron deposition, placing SN 2021aefx at +415 d in the transitional phase of the evolution to the positron-dominated regime. The formerly `flat-tilted' profile at 9 $\mathrm渭$m now has significant contribution from [Ni IV], [Fe II], and [Fe III] and less from [Ar III], which alters the shape of the feature as positrons excite mostly the low-velocity Ar. Overall, the strength of the stable Ni features in the spectrum is dominated by positron transport rather than the Ni mass. Based on multi-dimensional models, our analysis is consistent with a single-spot, close-to-central ignition with an indication for a pre-existing turbulent velocity field, and excludes a multiple-spot, off-center ignition. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2404.17043v2-abstract-full').style.display = 'none'; document.getElementById('2404.17043v2-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 2 July, 2024; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 25 April, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> April 2024. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">Accepted for publication in ApJ</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2404.04235">arXiv:2404.04235</a> <span> [<a href="https://arxiv.org/pdf/2404.04235">pdf</a>, <a href="https://arxiv.org/format/2404.04235">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="High Energy Astrophysical Phenomena">astro-ph.HE</span> </div> </div> <p class="title is-5 mathjax"> Probing the Circumstellar Environment of highly luminous type IIn SN ASASSN-14il </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Dukiya%2C+N">Naveen Dukiya</a>, <a href="/search/astro-ph?searchtype=author&query=Gangopadhyay%2C+A">Anjasha Gangopadhyay</a>, <a href="/search/astro-ph?searchtype=author&query=Misra%2C+K">Kuntal Misra</a>, <a href="/search/astro-ph?searchtype=author&query=Hosseinzadeh%2C+G">Griffin Hosseinzadeh</a>, <a href="/search/astro-ph?searchtype=author&query=Bostroem%2C+K+A">K. Azalee Bostroem</a>, <a href="/search/astro-ph?searchtype=author&query=Ailawadhi%2C+B">Bhavya Ailawadhi</a>, <a href="/search/astro-ph?searchtype=author&query=Howell%2C+D+A">D. Andrew Howell</a>, <a href="/search/astro-ph?searchtype=author&query=Valenti%2C+S">Stefano Valenti</a>, <a href="/search/astro-ph?searchtype=author&query=Arcavi%2C+I">Iair Arcavi</a>, <a href="/search/astro-ph?searchtype=author&query=McCully%2C+C">Curtis McCully</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2404.04235v1-abstract-short" style="display: inline;"> We present long-term photometric and spectroscopic studies of Circumstellar Material (CSM)-Ejecta interacting supernova (SN) ASASSN-14il in the galaxy PGC 3093694. The SN reaches a peak $r$-band magnitude of $\sim$ $-20.3 \pm 0.2$ mag rivaling SN 2006tf and SN 2010jl. The multiband and the pseudo-bolometric lightcurve show a plateau lasting $\sim 50$ days. Semi-analytical CSM interaction models ca… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2404.04235v1-abstract-full').style.display = 'inline'; document.getElementById('2404.04235v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2404.04235v1-abstract-full" style="display: none;"> We present long-term photometric and spectroscopic studies of Circumstellar Material (CSM)-Ejecta interacting supernova (SN) ASASSN-14il in the galaxy PGC 3093694. The SN reaches a peak $r$-band magnitude of $\sim$ $-20.3 \pm 0.2$ mag rivaling SN 2006tf and SN 2010jl. The multiband and the pseudo-bolometric lightcurve show a plateau lasting $\sim 50$ days. Semi-analytical CSM interaction models can match the high luminosity and decline rates of the lightcurves but fail to faithfully represent the plateau region and the bumps in the lightcurves. The spectral evolution resembles the typical SNe IIn dominated by CSM interaction, showing blue-continuum and narrow Balmer lines. The lines are dominated by electron scattering at early epochs. The signatures of the underlying ejecta are visible as the broad component in the H$伪$ profile from as early as day 50, hinting at asymmetry in the CSM. A narrow component is persistent throughout the evolution. The SN shows remarkable photometric and spectroscopic similarity with SN 2015da. However, the different polarization in ASASSN-14il compared to SN 2015da suggests an alternative viewing angle. The late-time blueshift in the H$伪$ profiles supports dust formation in the post-shock CSM or ejecta. The mass-loss rate of 2-7 M$_{\odot} \mathrm{yr}^{-1}$ suggests a Luminous Blue Variable (LBV) progenitor in an eruptive phase for ASASSN-14il. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2404.04235v1-abstract-full').style.display = 'none'; document.getElementById('2404.04235v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 5 April, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> April 2024. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">26 pages, 12 figures, 9 tables, submitted in ApJ</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2403.02382">arXiv:2403.02382</a> <span> [<a href="https://arxiv.org/pdf/2403.02382">pdf</a>, <a href="https://arxiv.org/format/2403.02382">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="High Energy Astrophysical Phenomena">astro-ph.HE</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> </div> </div> <p class="title is-5 mathjax"> Final Moments II: Observational Properties and Physical Modeling of CSM-Interacting Type II Supernovae </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Jacobson-Gal%C3%A1n%2C+W+V">W. V. Jacobson-Gal谩n</a>, <a href="/search/astro-ph?searchtype=author&query=Dessart%2C+L">L. Dessart</a>, <a href="/search/astro-ph?searchtype=author&query=Davis%2C+K+W">K. W. Davis</a>, <a href="/search/astro-ph?searchtype=author&query=Kilpatrick%2C+C+D">C. D. Kilpatrick</a>, <a href="/search/astro-ph?searchtype=author&query=Margutti%2C+R">R. Margutti</a>, <a href="/search/astro-ph?searchtype=author&query=Foley%2C+R+J">R. J. Foley</a>, <a href="/search/astro-ph?searchtype=author&query=Chornock%2C+R">R. Chornock</a>, <a href="/search/astro-ph?searchtype=author&query=Terreran%2C+G">G. Terreran</a>, <a href="/search/astro-ph?searchtype=author&query=Hiramatsu%2C+D">D. Hiramatsu</a>, <a href="/search/astro-ph?searchtype=author&query=Newsome%2C+M">M. Newsome</a>, <a href="/search/astro-ph?searchtype=author&query=Gonzalez%2C+E+P">E. Padilla Gonzalez</a>, <a href="/search/astro-ph?searchtype=author&query=Pellegrino%2C+C">C. Pellegrino</a>, <a href="/search/astro-ph?searchtype=author&query=Howell%2C+D+A">D. A. Howell</a>, <a href="/search/astro-ph?searchtype=author&query=Filippenko%2C+A+V">A. V. Filippenko</a>, <a href="/search/astro-ph?searchtype=author&query=Anderson%2C+J+P">J. P. Anderson</a>, <a href="/search/astro-ph?searchtype=author&query=Angus%2C+C+R">C. R. Angus</a>, <a href="/search/astro-ph?searchtype=author&query=Auchettl%2C+K">K. Auchettl</a>, <a href="/search/astro-ph?searchtype=author&query=Bostroem%2C+K+A">K. A. Bostroem</a>, <a href="/search/astro-ph?searchtype=author&query=Brink%2C+T+G">T. G. Brink</a>, <a href="/search/astro-ph?searchtype=author&query=Cartier%2C+R">R. Cartier</a>, <a href="/search/astro-ph?searchtype=author&query=Coulter%2C+D+A">D. A. Coulter</a>, <a href="/search/astro-ph?searchtype=author&query=de+Boer%2C+T">T. de Boer</a>, <a href="/search/astro-ph?searchtype=author&query=Drout%2C+M+R">M. R. Drout</a>, <a href="/search/astro-ph?searchtype=author&query=Earl%2C+N">N. Earl</a>, <a href="/search/astro-ph?searchtype=author&query=Ertini%2C+K">K. Ertini</a> , et al. (30 additional authors not shown) </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2403.02382v1-abstract-short" style="display: inline;"> We present ultraviolet/optical/near-infrared observations and modeling of Type II supernovae (SNe II) whose early-time ($未t < 2$ days) spectra show transient, narrow emission lines from shock ionization of confined ($r < 10^{15}$ cm) circumstellar material (CSM). The observed electron-scattering broadened line profiles (i.e., IIn-like) of HI, He I/II, C III/IV, and N III/IV/V from the CSM persist… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2403.02382v1-abstract-full').style.display = 'inline'; document.getElementById('2403.02382v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2403.02382v1-abstract-full" style="display: none;"> We present ultraviolet/optical/near-infrared observations and modeling of Type II supernovae (SNe II) whose early-time ($未t < 2$ days) spectra show transient, narrow emission lines from shock ionization of confined ($r < 10^{15}$ cm) circumstellar material (CSM). The observed electron-scattering broadened line profiles (i.e., IIn-like) of HI, He I/II, C III/IV, and N III/IV/V from the CSM persist on a characteristic timescale ($t_{\rm IIn}$) that marks a transition to a lower-density CSM and the emergence of Doppler-broadened features from the fast-moving SN ejecta. Our sample, the largest to date, consists of 39 SNe with early-time IIn-like features in addition to 35 "comparison" SNe with no evidence of early-time IIn-like features, all with ultraviolet observations. The total sample consists of 50 unpublished objects with 474 previously unpublished spectra and 50 multiband light curves, collected primarily through the Young Supernova Experiment and Global Supernova Project collaborations. For all sample objects, we find a significant correlation between peak ultraviolet brightness and both $t_{\rm IIn}$ and the rise time, as well as evidence for enhanced peak luminosities in SNe II with IIn-like features. We quantify mass-loss rates and CSM density for the sample through matching of peak multiband absolute magnitudes, rise times, $t_{\rm IIn}$ and optical SN spectra with a grid of radiation hydrodynamics and non-local thermodynamic equilibrium (nLTE) radiative-transfer simulations. For our grid of models, all with the same underlying explosion, there is a trend between the duration of the electron-scattering broadened line profiles and inferred mass-loss rate: $t_{\rm IIn} \approx 3.8[\dot{M}/(0.01 \textrm{M}_{\odot} \textrm{yr}^{-1})]$ days. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2403.02382v1-abstract-full').style.display = 'none'; document.getElementById('2403.02382v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 4 March, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> March 2024. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">58 pages, 24 figures, submitted to ApJ. Supplementary figures available on Github (https://github.com/wynnjacobson-galan/Flash_Spectra_Sample). Data release following publication</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2403.00927">arXiv:2403.00927</a> <span> [<a href="https://arxiv.org/pdf/2403.00927">pdf</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="High Energy Astrophysical Phenomena">astro-ph.HE</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1051/0004-6361/202348642">10.1051/0004-6361/202348642 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> SN 2019nyk: A rapidly declining Type II supernova with early interaction signatures </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Dastidar%2C+R">Raya Dastidar</a>, <a href="/search/astro-ph?searchtype=author&query=Pignata%2C+G">Giuliano Pignata</a>, <a href="/search/astro-ph?searchtype=author&query=Dukiya%2C+N">Naveen Dukiya</a>, <a href="/search/astro-ph?searchtype=author&query=Misra%2C+K">Kuntal Misra</a>, <a href="/search/astro-ph?searchtype=author&query=Hiramatsu%2C+D">Daichi Hiramatsu</a>, <a href="/search/astro-ph?searchtype=author&query=Silva-Farf%C3%A1n%2C+J">Javier Silva-Farf谩n</a>, <a href="/search/astro-ph?searchtype=author&query=Howell%2C+D+A">D. Andrew Howell</a>, <a href="/search/astro-ph?searchtype=author&query=Bostroem%2C+K+A">K. Azalee Bostroem</a>, <a href="/search/astro-ph?searchtype=author&query=Singh%2C+M">Mridweeka Singh</a>, <a href="/search/astro-ph?searchtype=author&query=Gangopadhyay%2C+A">Anjasha Gangopadhyay</a>, <a href="/search/astro-ph?searchtype=author&query=Kumar%2C+A">Amit Kumar</a>, <a href="/search/astro-ph?searchtype=author&query=McCully%2C+C">Curtis McCully</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2403.00927v1-abstract-short" style="display: inline;"> We present an optical photometric and spectroscopic analysis of the fast-declining hydrogen-rich Type II supernova (SN) 2019nyk. The light curve properties of SN 2019nyk align well with those of other fast-declining Type II SNe, such as SNe 2013by and 2014G. SN 2019nyk exhibits a peak absolute magnitude of -18.09 $\pm$ 0.17 mag in the V band, followed by a rapid decline at 2.84 $\pm$ 0.03 mag (100… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2403.00927v1-abstract-full').style.display = 'inline'; document.getElementById('2403.00927v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2403.00927v1-abstract-full" style="display: none;"> We present an optical photometric and spectroscopic analysis of the fast-declining hydrogen-rich Type II supernova (SN) 2019nyk. The light curve properties of SN 2019nyk align well with those of other fast-declining Type II SNe, such as SNe 2013by and 2014G. SN 2019nyk exhibits a peak absolute magnitude of -18.09 $\pm$ 0.17 mag in the V band, followed by a rapid decline at 2.84 $\pm$ 0.03 mag (100 d)$^{-1}$ during the recombination phase. The early spectra of SN 2019nyk exhibit high-ionisation emission features as well as narrow H Balmer lines, persisting until 4.1 d since explosion, indicating the presence of circumstellar material (CSM) in close proximity. A comparison of these features with other Type II SNe displaying an early interaction reveals similarities between these features and those observed in SNe 2014G and 2023ixf. We also compared the early spectra to literature models, estimating a mass-loss rate of the order of 10$^{-3}$ M$_\odot$ yr$^{-1}$. Radiation hydrodynamical modelling of the light curve also suggests the mass loss from the progenitor within a short period prior to explosion, totalling 0.16 M$_\odot$ of material within 2900 R$_\odot$ of the progenitor. Furthermore, light curve modelling infers a zero-age main sequence mass of 15 M$_\odot$ for the progenitor, a progenitor radius of 1031 R$_\odot$, and an explosion energy of 1.1 $\times$ 10$^{51}$ erg. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2403.00927v1-abstract-full').style.display = 'none'; document.getElementById('2403.00927v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 1 March, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> March 2024. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">18 pages, 23 figures, accepted in A&A</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2401.07107">arXiv:2401.07107</a> <span> [<a href="https://arxiv.org/pdf/2401.07107">pdf</a>, <a href="https://arxiv.org/format/2401.07107">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="High Energy Astrophysical Phenomena">astro-ph.HE</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> </div> </div> <p class="title is-5 mathjax"> SN 2020udy: A new piece of the homogeneous bright group in the diverse Iax subclass </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Singh%2C+M">Mridweeka Singh</a>, <a href="/search/astro-ph?searchtype=author&query=Sahu%2C+D+K">Devendra K. Sahu</a>, <a href="/search/astro-ph?searchtype=author&query=Barna%2C+B">Barnabas Barna</a>, <a href="/search/astro-ph?searchtype=author&query=Gangopadhyay%2C+A">Anjasha Gangopadhyay</a>, <a href="/search/astro-ph?searchtype=author&query=Dastidar%2C+R">Raya Dastidar</a>, <a href="/search/astro-ph?searchtype=author&query=Teja%2C+R+S">Rishabh Singh Teja</a>, <a href="/search/astro-ph?searchtype=author&query=Misra%2C+K">Kuntal Misra</a>, <a href="/search/astro-ph?searchtype=author&query=Howell%2C+D+A">D. Andrew Howell</a>, <a href="/search/astro-ph?searchtype=author&query=Wang%2C+X">Xiaofeng Wang</a>, <a href="/search/astro-ph?searchtype=author&query=Mo%2C+J">Jun Mo</a>, <a href="/search/astro-ph?searchtype=author&query=Yan%2C+S">Shengyu Yan</a>, <a href="/search/astro-ph?searchtype=author&query=Hiramatsu%2C+D">Daichi Hiramatsu</a>, <a href="/search/astro-ph?searchtype=author&query=Pellegrino%2C+C">Craig Pellegrino</a>, <a href="/search/astro-ph?searchtype=author&query=Anupama%2C+G+C">G. C. Anupama</a>, <a href="/search/astro-ph?searchtype=author&query=Joshi%2C+A">Arti Joshi</a>, <a href="/search/astro-ph?searchtype=author&query=Bostroem%2C+K+A">K. Azalee Bostroem</a>, <a href="/search/astro-ph?searchtype=author&query=Burke%2C+J">Jamison Burke</a>, <a href="/search/astro-ph?searchtype=author&query=McCully%2C+C">Curtis McCully</a>, <a href="/search/astro-ph?searchtype=author&query=Subramanian%2C+R">Rama Subramanian V</a>, <a href="/search/astro-ph?searchtype=author&query=Li%2C+G">Gaici Li</a>, <a href="/search/astro-ph?searchtype=author&query=Xi%2C+G">Gaobo Xi</a>, <a href="/search/astro-ph?searchtype=author&query=Li%2C+X">Xin Li</a>, <a href="/search/astro-ph?searchtype=author&query=Li%2C+Z">Zhitong Li</a>, <a href="/search/astro-ph?searchtype=author&query=Srivastav%2C+S">Shubham Srivastav</a>, <a href="/search/astro-ph?searchtype=author&query=Im%2C+H">Hyobin Im</a> , et al. (1 additional authors not shown) </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2401.07107v1-abstract-short" style="display: inline;"> We present optical observations and analysis of a bright type Iax SN~2020udy hosted by NGC 0812. The light curve evolution of SN~2020udy is similar to other bright Iax SNe. Analytical modeling of the quasi bolometric light curves of SN 2020udy suggests that 0.08$\pm$0.01 M$_{\odot}$ of $^{56}$Ni would have been synthesized during the explosion. Spectral features of SN 2020udy are similar to the br… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2401.07107v1-abstract-full').style.display = 'inline'; document.getElementById('2401.07107v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2401.07107v1-abstract-full" style="display: none;"> We present optical observations and analysis of a bright type Iax SN~2020udy hosted by NGC 0812. The light curve evolution of SN~2020udy is similar to other bright Iax SNe. Analytical modeling of the quasi bolometric light curves of SN 2020udy suggests that 0.08$\pm$0.01 M$_{\odot}$ of $^{56}$Ni would have been synthesized during the explosion. Spectral features of SN 2020udy are similar to the bright members of type Iax class showing weak Si {\sc II} line. The late-time spectral sequence is mostly dominated by Iron Group Elements (IGEs) with broad emission lines. Abundance tomography modeling of the spectral time series of SN~2020udy using TARDIS indicates stratification in the outer ejecta, however, to confirm this, spectral modeling at a very early phase is required. After maximum light, uniform mixing of chemical elements is sufficient to explain the spectral evolution. Unlike the case of normal type Ia SNe, the photospheric approximation remains robust until +100 days, requiring an additional continuum source. Overall, the observational features of SN 2020udy are consistent with the deflagration of a Carbon-Oxygen white dwarf. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2401.07107v1-abstract-full').style.display = 'none'; document.getElementById('2401.07107v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 13 January, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> January 2024. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">18 pages, 17 figures, 3 tables, Accepted for publication in ApJ</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2401.04027">arXiv:2401.04027</a> <span> [<a href="https://arxiv.org/pdf/2401.04027">pdf</a>, <a href="https://arxiv.org/format/2401.04027">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="High Energy Astrophysical Phenomena">astro-ph.HE</span> </div> </div> <p class="title is-5 mathjax"> Circumstellar interaction signatures in the low luminosity type II SN 2021gmj </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Meza-Retamal%2C+N">Nicolas Meza-Retamal</a>, <a href="/search/astro-ph?searchtype=author&query=Dong%2C+Y">Yize Dong</a>, <a href="/search/astro-ph?searchtype=author&query=Bostroem%2C+K+A">K. Azalee Bostroem</a>, <a href="/search/astro-ph?searchtype=author&query=Valenti%2C+S">Stefano Valenti</a>, <a href="/search/astro-ph?searchtype=author&query=Galbany%2C+L">Lluis Galbany</a>, <a href="/search/astro-ph?searchtype=author&query=Pearson%2C+J">Jeniveve Pearson</a>, <a href="/search/astro-ph?searchtype=author&query=Hosseinzadeh%2C+G">Griffin Hosseinzadeh</a>, <a href="/search/astro-ph?searchtype=author&query=Andrews%2C+J+E">Jennifer E. Andrews</a>, <a href="/search/astro-ph?searchtype=author&query=Sand%2C+D+J">David J. Sand</a>, <a href="/search/astro-ph?searchtype=author&query=Jencson%2C+J+E">Jacob E. Jencson</a>, <a href="/search/astro-ph?searchtype=author&query=Janzen%2C+D">Daryl Janzen</a>, <a href="/search/astro-ph?searchtype=author&query=Lundquist%2C+M+J">Michael J. Lundquist</a>, <a href="/search/astro-ph?searchtype=author&query=Hoang%2C+E+T">Emily T. Hoang</a>, <a href="/search/astro-ph?searchtype=author&query=Wyatt%2C+S">Samuel Wyatt</a>, <a href="/search/astro-ph?searchtype=author&query=Brown%2C+P+J">Peter J. Brown</a>, <a href="/search/astro-ph?searchtype=author&query=Howell%2C+D+A">D. Andrew Howell</a>, <a href="/search/astro-ph?searchtype=author&query=Newsome%2C+M">Megan Newsome</a>, <a href="/search/astro-ph?searchtype=author&query=Gonzalez%2C+E+P">Estefania Padilla Gonzalez</a>, <a href="/search/astro-ph?searchtype=author&query=Pellegrino%2C+C">Craig Pellegrino</a>, <a href="/search/astro-ph?searchtype=author&query=Terreran%2C+G">Giacomo Terreran</a>, <a href="/search/astro-ph?searchtype=author&query=Kouprianov%2C+V">Vladimir Kouprianov</a>, <a href="/search/astro-ph?searchtype=author&query=Hiramatsu%2C+D">Daichi Hiramatsu</a>, <a href="/search/astro-ph?searchtype=author&query=Jha%2C+S+W">Saurabh W. Jha</a>, <a href="/search/astro-ph?searchtype=author&query=Smith%2C+N">Nathan Smith</a>, <a href="/search/astro-ph?searchtype=author&query=Haislip%2C+J">Joshua Haislip</a> , et al. (3 additional authors not shown) </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2401.04027v2-abstract-short" style="display: inline;"> We present comprehensive optical observations of SN~2021gmj, a Type II supernova (SN~II) discovered within a day of explosion by the Distance Less Than 40~Mpc (DLT40) survey. Follow-up observations show that SN~2021gmj is a low-luminosity SN~II (LL~SN~II), with a peak magnitude $M_V = -15.45$ and Fe~II velocity of $\sim 1800 \ \mathrm{km} \ \mathrm{s}^{-1}$ at 50 days past explosion. Using the exp… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2401.04027v2-abstract-full').style.display = 'inline'; document.getElementById('2401.04027v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2401.04027v2-abstract-full" style="display: none;"> We present comprehensive optical observations of SN~2021gmj, a Type II supernova (SN~II) discovered within a day of explosion by the Distance Less Than 40~Mpc (DLT40) survey. Follow-up observations show that SN~2021gmj is a low-luminosity SN~II (LL~SN~II), with a peak magnitude $M_V = -15.45$ and Fe~II velocity of $\sim 1800 \ \mathrm{km} \ \mathrm{s}^{-1}$ at 50 days past explosion. Using the expanding photosphere method, we derive a distance of $17.8^{+0.6}_{-0.4}$~Mpc. From the tail of the light curve we obtain a radioactive nickel mass of $0.014 \pm 0.001$ M$_{\odot}$. The presence of circumstellar material (CSM) is suggested by the early-time light curve, early spectra, and high-velocity H$伪$ in absorption. Analytical shock-cooling models of the light curve cannot reproduce the fast rise, supporting the idea that the early-time emission is partially powered by the interaction of the SN ejecta and CSM. The inferred low CSM mass of 0.025 M$_{\odot}$ in our hydrodynamic-modeling light curve analysis is also consistent with our spectroscopy. We observe a broad feature near 4600 脜, which may be high-ionization lines of C, N, or/and He~II. This feature is reproduced by radiation-hydrodynamic simulations of red supergiants with extended atmospheres. Several LL~SNe~II show similar spectral features, implying that high-density material around the progenitor may be common among them. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2401.04027v2-abstract-full').style.display = 'none'; document.getElementById('2401.04027v2-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 22 May, 2024; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 8 January, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> January 2024. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">Accepted version at ApJ</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2312.03842">arXiv:2312.03842</a> <span> [<a href="https://arxiv.org/pdf/2312.03842">pdf</a>, <a href="https://arxiv.org/format/2312.03842">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="High Energy Astrophysical Phenomena">astro-ph.HE</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.3847/1538-4357/ad4a72">10.3847/1538-4357/ad4a72 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Light-Curve Structure and Halpha Line Formation in the Tidal Disruption Event AT 2019azh </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Faris%2C+S">Sara Faris</a>, <a href="/search/astro-ph?searchtype=author&query=Arcavi%2C+I">Iair Arcavi</a>, <a href="/search/astro-ph?searchtype=author&query=Makrygianni%2C+L">Lydia Makrygianni</a>, <a href="/search/astro-ph?searchtype=author&query=Hiramatsu%2C+D">Daichi Hiramatsu</a>, <a href="/search/astro-ph?searchtype=author&query=Terreran%2C+G">Giacomo Terreran</a>, <a href="/search/astro-ph?searchtype=author&query=Farah%2C+J">Joseph Farah</a>, <a href="/search/astro-ph?searchtype=author&query=Howell%2C+D+A">D. Andrew Howell</a>, <a href="/search/astro-ph?searchtype=author&query=McCully%2C+C">Curtis McCully</a>, <a href="/search/astro-ph?searchtype=author&query=Newsome%2C+M">Megan Newsome</a>, <a href="/search/astro-ph?searchtype=author&query=Gonzalez%2C+E+P">Estefania Padilla Gonzalez</a>, <a href="/search/astro-ph?searchtype=author&query=Pellegrino%2C+C">Craig Pellegrino</a>, <a href="/search/astro-ph?searchtype=author&query=Bostroem%2C+K+A">K. Azalee Bostroem</a>, <a href="/search/astro-ph?searchtype=author&query=Abojanb%2C+W">Wiam Abojanb</a>, <a href="/search/astro-ph?searchtype=author&query=Lam%2C+M+C">Marco C. Lam</a>, <a href="/search/astro-ph?searchtype=author&query=Tomasella%2C+L">Lina Tomasella</a>, <a href="/search/astro-ph?searchtype=author&query=Brink%2C+T+G">Thomas G. Brink</a>, <a href="/search/astro-ph?searchtype=author&query=Filippenko%2C+A+V">Alexei V. Filippenko</a>, <a href="/search/astro-ph?searchtype=author&query=French%2C+K+D">K. Decker French</a>, <a href="/search/astro-ph?searchtype=author&query=Clark%2C+P">Peter Clark</a>, <a href="/search/astro-ph?searchtype=author&query=Graur%2C+O">Or Graur</a>, <a href="/search/astro-ph?searchtype=author&query=Leloudas%2C+G">Giorgos Leloudas</a>, <a href="/search/astro-ph?searchtype=author&query=Gromadzki%2C+M">Mariusz Gromadzki</a>, <a href="/search/astro-ph?searchtype=author&query=Anderson%2C+J+P">Joseph P. Anderson</a>, <a href="/search/astro-ph?searchtype=author&query=Nicholl%2C+M">Matt Nicholl</a>, <a href="/search/astro-ph?searchtype=author&query=Gutierrez%2C+C+P">Claudia P. Gutierrez</a> , et al. (11 additional authors not shown) </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2312.03842v2-abstract-short" style="display: inline;"> AT 2019azh is a H+He tidal disruption event (TDE) with one of the most extensive ultraviolet and optical data sets available to date. We present our photometric and spectroscopic observations of this event starting several weeks before and out to approximately two years after the g-band peak brightness and combine them with public photometric data. This extensive data set robustly reveals a change… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2312.03842v2-abstract-full').style.display = 'inline'; document.getElementById('2312.03842v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2312.03842v2-abstract-full" style="display: none;"> AT 2019azh is a H+He tidal disruption event (TDE) with one of the most extensive ultraviolet and optical data sets available to date. We present our photometric and spectroscopic observations of this event starting several weeks before and out to approximately two years after the g-band peak brightness and combine them with public photometric data. This extensive data set robustly reveals a change in the light-curve slope and a possible bump in the rising light curve of a TDE for the first time, which may indicate more than one dominant emission mechanism contributing to the pre-peak light curve. Indeed, we find that the MOSFiT-derived parameters of AT 2019azh, which assume reprocessed accretion as the sole source of emission, are not entirely self-consistent. We further confirm the relation seen in previous TDEs whereby the redder emission peaks later than the bluer emission. The post-peak bolometric light curve of AT 2019azh is better described by an exponential decline than by the canonical t^{-5/3} (and in fact any) power-law decline. We find a possible mid-infrared excess around the peak optical luminosity, but cannot determine its origin. In addition, we provide the earliest measurements of the Halpha emission-line evolution and find no significant time delay between the peak of the V-band light curve and that of the Halpha luminosity. These results can be used to constrain future models of TDE line formation and emission mechanisms in general. More pre-peak 1-2 days cadence observations of TDEs are required to determine whether the characteristics observed here are common among TDEs. More importantly, detailed emission models are needed to fully exploit such observations for understanding the emission physics of TDEs. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2312.03842v2-abstract-full').style.display = 'none'; document.getElementById('2312.03842v2-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 1 August, 2024; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 6 December, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> December 2023. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">Submitted to ApJ</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2310.16092">arXiv:2310.16092</a> <span> [<a href="https://arxiv.org/pdf/2310.16092">pdf</a>, <a href="https://arxiv.org/format/2310.16092">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="High Energy Astrophysical Phenomena">astro-ph.HE</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> </div> </div> <p class="title is-5 mathjax"> SN 2022jox: An extraordinarily ordinary Type II SN with Flash Spectroscopy </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Andrews%2C+J+E">Jennifer E. Andrews</a>, <a href="/search/astro-ph?searchtype=author&query=Pearson%2C+J">Jeniveve Pearson</a>, <a href="/search/astro-ph?searchtype=author&query=Hosseinzadeh%2C+G">Griffin Hosseinzadeh</a>, <a href="/search/astro-ph?searchtype=author&query=Bostroem%2C+K+A">K. Azalee Bostroem</a>, <a href="/search/astro-ph?searchtype=author&query=Dong%2C+Y">Yize Dong</a>, <a href="/search/astro-ph?searchtype=author&query=Shrestha%2C+M">Manisha Shrestha</a>, <a href="/search/astro-ph?searchtype=author&query=Jencson%2C+J+E">Jacob E. Jencson</a>, <a href="/search/astro-ph?searchtype=author&query=Sand%2C+D+J">David J. Sand</a>, <a href="/search/astro-ph?searchtype=author&query=Valenti%2C+S">S. Valenti</a>, <a href="/search/astro-ph?searchtype=author&query=Hoang%2C+E">Emily Hoang</a>, <a href="/search/astro-ph?searchtype=author&query=Janzen%2C+D">Daryl Janzen</a>, <a href="/search/astro-ph?searchtype=author&query=Lundquist%2C+M+J">M. J. Lundquist</a>, <a href="/search/astro-ph?searchtype=author&query=Meza%2C+N">Nicolas Meza</a>, <a href="/search/astro-ph?searchtype=author&query=Wyatt%2C+S">Samuel Wyatt</a>, <a href="/search/astro-ph?searchtype=author&query=Jha%2C+S+W">Saurabh W. Jha</a>, <a href="/search/astro-ph?searchtype=author&query=Simpson%2C+C">Chris Simpson</a>, <a href="/search/astro-ph?searchtype=author&query=Farah%2C+J">Joseph Farah</a>, <a href="/search/astro-ph?searchtype=author&query=Gonzalez%2C+E+P">Estefania Padilla Gonzalez</a>, <a href="/search/astro-ph?searchtype=author&query=Howell%2C+D+A">D. Andrew Howell</a>, <a href="/search/astro-ph?searchtype=author&query=McCully%2C+C">Curtis McCully</a>, <a href="/search/astro-ph?searchtype=author&query=Newsome%2C+M">Megan Newsome</a>, <a href="/search/astro-ph?searchtype=author&query=Pellegrino%2C+C">Craig Pellegrino</a>, <a href="/search/astro-ph?searchtype=author&query=Terreran%2C+G">Giacomo Terreran</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2310.16092v2-abstract-short" style="display: inline;"> We present high cadence optical and ultraviolet observations of the Type II supernova (SN), SN 2022jox which exhibits early spectroscopic high ionization flash features of \ion{H}{1}, \ion{He}{2}, \ion{C}{4}, and \ion{N}{4} that disappear within the first few days after explosion. SN 2022jox was discovered by the Distance Less than 40 Mpc (DLT40) survey $\sim$0.75 days after explosion with followu… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2310.16092v2-abstract-full').style.display = 'inline'; document.getElementById('2310.16092v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2310.16092v2-abstract-full" style="display: none;"> We present high cadence optical and ultraviolet observations of the Type II supernova (SN), SN 2022jox which exhibits early spectroscopic high ionization flash features of \ion{H}{1}, \ion{He}{2}, \ion{C}{4}, and \ion{N}{4} that disappear within the first few days after explosion. SN 2022jox was discovered by the Distance Less than 40 Mpc (DLT40) survey $\sim$0.75 days after explosion with followup spectra and UV photometry obtained within minutes of discovery. The SN reached a peak brightness of M$_V \sim$ $-$17.3 mag, and has an estimated $^{56}$Ni mass of 0.04 M$_{\odot}$, typical values for normal Type II SNe. The modeling of the early lightcurve and the strong flash signatures present in the optical spectra indicate interaction with circumstellar material (CSM) created from a progenitor with a mass loss rate of $\dot{M} \sim 10^{-3}-10^{-2}\ M_\odot\ \mathrm{yr}^{-1}$. There may also be some indication of late-time CSM interaction in the form of an emission line blueward of H$伪$ seen in spectra around 200 days. The mass-loss rate is much higher than the values typically associated with quiescent mass loss from red supergiants, the known progenitors of Type II SNe, but is comparable to inferred values from similar core collapse SNe with flash features, suggesting an eruptive event or a superwind in the progenitor in the months or years before explosion. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2310.16092v2-abstract-full').style.display = 'none'; document.getElementById('2310.16092v2-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 7 March, 2024; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 24 October, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> October 2023. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">ApJ, accepted 2024 Feb 14</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2310.09153">arXiv:2310.09153</a> <span> [<a href="https://arxiv.org/pdf/2310.09153">pdf</a>, <a href="https://arxiv.org/format/2310.09153">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="High Energy Astrophysical Phenomena">astro-ph.HE</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> </div> </div> <p class="title is-5 mathjax"> JWST MIRI/MRS Observations and Spectral Models of the Under-luminous Type Ia Supernova 2022xkq </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=DerKacy%2C+J+M">J. M. DerKacy</a>, <a href="/search/astro-ph?searchtype=author&query=Ashall%2C+C">C. Ashall</a>, <a href="/search/astro-ph?searchtype=author&query=Hoeflich%2C+P">P. Hoeflich</a>, <a href="/search/astro-ph?searchtype=author&query=Baron%2C+E">E. Baron</a>, <a href="/search/astro-ph?searchtype=author&query=Shahbandeh%2C+M">M. Shahbandeh</a>, <a href="/search/astro-ph?searchtype=author&query=Shappee%2C+B+J">B. J. Shappee</a>, <a href="/search/astro-ph?searchtype=author&query=Andrews%2C+J">J. Andrews</a>, <a href="/search/astro-ph?searchtype=author&query=Baade%2C+D">D. Baade</a>, <a href="/search/astro-ph?searchtype=author&query=Balangan%2C+E+F">E. F Balangan</a>, <a href="/search/astro-ph?searchtype=author&query=Bostroem%2C+K+A">K. A. Bostroem</a>, <a href="/search/astro-ph?searchtype=author&query=Brown%2C+P+J">P. J. Brown</a>, <a href="/search/astro-ph?searchtype=author&query=Burns%2C+C+R">C. R. Burns</a>, <a href="/search/astro-ph?searchtype=author&query=Burrow%2C+A">A. Burrow</a>, <a href="/search/astro-ph?searchtype=author&query=Cikota%2C+A">A. Cikota</a>, <a href="/search/astro-ph?searchtype=author&query=de+Jaeger%2C+T">T. de Jaeger</a>, <a href="/search/astro-ph?searchtype=author&query=Do%2C+A">A. Do</a>, <a href="/search/astro-ph?searchtype=author&query=Dong%2C+Y">Y. Dong</a>, <a href="/search/astro-ph?searchtype=author&query=Dominguez%2C+I">I. Dominguez</a>, <a href="/search/astro-ph?searchtype=author&query=Fox%2C+O">O. Fox</a>, <a href="/search/astro-ph?searchtype=author&query=Galbany%2C+L">L. Galbany</a>, <a href="/search/astro-ph?searchtype=author&query=Hoang%2C+E+T">E. T. Hoang</a>, <a href="/search/astro-ph?searchtype=author&query=Hsiao%2C+E+Y">E. Y. Hsiao</a>, <a href="/search/astro-ph?searchtype=author&query=Janzen%2C+D">D. Janzen</a>, <a href="/search/astro-ph?searchtype=author&query=Jencson%2C+J+E">J. E. Jencson</a>, <a href="/search/astro-ph?searchtype=author&query=Krisciunas%2C+K">K. Krisciunas</a> , et al. (22 additional authors not shown) </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2310.09153v2-abstract-short" style="display: inline;"> We present a JWST mid-infrared spectrum of the under-luminous Type Ia Supernova (SN Ia) 2022xkq, obtained with the medium-resolution spectrometer on the Mid-Infrared Instrument (MIRI) $\sim130$ days post-explosion. We identify the first MIR lines beyond 14 $渭$m in SN Ia observations. We find features unique to under-luminous SNe Ia, including: isolated emission of stable Ni, strong blends of [Ti I… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2310.09153v2-abstract-full').style.display = 'inline'; document.getElementById('2310.09153v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2310.09153v2-abstract-full" style="display: none;"> We present a JWST mid-infrared spectrum of the under-luminous Type Ia Supernova (SN Ia) 2022xkq, obtained with the medium-resolution spectrometer on the Mid-Infrared Instrument (MIRI) $\sim130$ days post-explosion. We identify the first MIR lines beyond 14 $渭$m in SN Ia observations. We find features unique to under-luminous SNe Ia, including: isolated emission of stable Ni, strong blends of [Ti II], and large ratios of singly ionized to doubly ionized species in both [Ar] and [Co]. Comparisons to normal-luminosity SNe Ia spectra at similar phases show a tentative trend between the width of the [Co III] 11.888 $渭$m feature and the SN light curve shape. Using non-LTE-multi-dimensional radiation hydro simulations and the observed electron capture elements we constrain the mass of the exploding white dwarf. The best-fitting model shows that SN 2022xkq is consistent with an off-center delayed-detonation explosion of a near-Chandrasekhar mass WD (M$_{\rm ej}$ $\approx 1.37$ M$_{\odot}$) of high-central density ($蟻_c \geq 2.0\times10^{9}$ g cm$^{-3}$) seen equator on, which produced M($^{56}$Ni) $= 0.324$ M$_{\odot}$ and M($^{58}$Ni) $\geq 0.06$ M$_{\odot}$. The observed line widths are consistent with the overall abundance distribution; and the narrow stable Ni lines indicate little to no mixing in the central regions, favoring central ignition of sub-sonic carbon burning followed by an off-center DDT beginning at a single point. Additional observations may further constrain the physics revealing the presence of additional species including Cr and Mn. Our work demonstrates the power of using the full coverage of MIRI in combination with detailed modeling to elucidate the physics of SNe Ia at a level not previously possible. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2310.09153v2-abstract-full').style.display = 'none'; document.getElementById('2310.09153v2-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 7 November, 2023; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 13 October, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> October 2023. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">31 pages, 18 figures, accepted to ApJ; updated to accepted version</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2310.08624">arXiv:2310.08624</a> <span> [<a href="https://arxiv.org/pdf/2310.08624">pdf</a>, <a href="https://arxiv.org/format/2310.08624">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Instrumentation and Methods for Astrophysics">astro-ph.IM</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="High Energy Astrophysical Phenomena">astro-ph.HE</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.3847/1538-4357/ad2170">10.3847/1538-4357/ad2170 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> SAGUARO: Time-domain Infrastructure for the Fourth Gravitational-wave Observing Run and Beyond </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Hosseinzadeh%2C+G">Griffin Hosseinzadeh</a>, <a href="/search/astro-ph?searchtype=author&query=Paterson%2C+K">Kerry Paterson</a>, <a href="/search/astro-ph?searchtype=author&query=Rastinejad%2C+J+C">Jillian C. Rastinejad</a>, <a href="/search/astro-ph?searchtype=author&query=Shrestha%2C+M">Manisha Shrestha</a>, <a href="/search/astro-ph?searchtype=author&query=Daly%2C+P+N">Philip N. Daly</a>, <a href="/search/astro-ph?searchtype=author&query=Lundquist%2C+M+J">Michael J. Lundquist</a>, <a href="/search/astro-ph?searchtype=author&query=Sand%2C+D+J">David J. Sand</a>, <a href="/search/astro-ph?searchtype=author&query=Fong%2C+W">Wen-fai Fong</a>, <a href="/search/astro-ph?searchtype=author&query=Bostroem%2C+K+A">K. Azalee Bostroem</a>, <a href="/search/astro-ph?searchtype=author&query=Hall%2C+S">Saarah Hall</a>, <a href="/search/astro-ph?searchtype=author&query=Wyatt%2C+S+D">Samuel D. Wyatt</a>, <a href="/search/astro-ph?searchtype=author&query=Gibbs%2C+A+R">Alex R. Gibbs</a>, <a href="/search/astro-ph?searchtype=author&query=Christensen%2C+E">Eric Christensen</a>, <a href="/search/astro-ph?searchtype=author&query=Lindstrom%2C+W">William Lindstrom</a>, <a href="/search/astro-ph?searchtype=author&query=Nation%2C+J">Jonathan Nation</a>, <a href="/search/astro-ph?searchtype=author&query=Chatelain%2C+J">Joseph Chatelain</a>, <a href="/search/astro-ph?searchtype=author&query=McCully%2C+C">Curtis McCully</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2310.08624v3-abstract-short" style="display: inline;"> We present upgraded infrastructure for Searches after Gravitational Waves Using ARizona Observatories (SAGUARO) during LIGO, Virgo, and KAGRA's fourth gravitational-wave (GW) observing run (O4). These upgrades implement many of the lessons we learned after a comprehensive analysis of potential electromagnetic counterparts to the GWs discovered during the previous observing run. We have developed a… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2310.08624v3-abstract-full').style.display = 'inline'; document.getElementById('2310.08624v3-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2310.08624v3-abstract-full" style="display: none;"> We present upgraded infrastructure for Searches after Gravitational Waves Using ARizona Observatories (SAGUARO) during LIGO, Virgo, and KAGRA's fourth gravitational-wave (GW) observing run (O4). These upgrades implement many of the lessons we learned after a comprehensive analysis of potential electromagnetic counterparts to the GWs discovered during the previous observing run. We have developed a new web-based target and observation manager (TOM) that allows us to coordinate sky surveys, vet potential counterparts, and trigger follow-up observations from one centralized portal. The TOM includes software that aggregates all publicly available information on the light curves and possible host galaxies of targets, allowing us to rule out potential contaminants like active galactic nuclei, variable stars, solar-system objects, and preexisting supernovae, as well as to assess the viability of any plausible counterparts. We have also upgraded our image-subtraction pipeline by assembling deeper reference images and training a new neural network-based real-bogus classifier. These infrastructure upgrades will aid coordination by enabling the prompt reporting of observations, discoveries, and analysis to the GW follow-up community, and put SAGUARO in an advantageous position to discover kilonovae in the remainder of O4 and beyond. Many elements of our open-source software stack have broad utility beyond multimessenger astronomy, and will be particularly relevant in the "big data" era of transient discoveries by the Vera C. Rubin Observatory. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2310.08624v3-abstract-full').style.display = 'none'; document.getElementById('2310.08624v3-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 17 October, 2024; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 12 October, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> October 2023. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">updated to match accepted version</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> The Astrophysical Journal, 964:35 (18pp), 2024 March 20 </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2310.01498">arXiv:2310.01498</a> <span> [<a href="https://arxiv.org/pdf/2310.01498">pdf</a>, <a href="https://arxiv.org/format/2310.01498">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="High Energy Astrophysical Phenomena">astro-ph.HE</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> </div> </div> <p class="title is-5 mathjax"> Considering the Single and Binary Origins of the Type IIP SN 2017eaw </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Bostroem%2C+K+A">K. Azalee Bostroem</a>, <a href="/search/astro-ph?searchtype=author&query=Zapartas%2C+E">Emmanouil Zapartas</a>, <a href="/search/astro-ph?searchtype=author&query=Koplitz%2C+B">Brad Koplitz</a>, <a href="/search/astro-ph?searchtype=author&query=Williams%2C+B+F">Benjamin F. Williams</a>, <a href="/search/astro-ph?searchtype=author&query=Tran%2C+D">Debby Tran</a>, <a href="/search/astro-ph?searchtype=author&query=Dolphin%2C+A">Andrew Dolphin</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2310.01498v1-abstract-short" style="display: inline;"> Current population synthesis modeling suggests that 30-50% of Type II supernovae originate from binary progenitors, however, the identification of a binary progenitor is challenging. One indicator of a binary progenitor is that the surrounding stellar population is too old to contain a massive single star.Measurements of the progenitor mass of SN 2017eaw are starkly divided between observations ma… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2310.01498v1-abstract-full').style.display = 'inline'; document.getElementById('2310.01498v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2310.01498v1-abstract-full" style="display: none;"> Current population synthesis modeling suggests that 30-50% of Type II supernovae originate from binary progenitors, however, the identification of a binary progenitor is challenging. One indicator of a binary progenitor is that the surrounding stellar population is too old to contain a massive single star.Measurements of the progenitor mass of SN 2017eaw are starkly divided between observations made temporally close to core-collapse which show a progenitor mass of 13-15 solar masses (final helium core mass of 4.4 to 6.0 solar masses - which is a more informative property than initial mass) and those from the stellar population surrounding the SN which find M<10.8 solar masses (helium core mass <3.4 solar masses). In this paper, we reanalyze the surrounding stellar population with improved astrometry and photometry, finding a median age of 16.8 (+3.2, -1.0) Myr for all stars younger than 50 Myr (helium core mass of 4.7 solar masses) and 85.9 (+3.2, -6.5) Myr for stars younger than 150 Myr. 16.8 Myr is now consistent with the helium core mass range derived from the temporally near explosion observations for single stars. Applying the combined constraints to population synthesis models, we determine that the probability of the progenitor of SN 2017eaw being an initially single-star is 65% compared to 35% for prior binary interaction. 85.9 Myr is inconsistent with any formation scenarios. We demonstrate that combining progenitor age constraints with helium core mass estimates from red supergiant SED modeling, late-time spectra, and indirectly from light curve modeling can help to differentiate single and binary progenitor scenarios and provide a framework for the application of this technique to future observations. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2310.01498v1-abstract-full').style.display = 'none'; document.getElementById('2310.01498v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 2 October, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> October 2023. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">Accepted to AJ</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2310.00162">arXiv:2310.00162</a> <span> [<a href="https://arxiv.org/pdf/2310.00162">pdf</a>, <a href="https://arxiv.org/format/2310.00162">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="High Energy Astrophysical Phenomena">astro-ph.HE</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> </div> </div> <p class="title is-5 mathjax"> Evidence of weak circumstellar medium interaction in the Type II SN 2023axu </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Shrestha%2C+M">Manisha Shrestha</a>, <a href="/search/astro-ph?searchtype=author&query=Pearson%2C+J">Jeniveve Pearson</a>, <a href="/search/astro-ph?searchtype=author&query=Wyatt%2C+S">Samuel Wyatt</a>, <a href="/search/astro-ph?searchtype=author&query=Sand%2C+D+J">David J. Sand</a>, <a href="/search/astro-ph?searchtype=author&query=Hosseinzadeh%2C+G">Griffin Hosseinzadeh</a>, <a href="/search/astro-ph?searchtype=author&query=Bostroem%2C+K+A">K. Azalee Bostroem</a>, <a href="/search/astro-ph?searchtype=author&query=Andrews%2C+J+E">Jennifer E. Andrews</a>, <a href="/search/astro-ph?searchtype=author&query=Dong%2C+Y">Yize Dong</a>, <a href="/search/astro-ph?searchtype=author&query=Hoang%2C+E">Emily Hoang</a>, <a href="/search/astro-ph?searchtype=author&query=Janzen%2C+D">Daryl Janzen</a>, <a href="/search/astro-ph?searchtype=author&query=Jencson%2C+J+E">Jacob E. Jencson</a>, <a href="/search/astro-ph?searchtype=author&query=Lundquist%2C+M+J">M. J. Lundquist</a>, <a href="/search/astro-ph?searchtype=author&query=Mehta%2C+D">Darshana Mehta</a>, <a href="/search/astro-ph?searchtype=author&query=Retamal%2C+4+N+M">4 Nicolas Meza Retamal</a>, <a href="/search/astro-ph?searchtype=author&query=Valenti%2C+S">Stefano Valenti</a>, <a href="/search/astro-ph?searchtype=author&query=Rastinejad%2C+J+C">Jillian C. Rastinejad</a>, <a href="/search/astro-ph?searchtype=author&query=Daly%2C+P">Phil Daly</a>, <a href="/search/astro-ph?searchtype=author&query=Porter%2C+D">Dallan Porter</a>, <a href="/search/astro-ph?searchtype=author&query=Hinz%2C+J">Joannah Hinz</a>, <a href="/search/astro-ph?searchtype=author&query=Self%2C+S">Skyler Self</a>, <a href="/search/astro-ph?searchtype=author&query=Weiner%2C+B">Benjamin Weiner</a>, <a href="/search/astro-ph?searchtype=author&query=Williams%2C+G+G">Grant G. Williams</a>, <a href="/search/astro-ph?searchtype=author&query=Hiramatsu%2C+D">Daichi Hiramatsu</a>, <a href="/search/astro-ph?searchtype=author&query=Howell%2C+D+A">D. Andrew Howell</a>, <a href="/search/astro-ph?searchtype=author&query=McCully%2C+C">Curtis McCully</a> , et al. (12 additional authors not shown) </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2310.00162v1-abstract-short" style="display: inline;"> We present high-cadence photometric and spectroscopic observations of SN~2023axu, a classical Type II supernova with an absolute $V$-band peak magnitude of $-16.5 \pm 0.1$ mag. SN~2023axu was discovered by the Distance Less Than 40 Mpc (DLT40) survey within 1 day of the last non-detection in the nearby galaxy NGC 2283 at 13.7 Mpc. We modeled the early light curve using a recently updated shock coo… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2310.00162v1-abstract-full').style.display = 'inline'; document.getElementById('2310.00162v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2310.00162v1-abstract-full" style="display: none;"> We present high-cadence photometric and spectroscopic observations of SN~2023axu, a classical Type II supernova with an absolute $V$-band peak magnitude of $-16.5 \pm 0.1$ mag. SN~2023axu was discovered by the Distance Less Than 40 Mpc (DLT40) survey within 1 day of the last non-detection in the nearby galaxy NGC 2283 at 13.7 Mpc. We modeled the early light curve using a recently updated shock cooling model that includes the effects of line blanketing and found the explosion epoch to be MJD 59971.48 $\pm$ 0.03 and the probable progenitor to be a red supergiant with a radius of 417 $\pm$ 28 $R_\odot$. The shock cooling model cannot match the rise of observed data in the $r$ and $i$ bands and underpredicts the overall UV data which points to possible interaction with circumstellar material. This interpretation is further supported by spectral behavior. We see a ledge feature around 4600 脜 in the very early spectra (+1.1 and +1.5 days after the explosion) which can be a sign of circumstellar interaction. The signs of circumstellar material are further bolstered by the presence of absorption features blueward of H$伪$ and H$尾$ at day $>$40 which is also generally attributed to circumstellar interaction. Our analysis shows the need for high-cadence early photometric and spectroscopic data to decipher the mass-loss history of the progenitor. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2310.00162v1-abstract-full').style.display = 'none'; document.getElementById('2310.00162v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 29 September, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> October 2023. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">18 pages, 12 figures, to be submitted to the AAS Journals</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2309.13113">arXiv:2309.13113</a> <span> [<a href="https://arxiv.org/pdf/2309.13113">pdf</a>, <a href="https://arxiv.org/format/2309.13113">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1051/0004-6361/202346930">10.1051/0004-6361/202346930 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Constraints on the multiplicity of the most massive stars known: R136 a1, a2, a3, and c </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Shenar%2C+T">T. Shenar</a>, <a href="/search/astro-ph?searchtype=author&query=Sana%2C+H">H. Sana</a>, <a href="/search/astro-ph?searchtype=author&query=Crowther%2C+P+A">P. A. Crowther</a>, <a href="/search/astro-ph?searchtype=author&query=Bostroem%2C+K+A">K. A. Bostroem</a>, <a href="/search/astro-ph?searchtype=author&query=Mahy%2C+L">L. Mahy</a>, <a href="/search/astro-ph?searchtype=author&query=Najarro%2C+F">F. Najarro</a>, <a href="/search/astro-ph?searchtype=author&query=Oskinova%2C+L">L. Oskinova</a>, <a href="/search/astro-ph?searchtype=author&query=Sander%2C+A+A+C">A. A. C. Sander</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2309.13113v1-abstract-short" style="display: inline;"> The most massive stars known to date are R 136 a1, a2, a3, and c within the central cluster R 136a of the Tarantula nebula in the Large Magellanic Cloud (LMC), with reported masses in excess of 150-200$M_\odot$. However, the mass estimation of these stars relies on the assumption that they are single. We collected three epochs of spectroscopy for R 136 a1, a2, a3, and c with the Space Telescope Im… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2309.13113v1-abstract-full').style.display = 'inline'; document.getElementById('2309.13113v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2309.13113v1-abstract-full" style="display: none;"> The most massive stars known to date are R 136 a1, a2, a3, and c within the central cluster R 136a of the Tarantula nebula in the Large Magellanic Cloud (LMC), with reported masses in excess of 150-200$M_\odot$. However, the mass estimation of these stars relies on the assumption that they are single. We collected three epochs of spectroscopy for R 136 a1, a2, a3, and c with the Space Telescope Imaging Spectrograph (STIS) of the Hubble Space Telescope (HST) in the years 2020-2021 to probe potential radial-velocity (RV) variations. We combine these epochs with an additional HST/STIS observation taken in 2012. We use cross-correlation to quantify the RVs, and establish constraints on possible companions to these stars up to periods of ~10 yr. Objects are classified as binaries when the peak-to-peak RV shifts exceed 50 km/s, and when the RV shift is significant with respect to errors. R 136 a1, a2, and a3 do not satisfy the binary criteria and are thus classified as putatively single, although formal peak-to-peak RV variability on the level 40 km/s is noted for a3. Only R 136 c is classified as binary, in agreement with literature. We can generally rule out massive companions (M2 > ~50 Msun) to R 136 a1, a2, and a3 out to orbital periods of < 1 yr (separations < 5 au) at 95% confidence, or out to tens of years (separations < ~100 au) at 50% confidence. Highly eccentric binaries (e > ~0.9) or twin companions with similar spectra could evade detection down to shorter periods (> ~10 d), though their presence is not supported by the relative X-ray faintness of R 136 a1, a2, and a3. We derive a preliminary orbital solution with a 17.2 d period for the X-ray bright binary R 136 c, though more data are needed to conclusively derive its orbit. Our study supports a lower bound of 150-200 $M_\odot$ on the upper-mass limit at LMC metallicity <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2309.13113v1-abstract-full').style.display = 'none'; document.getElementById('2309.13113v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 22 September, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> September 2023. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">Accepted to A&A</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> A&A 679, A36 (2023) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2309.10054">arXiv:2309.10054</a> <span> [<a href="https://arxiv.org/pdf/2309.10054">pdf</a>, <a href="https://arxiv.org/format/2309.10054">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="High Energy Astrophysical Phenomena">astro-ph.HE</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> </div> </div> <p class="title is-5 mathjax"> Strong Carbon Features and a Red Early Color in the Underluminous Type Ia SN 2022xkq </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Pearson%2C+J">Jeniveve Pearson</a>, <a href="/search/astro-ph?searchtype=author&query=Sand%2C+D+J">David J. Sand</a>, <a href="/search/astro-ph?searchtype=author&query=Lundqvist%2C+P">Peter Lundqvist</a>, <a href="/search/astro-ph?searchtype=author&query=Galbany%2C+L">Llu铆s Galbany</a>, <a href="/search/astro-ph?searchtype=author&query=Andrews%2C+J+E">Jennifer E. Andrews</a>, <a href="/search/astro-ph?searchtype=author&query=Bostroem%2C+K+A">K. Azalee Bostroem</a>, <a href="/search/astro-ph?searchtype=author&query=Dong%2C+Y">Yize Dong</a>, <a href="/search/astro-ph?searchtype=author&query=Hoang%2C+E">Emily Hoang</a>, <a href="/search/astro-ph?searchtype=author&query=Hosseinzadeh%2C+G">Griffin Hosseinzadeh</a>, <a href="/search/astro-ph?searchtype=author&query=Janzen%2C+D">Daryl Janzen</a>, <a href="/search/astro-ph?searchtype=author&query=Jencson%2C+J+E">Jacob E. Jencson</a>, <a href="/search/astro-ph?searchtype=author&query=Lundquist%2C+M+J">Michael J. Lundquist</a>, <a href="/search/astro-ph?searchtype=author&query=Mehta%2C+D">Darshana Mehta</a>, <a href="/search/astro-ph?searchtype=author&query=Retamal%2C+N+M">Nicol谩s Meza Retamal</a>, <a href="/search/astro-ph?searchtype=author&query=Shrestha%2C+M">Manisha Shrestha</a>, <a href="/search/astro-ph?searchtype=author&query=Valenti%2C+S">Stefano Valenti</a>, <a href="/search/astro-ph?searchtype=author&query=Wyatt%2C+S">Samuel Wyatt</a>, <a href="/search/astro-ph?searchtype=author&query=Anderson%2C+J+P">Joseph P. Anderson</a>, <a href="/search/astro-ph?searchtype=author&query=Ashall%2C+C">Chris Ashall</a>, <a href="/search/astro-ph?searchtype=author&query=Auchettl%2C+K">Katie Auchettl</a>, <a href="/search/astro-ph?searchtype=author&query=Baron%2C+E">Eddie Baron</a>, <a href="/search/astro-ph?searchtype=author&query=Blondin%2C+S">St茅phane Blondin</a>, <a href="/search/astro-ph?searchtype=author&query=Burns%2C+C+R">Christopher R. Burns</a>, <a href="/search/astro-ph?searchtype=author&query=Cai%2C+Y">Yongzhi Cai</a>, <a href="/search/astro-ph?searchtype=author&query=Chen%2C+T">Ting-Wan Chen</a> , et al. (63 additional authors not shown) </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2309.10054v2-abstract-short" style="display: inline;"> We present optical, infrared, ultraviolet, and radio observations of SN 2022xkq, an underluminous fast-declining type Ia supernova (SN Ia) in NGC 1784 ($\mathrm{D}\approx31$ Mpc), from $<1$ to 180 days after explosion. The high-cadence observations of SN 2022xkq, a photometrically transitional and spectroscopically 91bg-like SN Ia, cover the first days and weeks following explosion which are criti… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2309.10054v2-abstract-full').style.display = 'inline'; document.getElementById('2309.10054v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2309.10054v2-abstract-full" style="display: none;"> We present optical, infrared, ultraviolet, and radio observations of SN 2022xkq, an underluminous fast-declining type Ia supernova (SN Ia) in NGC 1784 ($\mathrm{D}\approx31$ Mpc), from $<1$ to 180 days after explosion. The high-cadence observations of SN 2022xkq, a photometrically transitional and spectroscopically 91bg-like SN Ia, cover the first days and weeks following explosion which are critical to distinguishing between explosion scenarios. The early light curve of SN 2022xkq has a red early color and exhibits a flux excess which is more prominent in redder bands; this is the first time such a feature has been seen in a transitional/91bg-like SN Ia. We also present 92 optical and 19 near-infrared (NIR) spectra, beginning 0.4 days after explosion in the optical and 2.6 days after explosion in the NIR. SN 2022xkq exhibits a long-lived C I 1.0693 $渭$m feature which persists until 5 days post-maximum. We also detect C II $位$6580 in the pre-maximum optical spectra. These lines are evidence for unburnt carbon that is difficult to reconcile with the double detonation of a sub-Chandrasekhar mass white dwarf. No existing explosion model can fully explain the photometric and spectroscopic dataset of SN 2022xkq, but the considerable breadth of the observations is ideal for furthering our understanding of the processes which produce faint SNe Ia. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2309.10054v2-abstract-full').style.display = 'none'; document.getElementById('2309.10054v2-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 6 October, 2023; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 18 September, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> September 2023. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">38 pages, 16 figures, accepted for publication in ApJ, the figure 15 input models and synthetic spectra are now available at https://zenodo.org/record/8379254</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2309.09433">arXiv:2309.09433</a> <span> [<a href="https://arxiv.org/pdf/2309.09433">pdf</a>, <a href="https://arxiv.org/format/2309.09433">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="High Energy Astrophysical Phenomena">astro-ph.HE</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.3847/1538-4357/ad710e">10.3847/1538-4357/ad710e <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Characterizing the Rapid Hydrogen Disappearance in SN2022crv: Evidence of a Continuum between Type Ib and IIb Supernova Properties </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Dong%2C+Y">Yize Dong</a>, <a href="/search/astro-ph?searchtype=author&query=Valenti%2C+S">Stefano Valenti</a>, <a href="/search/astro-ph?searchtype=author&query=Ashall%2C+C">Chris Ashall</a>, <a href="/search/astro-ph?searchtype=author&query=Williamson%2C+M">Marc Williamson</a>, <a href="/search/astro-ph?searchtype=author&query=Sand%2C+D+J">David J. Sand</a>, <a href="/search/astro-ph?searchtype=author&query=Van+Dyk%2C+S+D">Schuyler D. Van Dyk</a>, <a href="/search/astro-ph?searchtype=author&query=Filippenko%2C+A+V">Alexei V. Filippenko</a>, <a href="/search/astro-ph?searchtype=author&query=Jha%2C+S+W">Saurabh W. Jha</a>, <a href="/search/astro-ph?searchtype=author&query=Lundquist%2C+M">Michael Lundquist</a>, <a href="/search/astro-ph?searchtype=author&query=Modjaz%2C+M">Maryam Modjaz</a>, <a href="/search/astro-ph?searchtype=author&query=Andrews%2C+J+E">Jennifer E. Andrews</a>, <a href="/search/astro-ph?searchtype=author&query=Jencson%2C+J+E">Jacob E. Jencson</a>, <a href="/search/astro-ph?searchtype=author&query=Hosseinzadeh%2C+G">Griffin Hosseinzadeh</a>, <a href="/search/astro-ph?searchtype=author&query=Pearson%2C+J">Jeniveve Pearson</a>, <a href="/search/astro-ph?searchtype=author&query=Kwok%2C+L+A">Lindsey A. Kwok</a>, <a href="/search/astro-ph?searchtype=author&query=Boland%2C+T">Teresa Boland</a>, <a href="/search/astro-ph?searchtype=author&query=Hsiao%2C+E+Y">Eric Y. Hsiao</a>, <a href="/search/astro-ph?searchtype=author&query=Smith%2C+N">Nathan Smith</a>, <a href="/search/astro-ph?searchtype=author&query=Elias-Rosa%2C+N">Nancy Elias-Rosa</a>, <a href="/search/astro-ph?searchtype=author&query=Srivastav%2C+S">Shubham Srivastav</a>, <a href="/search/astro-ph?searchtype=author&query=Smartt%2C+S">Stephen Smartt</a>, <a href="/search/astro-ph?searchtype=author&query=Fulton%2C+M">Michael Fulton</a>, <a href="/search/astro-ph?searchtype=author&query=Zheng%2C+W">WeiKang Zheng</a>, <a href="/search/astro-ph?searchtype=author&query=Brink%2C+T+G">Thomas G. Brink</a>, <a href="/search/astro-ph?searchtype=author&query=Shahbandeh%2C+M">Melissa Shahbandeh</a> , et al. (30 additional authors not shown) </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2309.09433v2-abstract-short" style="display: inline;"> We present optical and near-infrared observations of SN~2022crv, a stripped envelope supernova in NGC~3054, discovered within 12 hrs of explosion by the Distance Less Than 40 Mpc Survey. We suggest SN~2022crv is a transitional object on the continuum between SNe Ib and SNe IIb. A high-velocity hydrogen feature ($\sim$$-$20,000 -- $-$16,000 $\rm km\,s^{-1}$) was conspicuous in SN~2022crv at early p… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2309.09433v2-abstract-full').style.display = 'inline'; document.getElementById('2309.09433v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2309.09433v2-abstract-full" style="display: none;"> We present optical and near-infrared observations of SN~2022crv, a stripped envelope supernova in NGC~3054, discovered within 12 hrs of explosion by the Distance Less Than 40 Mpc Survey. We suggest SN~2022crv is a transitional object on the continuum between SNe Ib and SNe IIb. A high-velocity hydrogen feature ($\sim$$-$20,000 -- $-$16,000 $\rm km\,s^{-1}$) was conspicuous in SN~2022crv at early phases, and then quickly disappeared around maximum light. By comparing with hydrodynamic modeling, we find that a hydrogen envelope of $\sim 10^{-3}$ \msun{} can reproduce the behaviour of the hydrogen feature observed in SN~2022crv. The early light curve of SN~2022crv did not show envelope cooling emission, implying that SN~2022crv had a compact progenitor with extremely low amount of hydrogen. The analysis of the nebular spectra shows that SN~2022crv is consistent with the explosion of a He star with a final mass of $\sim$4.5 -- 5.6 \msun{} that has evolved from a $\sim$16 -- 22 \msun{} zero-age main sequence star in a binary system with about 1.0 -- 1.7 \msun{} of oxygen finally synthesized in the core. The high metallicity at the supernova site indicates that the progenitor experienced a strong stellar wind mass loss. In order to retain a small amount of residual hydrogen at such a high metallicity, the initial orbital separation of the binary system is likely larger than $\sim$1000~$\rm R_{\odot}$. The near-infrared spectra of SN~2022crv show a unique absorption feature on the blue side of He I line at $\sim$1.005~$渭$m. This is the first time that such a feature has been observed in a Type Ib/IIb, and could be due to \ion{Sr}{2}. Further detailed modelling on SN~2022crv can shed light on the progenitor and the origin of the mysterious absorption feature in the near infrared. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2309.09433v2-abstract-full').style.display = 'none'; document.getElementById('2309.09433v2-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 29 October, 2024; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 17 September, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> September 2023. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">accepted for publication in ApJ</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> ApJ 974 316 (2024) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2308.12450">arXiv:2308.12450</a> <span> [<a href="https://arxiv.org/pdf/2308.12450">pdf</a>, <a href="https://arxiv.org/format/2308.12450">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="High Energy Astrophysical Phenomena">astro-ph.HE</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.3847/1538-4357/ad2c0d">10.3847/1538-4357/ad2c0d <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Ground-based and JWST Observations of SN 2022pul: II. Evidence from Nebular Spectroscopy for a Violent Merger in a Peculiar Type-Ia Supernova </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Kwok%2C+L+A">Lindsey A. Kwok</a>, <a href="/search/astro-ph?searchtype=author&query=Siebert%2C+M+R">Matthew R. Siebert</a>, <a href="/search/astro-ph?searchtype=author&query=Johansson%2C+J">Joel Johansson</a>, <a href="/search/astro-ph?searchtype=author&query=Jha%2C+S+W">Saurabh W. Jha</a>, <a href="/search/astro-ph?searchtype=author&query=Blondin%2C+S">Stephane Blondin</a>, <a href="/search/astro-ph?searchtype=author&query=Dessart%2C+L">Luc Dessart</a>, <a href="/search/astro-ph?searchtype=author&query=Foley%2C+R+J">Ryan J. Foley</a>, <a href="/search/astro-ph?searchtype=author&query=Hillier%2C+D+J">D. John Hillier</a>, <a href="/search/astro-ph?searchtype=author&query=Larison%2C+C">Conor Larison</a>, <a href="/search/astro-ph?searchtype=author&query=Pakmor%2C+R">Ruediger Pakmor</a>, <a href="/search/astro-ph?searchtype=author&query=Temim%2C+T">Tea Temim</a>, <a href="/search/astro-ph?searchtype=author&query=Andrews%2C+J+E">Jennifer E. Andrews</a>, <a href="/search/astro-ph?searchtype=author&query=Auchettl%2C+K">Katie Auchettl</a>, <a href="/search/astro-ph?searchtype=author&query=Badenes%2C+C">Carles Badenes</a>, <a href="/search/astro-ph?searchtype=author&query=Barna%2C+B">Barnabas Barna</a>, <a href="/search/astro-ph?searchtype=author&query=Bostroem%2C+K+A">K. Azalee Bostroem</a>, <a href="/search/astro-ph?searchtype=author&query=Newman%2C+M+J+B">Max J. Brenner Newman</a>, <a href="/search/astro-ph?searchtype=author&query=Brink%2C+T+G">Thomas G. Brink</a>, <a href="/search/astro-ph?searchtype=author&query=Bustamante-Rosell%2C+M+J">Maria Jose Bustamante-Rosell</a>, <a href="/search/astro-ph?searchtype=author&query=Camacho-Neves%2C+Y">Yssavo Camacho-Neves</a>, <a href="/search/astro-ph?searchtype=author&query=Clocchiatti%2C+A">Alejandro Clocchiatti</a>, <a href="/search/astro-ph?searchtype=author&query=Coulter%2C+D+A">David A. Coulter</a>, <a href="/search/astro-ph?searchtype=author&query=Davis%2C+K+W">Kyle W. Davis</a>, <a href="/search/astro-ph?searchtype=author&query=Deckers%2C+M">Maxime Deckers</a>, <a href="/search/astro-ph?searchtype=author&query=Dimitriadis%2C+G">Georgios Dimitriadis</a> , et al. (56 additional authors not shown) </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2308.12450v2-abstract-short" style="display: inline;"> We present an analysis of ground-based and JWST observations of SN~2022pul, a peculiar "03fg-like" (or "super-Chandrasekhar") Type Ia supernova (SN Ia), in the nebular phase at 338d post explosion. Our combined spectrum continuously covers 0.4--14 $渭$m and includes the first mid-infrared spectrum of an 03fg-like SN Ia. Compared to normal SN Ia 2021aefx, SN 2022pul exhibits a lower mean ionization… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2308.12450v2-abstract-full').style.display = 'inline'; document.getElementById('2308.12450v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2308.12450v2-abstract-full" style="display: none;"> We present an analysis of ground-based and JWST observations of SN~2022pul, a peculiar "03fg-like" (or "super-Chandrasekhar") Type Ia supernova (SN Ia), in the nebular phase at 338d post explosion. Our combined spectrum continuously covers 0.4--14 $渭$m and includes the first mid-infrared spectrum of an 03fg-like SN Ia. Compared to normal SN Ia 2021aefx, SN 2022pul exhibits a lower mean ionization state, asymmetric emission-line profiles, stronger emission from the intermediate-mass elements (IMEs) argon and calcium, weaker emission from iron-group elements (IGEs), and the first unambiguous detection of neon in a SN Ia. Strong, broad, centrally peaked [Ne II] line at 12.81 $渭$m was previously predicted as a hallmark of "violent merger'' SN Ia models, where dynamical interaction between two sub-$M_{ch}$ white dwarfs (WDs) causes disruption of the lower mass WD and detonation of the other. The violent merger scenario was already a leading hypothesis for 03fg-like SNe Ia; in SN 2022pul it can explain the large-scale ejecta asymmetries seen between the IMEs and IGEs and the central location of narrow oxygen and broad neon. We modify extant models to add clumping of the ejecta to better reproduce the optical iron emission, and add mass in the innermost region ($< 2000$ km s$^{-1}$) to account for the observed narrow [O I]~$位\lambda6300$, 6364 emission. A violent WD-WD merger explains many of the observations of SN 2022pul, and our results favor this model interpretation for the subclass of 03fg-like SN Ia. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2308.12450v2-abstract-full').style.display = 'none'; document.getElementById('2308.12450v2-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 23 May, 2024; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 23 August, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> August 2023. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">20 pages, 10 figures, published in ApJ</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> The Astrophysical Journal, Volume 966, Issue 1, id.135, 18 pp., May 2024 </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2308.12449">arXiv:2308.12449</a> <span> [<a href="https://arxiv.org/pdf/2308.12449">pdf</a>, <a href="https://arxiv.org/format/2308.12449">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="High Energy Astrophysical Phenomena">astro-ph.HE</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> </div> </div> <p class="title is-5 mathjax"> Ground-based and JWST Observations of SN 2022pul: I. Unusual Signatures of Carbon, Oxygen, and Circumstellar Interaction in a Peculiar Type Ia Supernova </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Siebert%2C+M+R">Matthew R. Siebert</a>, <a href="/search/astro-ph?searchtype=author&query=Kwok%2C+L+A">Lindsey A. Kwok</a>, <a href="/search/astro-ph?searchtype=author&query=Johansson%2C+J">Joel Johansson</a>, <a href="/search/astro-ph?searchtype=author&query=Jha%2C+S+W">Saurabh W. Jha</a>, <a href="/search/astro-ph?searchtype=author&query=Blondin%2C+S">St茅phane Blondin</a>, <a href="/search/astro-ph?searchtype=author&query=Dessart%2C+L">Luc Dessart</a>, <a href="/search/astro-ph?searchtype=author&query=Foley%2C+R+J">Ryan J. Foley</a>, <a href="/search/astro-ph?searchtype=author&query=Hillier%2C+D+J">D. John Hillier</a>, <a href="/search/astro-ph?searchtype=author&query=Larison%2C+C">Conor Larison</a>, <a href="/search/astro-ph?searchtype=author&query=Pakmor%2C+R">R眉diger Pakmor</a>, <a href="/search/astro-ph?searchtype=author&query=Temim%2C+T">Tea Temim</a>, <a href="/search/astro-ph?searchtype=author&query=Andrews%2C+J+E">Jennifer E. Andrews</a>, <a href="/search/astro-ph?searchtype=author&query=Auchettl%2C+K">Katie Auchettl</a>, <a href="/search/astro-ph?searchtype=author&query=Badenes%2C+C">Carles Badenes</a>, <a href="/search/astro-ph?searchtype=author&query=Barna%2C+B">Barnabas Barna</a>, <a href="/search/astro-ph?searchtype=author&query=Bostroem%2C+K+A">K. Azalee Bostroem</a>, <a href="/search/astro-ph?searchtype=author&query=Newman%2C+M+J+B">Max J. Brenner Newman</a>, <a href="/search/astro-ph?searchtype=author&query=Brink%2C+T+G">Thomas G. Brink</a>, <a href="/search/astro-ph?searchtype=author&query=Bustamante-Rosell%2C+M+J">Mar铆a Jos茅 Bustamante-Rosell</a>, <a href="/search/astro-ph?searchtype=author&query=Camacho-Neves%2C+Y">Yssavo Camacho-Neves</a>, <a href="/search/astro-ph?searchtype=author&query=Clocchiatti%2C+A">Alejandro Clocchiatti</a>, <a href="/search/astro-ph?searchtype=author&query=Coulter%2C+D+A">David A. Coulter</a>, <a href="/search/astro-ph?searchtype=author&query=Davis%2C+K+W">Kyle W. Davis</a>, <a href="/search/astro-ph?searchtype=author&query=Deckers%2C+M">Maxime Deckers</a>, <a href="/search/astro-ph?searchtype=author&query=Dimitriadis%2C+G">Georgios Dimitriadis</a> , et al. (57 additional authors not shown) </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2308.12449v1-abstract-short" style="display: inline;"> Nebular-phase observations of peculiar Type Ia supernovae (SNe Ia) provide important constraints on progenitor scenarios and explosion dynamics for both these rare SNe and the more common, cosmologically useful SNe Ia. We present observations from an extensive ground-based and space-based follow-up campaign to characterize SN 2022pul, a "super-Chandrasekhar" mass SN Ia (alternatively "03fg-like" S… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2308.12449v1-abstract-full').style.display = 'inline'; document.getElementById('2308.12449v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2308.12449v1-abstract-full" style="display: none;"> Nebular-phase observations of peculiar Type Ia supernovae (SNe Ia) provide important constraints on progenitor scenarios and explosion dynamics for both these rare SNe and the more common, cosmologically useful SNe Ia. We present observations from an extensive ground-based and space-based follow-up campaign to characterize SN 2022pul, a "super-Chandrasekhar" mass SN Ia (alternatively "03fg-like" SN), from before peak brightness to well into the nebular phase across optical to mid-infrared (MIR) wavelengths. The early rise of the light curve is atypical, exhibiting two distinct components, consistent with SN Ia ejecta interacting with dense carbon-oxygen rich circumstellar material (CSM). In the optical, SN 2022pul is most similar to SN 2012dn, having a low estimated peak luminosity ($M_{B}=-18.9$ mag) and high photospheric velocity relative to other 03fg-like SNe. In the nebular phase, SN 2022pul adds to the increasing diversity of the 03fg-like subclass. From 168 to 336 days after peak $B$-band brightness, SN 2022pul exhibits asymmetric and narrow emission from [O I] $位位6300,\ 6364$ (${\rm FWHM} \approx 2{,}000$ km s$^{-1}$), strong, broad emission from [Ca II] $位位7291,\ 7323$ (${\rm FWHM} \approx 7{,}300$ km s$^{-1}$), and a rapid Fe III to Fe II ionization change. Finally, we present the first-ever optical-to-mid-infrared (MIR) nebular spectrum of an 03fg-like SN Ia using data from JWST. In the MIR, strong lines of neon and argon, weak emission from stable nickel, and strong thermal dust emission (with $T \approx 500$ K), combined with prominent [O I] in the optical, suggest that SN 2022pul was produced by a white dwarf merger within carbon/oxygen-rich CSM. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2308.12449v1-abstract-full').style.display = 'none'; document.getElementById('2308.12449v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 23 August, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> August 2023. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">23 pages, 11 figures, submitted to ApJ</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2308.06334">arXiv:2308.06334</a> <span> [<a href="https://arxiv.org/pdf/2308.06334">pdf</a>, <a href="https://arxiv.org/format/2308.06334">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="High Energy Astrophysical Phenomena">astro-ph.HE</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> </div> </div> <p class="title is-5 mathjax"> SN 2022joj: A Potential Double Detonation with a Thin Helium shell </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Gonzalez%2C+E+P">E. Padilla Gonzalez</a>, <a href="/search/astro-ph?searchtype=author&query=Howell%2C+D+A">D. A. Howell</a>, <a href="/search/astro-ph?searchtype=author&query=Terreran%2C+G">G. Terreran</a>, <a href="/search/astro-ph?searchtype=author&query=McCully%2C+C">C. McCully</a>, <a href="/search/astro-ph?searchtype=author&query=Newsome%2C+M">M. Newsome</a>, <a href="/search/astro-ph?searchtype=author&query=Burke%2C+J">J. Burke</a>, <a href="/search/astro-ph?searchtype=author&query=Farah%2C+J">J. Farah</a>, <a href="/search/astro-ph?searchtype=author&query=Pellegrino%2C+C">C. Pellegrino</a>, <a href="/search/astro-ph?searchtype=author&query=Bostroem%2C+K+A">K. A. Bostroem</a>, <a href="/search/astro-ph?searchtype=author&query=Hosseinzadeh%2C+G">G. Hosseinzadeh</a>, <a href="/search/astro-ph?searchtype=author&query=Pearson%2C+J">J. Pearson</a>, <a href="/search/astro-ph?searchtype=author&query=Sand%2C+D+J">D. J. Sand</a>, <a href="/search/astro-ph?searchtype=author&query=Shrestha%2C+M">M. Shrestha</a>, <a href="/search/astro-ph?searchtype=author&query=Smith%2C+N">N. Smith</a>, <a href="/search/astro-ph?searchtype=author&query=Dong%2C+Y">Y. Dong</a>, <a href="/search/astro-ph?searchtype=author&query=Retamal%2C+N+M">N. Meza Retamal</a>, <a href="/search/astro-ph?searchtype=author&query=Valenti%2C+S">S. Valenti</a>, <a href="/search/astro-ph?searchtype=author&query=Boos%2C+S">S. Boos</a>, <a href="/search/astro-ph?searchtype=author&query=Shen%2C+K+J">K. J. Shen</a>, <a href="/search/astro-ph?searchtype=author&query=Townsley%2C+D">D. Townsley</a>, <a href="/search/astro-ph?searchtype=author&query=Galbany%2C+L">L. Galbany</a>, <a href="/search/astro-ph?searchtype=author&query=Piscarreta%2C+L">L. Piscarreta</a>, <a href="/search/astro-ph?searchtype=author&query=Foley%2C+R+J">R. J. Foley</a>, <a href="/search/astro-ph?searchtype=author&query=Bustamante-Rosell%2C+M+J">M. J. Bustamante-Rosell</a>, <a href="/search/astro-ph?searchtype=author&query=Coulter%2C+D+A">D. A. Coulter</a> , et al. (12 additional authors not shown) </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2308.06334v1-abstract-short" style="display: inline;"> We present photometric and spectroscopic data for SN 2022joj, a nearby peculiar Type Ia supernova (SN Ia) with a fast decline rate ($\rm{螖m_{15,B}=1.4}$ mag). SN 2022joj shows exceedingly red colors, with a value of approximately ${B-V \approx 1.1}$ mag during its initial stages, beginning from $11$ days before maximum brightness. As it evolves the flux shifts towards the blue end of the spectrum,… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2308.06334v1-abstract-full').style.display = 'inline'; document.getElementById('2308.06334v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2308.06334v1-abstract-full" style="display: none;"> We present photometric and spectroscopic data for SN 2022joj, a nearby peculiar Type Ia supernova (SN Ia) with a fast decline rate ($\rm{螖m_{15,B}=1.4}$ mag). SN 2022joj shows exceedingly red colors, with a value of approximately ${B-V \approx 1.1}$ mag during its initial stages, beginning from $11$ days before maximum brightness. As it evolves the flux shifts towards the blue end of the spectrum, approaching ${B-V \approx 0}$ mag around maximum light. Furthermore, at maximum light and beyond, the photometry is consistent with that of typical SNe Ia. This unusual behavior extends to its spectral characteristics, which initially displayed a red spectrum and later evolved to exhibit greater consistency with typical SNe Ia. We consider two potential explanations for this behavior: double detonation from a helium shell on a sub-Chandrasekhar-mass white dwarf and Chandrasekhar-mass models with a shallow distribution of $\rm{^{56}Ni}$. The shallow nickel models could not reproduce the red colors in the early light curves. Spectroscopically, we find strong agreement between SN 2022joj and double-detonation models with white dwarf masses around 1 $\rm{M_{\odot}}$ and thin He-shell between 0.01 and 0.02 $\rm{M_{\odot}}$. Moreover, the early red colors are explained by line-blanketing absorption from iron-peak elements created by the double detonation scenario in similar mass ranges. However, the nebular spectra composition in SN 2022joj deviates from expectations for double detonation, as we observe strong [Fe III] emission instead of [Ca II] lines as anticipated from double detonation models. More detailed modeling, e.g., including viewing angle effects, is required to test if double detonation models can explain the nebular spectra. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2308.06334v1-abstract-full').style.display = 'none'; document.getElementById('2308.06334v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 11 August, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> August 2023. </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2307.03165">arXiv:2307.03165</a> <span> [<a href="https://arxiv.org/pdf/2307.03165">pdf</a>, <a href="https://arxiv.org/format/2307.03165">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="High Energy Astrophysical Phenomena">astro-ph.HE</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.3847/2041-8213/acf299">10.3847/2041-8213/acf299 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> From Discovery to the First Month of the Type II Supernova 2023ixf: High and Variable Mass Loss in the Final Year before Explosion </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Hiramatsu%2C+D">Daichi Hiramatsu</a>, <a href="/search/astro-ph?searchtype=author&query=Tsuna%2C+D">Daichi Tsuna</a>, <a href="/search/astro-ph?searchtype=author&query=Berger%2C+E">Edo Berger</a>, <a href="/search/astro-ph?searchtype=author&query=Itagaki%2C+K">Koichi Itagaki</a>, <a href="/search/astro-ph?searchtype=author&query=Goldberg%2C+J+A">Jared A. Goldberg</a>, <a href="/search/astro-ph?searchtype=author&query=Gomez%2C+S">Sebastian Gomez</a>, <a href="/search/astro-ph?searchtype=author&query=De%2C+K">Kishalay De</a>, <a href="/search/astro-ph?searchtype=author&query=Hosseinzadeh%2C+G">Griffin Hosseinzadeh</a>, <a href="/search/astro-ph?searchtype=author&query=Bostroem%2C+K+A">K. Azalee Bostroem</a>, <a href="/search/astro-ph?searchtype=author&query=Brown%2C+P+J">Peter J. Brown</a>, <a href="/search/astro-ph?searchtype=author&query=Arcavi%2C+I">Iair Arcavi</a>, <a href="/search/astro-ph?searchtype=author&query=Bieryla%2C+A">Allyson Bieryla</a>, <a href="/search/astro-ph?searchtype=author&query=Blanchard%2C+P+K">Peter K. Blanchard</a>, <a href="/search/astro-ph?searchtype=author&query=Esquerdo%2C+G+A">Gilbert A. Esquerdo</a>, <a href="/search/astro-ph?searchtype=author&query=Farah%2C+J">Joseph Farah</a>, <a href="/search/astro-ph?searchtype=author&query=Howell%2C+D+A">D. Andrew Howell</a>, <a href="/search/astro-ph?searchtype=author&query=Matsumoto%2C+T">Tatsuya Matsumoto</a>, <a href="/search/astro-ph?searchtype=author&query=McCully%2C+C">Curtis McCully</a>, <a href="/search/astro-ph?searchtype=author&query=Newsome%2C+M">Megan Newsome</a>, <a href="/search/astro-ph?searchtype=author&query=Gonzalez%2C+E+P">Estefania Padilla Gonzalez</a>, <a href="/search/astro-ph?searchtype=author&query=Pellegrino%2C+C">Craig Pellegrino</a>, <a href="/search/astro-ph?searchtype=author&query=Rhee%2C+J">Jaehyon Rhee</a>, <a href="/search/astro-ph?searchtype=author&query=Terreran%2C+G">Giacomo Terreran</a>, <a href="/search/astro-ph?searchtype=author&query=Vink%C3%B3%2C+J">J贸zsef Vink贸</a>, <a href="/search/astro-ph?searchtype=author&query=Wheeler%2C+J+C">J. Craig Wheeler</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2307.03165v2-abstract-short" style="display: inline;"> We present the discovery of the Type II supernova SN 2023ixf in M101 and follow-up photometric and spectroscopic observations, respectively, in the first month and week of its evolution. Our discovery was made within a day of estimated first light, and the following light curve is characterized by a rapid rise ($\approx5$ days) to a luminous peak ($M_V\approx-18.2$ mag) and plateau (… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2307.03165v2-abstract-full').style.display = 'inline'; document.getElementById('2307.03165v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2307.03165v2-abstract-full" style="display: none;"> We present the discovery of the Type II supernova SN 2023ixf in M101 and follow-up photometric and spectroscopic observations, respectively, in the first month and week of its evolution. Our discovery was made within a day of estimated first light, and the following light curve is characterized by a rapid rise ($\approx5$ days) to a luminous peak ($M_V\approx-18.2$ mag) and plateau ($M_V\approx-17.6$ mag) extending to $30$ days with a fast decline rate of $\approx0.03$ mag day$^{-1}$. During the rising phase, $U-V$ color shows blueward evolution, followed by redward evolution in the plateau phase. Prominent flash features of hydrogen, helium, carbon, and nitrogen dominate the spectra up to $\approx5$ days after first light, with a transition to a higher ionization state in the first $\approx2$ days. Both the $U-V$ color and flash ionization states suggest a rise in the temperature, indicative of a delayed shock breakout inside dense circumstellar material (CSM). From the timescales of CSM interaction, we estimate its compact radial extent of $\sim(3-7)\times10^{14}$ cm. We then construct numerical light-curve models based on both continuous and eruptive mass-loss scenarios shortly before explosion. For the continuous mass-loss scenario, we infer a range of mass-loss history with $0.1-1.0\,M_\odot\,{\rm yr}^{-1}$ in the final $2-1$ yr before explosion, with a potentially decreasing mass loss of $0.01-0.1\,M_\odot\,{\rm yr}^{-1}$ in $\sim0.7-0.4$ yr toward the explosion. For the eruptive mass-loss scenario, we favor eruptions releasing $0.3-1\,M_\odot$ of the envelope at about a year before explosion, which result in CSM with mass and extent similar to the continuous scenario. We discuss the implications of the available multiwavelength constraints obtained thus far on the progenitor candidate and SN 2023ixf to our variable CSM models. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2307.03165v2-abstract-full').style.display = 'none'; document.getElementById('2307.03165v2-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 20 September, 2023; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 6 July, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> July 2023. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">Updated to match the published letter in ApJL, 2023 September 19</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> The Astrophysical Journal Letters, 955:L8 (13pp), 2023 September 20 </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2307.02539">arXiv:2307.02539</a> <span> [<a href="https://arxiv.org/pdf/2307.02539">pdf</a>, <a href="https://arxiv.org/format/2307.02539">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="High Energy Astrophysical Phenomena">astro-ph.HE</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> </div> </div> <p class="title is-5 mathjax"> A comprehensive optical search for pre-explosion outbursts from the quiescent progenitor of SN~2023ixf </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Dong%2C+Y">Yize Dong</a>, <a href="/search/astro-ph?searchtype=author&query=Sand%2C+D+J">David J. Sand</a>, <a href="/search/astro-ph?searchtype=author&query=Valenti%2C+S">Stefano Valenti</a>, <a href="/search/astro-ph?searchtype=author&query=Bostroem%2C+K+A">K. Azalee Bostroem</a>, <a href="/search/astro-ph?searchtype=author&query=Andrews%2C+J+E">Jennifer E. Andrews</a>, <a href="/search/astro-ph?searchtype=author&query=Hosseinzadeh%2C+G">Griffin Hosseinzadeh</a>, <a href="/search/astro-ph?searchtype=author&query=Hoang%2C+E">Emily Hoang</a>, <a href="/search/astro-ph?searchtype=author&query=Janzen%2C+D">Daryl Janzen</a>, <a href="/search/astro-ph?searchtype=author&query=Jencson%2C+J+E">Jacob E. Jencson</a>, <a href="/search/astro-ph?searchtype=author&query=Lundquist%2C+M">Michael Lundquist</a>, <a href="/search/astro-ph?searchtype=author&query=Retamal%2C+N+E+M">Nicolas E. Meza Retamal</a>, <a href="/search/astro-ph?searchtype=author&query=Pearson%2C+J">Jeniveve Pearson</a>, <a href="/search/astro-ph?searchtype=author&query=Shrestha%2C+M">Manisha Shrestha</a>, <a href="/search/astro-ph?searchtype=author&query=Haislip%2C+J">Joshua Haislip</a>, <a href="/search/astro-ph?searchtype=author&query=Kouprianov%2C+V">Vladimir Kouprianov</a>, <a href="/search/astro-ph?searchtype=author&query=Reichart%2C+D+E">Daniel E. Reichart</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2307.02539v1-abstract-short" style="display: inline;"> We perform a comprehensive search for optical precursor emission at the position of SN~2023ixf using data from the DLT40, ZTF and ATLAS surveys. By comparing the current data set with precursor outburst hydrodynamical model light curves, we find that the probability of a significant outburst within five years of explosion is low, and the circumstellar material (CSM) ejected during any possible pre… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2307.02539v1-abstract-full').style.display = 'inline'; document.getElementById('2307.02539v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2307.02539v1-abstract-full" style="display: none;"> We perform a comprehensive search for optical precursor emission at the position of SN~2023ixf using data from the DLT40, ZTF and ATLAS surveys. By comparing the current data set with precursor outburst hydrodynamical model light curves, we find that the probability of a significant outburst within five years of explosion is low, and the circumstellar material (CSM) ejected during any possible precursor outburst is likely smaller than $\sim$0.015\msun. By comparing to a set of toy models, we find that, if there was a precursor outburst, the duration must have been shorter than $\sim$100 days for a typical brightness of $M_{r}\simeq-9$ mag or shorter than 200 days for $M_{r}\simeq-8$ mag; brighter, longer outbursts would have been discovered. Precursor activity like that observed in the normal type II SN~2020tlf ($M_{r}\simeq-11.5$) can be excluded in SN~2023ixf. If the dense CSM inferred by early flash spectroscopy and other studies is related to one or more precursor outbursts, then our observations indicate that any such outburst would have to be faint and only last for days to months, or it occurred more than five years prior to the explosion. Alternatively, any dense, confined CSM may not be due to eruptive mass loss from a single red supergiant (RSG) progenitor. Taken together, the results of SN~2023ixf and SN~2020tlf indicate that there may be more than one physical mechanism behind the dense CSM inferred around some normal type II SNe. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2307.02539v1-abstract-full').style.display = 'none'; document.getElementById('2307.02539v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 5 July, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> July 2023. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">10 pages, 4 figures</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2306.10119">arXiv:2306.10119</a> <span> [<a href="https://arxiv.org/pdf/2306.10119">pdf</a>, <a href="https://arxiv.org/format/2306.10119">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="High Energy Astrophysical Phenomena">astro-ph.HE</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.3847/2041-8213/acf9a4">10.3847/2041-8213/acf9a4 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Early Spectroscopy and Dense Circumstellar Medium Interaction in SN 2023ixf </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Bostroem%2C+K+A">K. Azalee Bostroem</a>, <a href="/search/astro-ph?searchtype=author&query=Pearson%2C+J">Jeniveve Pearson</a>, <a href="/search/astro-ph?searchtype=author&query=Shrestha%2C+M">Manisha Shrestha</a>, <a href="/search/astro-ph?searchtype=author&query=Sand%2C+D+J">David J. Sand</a>, <a href="/search/astro-ph?searchtype=author&query=Valenti%2C+S">Stefano Valenti</a>, <a href="/search/astro-ph?searchtype=author&query=Jha%2C+S+W">Saurabh W. Jha</a>, <a href="/search/astro-ph?searchtype=author&query=Andrews%2C+J+E">Jennifer E. Andrews</a>, <a href="/search/astro-ph?searchtype=author&query=Smith%2C+N">Nathan Smith</a>, <a href="/search/astro-ph?searchtype=author&query=Terreran%2C+G">Giacomo Terreran</a>, <a href="/search/astro-ph?searchtype=author&query=Green%2C+E">Elizabeth Green</a>, <a href="/search/astro-ph?searchtype=author&query=Dong%2C+Y">Yize Dong</a>, <a href="/search/astro-ph?searchtype=author&query=Lundquist%2C+M">Michael Lundquist</a>, <a href="/search/astro-ph?searchtype=author&query=Haislip%2C+J">Joshua Haislip</a>, <a href="/search/astro-ph?searchtype=author&query=Hoang%2C+E+T">Emily T. Hoang</a>, <a href="/search/astro-ph?searchtype=author&query=Hosseinzadeh%2C+G">Griffin Hosseinzadeh</a>, <a href="/search/astro-ph?searchtype=author&query=Janzen%2C+D">Daryl Janzen</a>, <a href="/search/astro-ph?searchtype=author&query=Jencson%2C+J+E">Jacob E. Jencson</a>, <a href="/search/astro-ph?searchtype=author&query=Kouprianov%2C+V">Vladimir Kouprianov</a>, <a href="/search/astro-ph?searchtype=author&query=Paraskeva%2C+E">Emmy Paraskeva</a>, <a href="/search/astro-ph?searchtype=author&query=Retamal%2C+N+E+M">Nicolas E. Meza Retamal</a>, <a href="/search/astro-ph?searchtype=author&query=Reichart%2C+D+E">Daniel E. Reichart</a>, <a href="/search/astro-ph?searchtype=author&query=Arcavi%2C+I">Iair Arcavi</a>, <a href="/search/astro-ph?searchtype=author&query=Bonanos%2C+A+Z">Alceste Z. Bonanos</a>, <a href="/search/astro-ph?searchtype=author&query=Coughlin%2C+M+W">Michael W. Coughlin</a>, <a href="/search/astro-ph?searchtype=author&query=Dobson%2C+R">Ross Dobson</a> , et al. (31 additional authors not shown) </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2306.10119v2-abstract-short" style="display: inline;"> We present the optical spectroscopic evolution of SN~2023ixf seen in sub-night cadence spectra from 1.18 to 14 days after explosion. We identify high-ionization emission features, signatures of interaction with material surrounding the progenitor star, that fade over the first 7 days, with rapid evolution between spectra observed within the same night. We compare the emission lines present and the… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2306.10119v2-abstract-full').style.display = 'inline'; document.getElementById('2306.10119v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2306.10119v2-abstract-full" style="display: none;"> We present the optical spectroscopic evolution of SN~2023ixf seen in sub-night cadence spectra from 1.18 to 14 days after explosion. We identify high-ionization emission features, signatures of interaction with material surrounding the progenitor star, that fade over the first 7 days, with rapid evolution between spectra observed within the same night. We compare the emission lines present and their relative strength to those of other supernovae with early interaction, finding a close match to SN~2020pni and SN~2017ahn in the first spectrum and SN~2014G at later epochs. To physically interpret our observations we compare them to CMFGEN models with confined, dense circumstellar material around a red supergiant progenitor from the literature. We find that very few models reproduce the blended \NC{} emission lines observed in the first few spectra and their rapid disappearance thereafter, making this a unique diagnostic. From the best models, we find a mass-loss rate of $10^{-3}-10^{-2}$ \mlunit{}, which far exceeds the mass-loss rate for any steady wind, especially for a red supergiant in the initial mass range of the detected progenitor. These mass-loss rates are, however, similar to rates inferred for other supernovae with early circumstellar interaction. Using the phase when the narrow emission features disappear, we calculate an outer dense radius of circumstellar material $R_\mathrm{CSM, out}\sim5\times10^{14}~\mathrm{cm}$ and a mean circumstellar material density of $蟻=5.6\times10^{-14}~\mathrm{g\,cm^{-3}}$. This is consistent with the lower limit on the outer radius of the circumstellar material we calculate from the peak \Halpha{} emission flux, $R_\text{CSM, out}\gtrsim9\times10^{13}~\mathrm{cm}$. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2306.10119v2-abstract-full').style.display = 'none'; document.getElementById('2306.10119v2-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 12 December, 2023; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 16 June, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> June 2023. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">Published in ApJL</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> The Astrophysical Journal Letters, Volume 956, Issue 1, id.L5, 17 pp., Oct 2023 </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2306.08678">arXiv:2306.08678</a> <span> [<a href="https://arxiv.org/pdf/2306.08678">pdf</a>, <a href="https://arxiv.org/format/2306.08678">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Astrophysics of Galaxies">astro-ph.GA</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="High Energy Astrophysical Phenomena">astro-ph.HE</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.3847/2041-8213/ace618">10.3847/2041-8213/ace618 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> A Luminous Red Supergiant and Dusty Long-period Variable Progenitor for SN 2023ixf </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Jencson%2C+J+E">Jacob E. Jencson</a>, <a href="/search/astro-ph?searchtype=author&query=Pearson%2C+J">Jeniveve Pearson</a>, <a href="/search/astro-ph?searchtype=author&query=Beasor%2C+E+R">Emma R. Beasor</a>, <a href="/search/astro-ph?searchtype=author&query=Lau%2C+R+M">Ryan M. Lau</a>, <a href="/search/astro-ph?searchtype=author&query=Andrews%2C+J+E">Jennifer E. Andrews</a>, <a href="/search/astro-ph?searchtype=author&query=Bostroem%2C+K+A">K. Azalee Bostroem</a>, <a href="/search/astro-ph?searchtype=author&query=Dong%2C+Y">Yize Dong</a>, <a href="/search/astro-ph?searchtype=author&query=Engesser%2C+M">Michael Engesser</a>, <a href="/search/astro-ph?searchtype=author&query=Gomez%2C+S">Sebastian Gomez</a>, <a href="/search/astro-ph?searchtype=author&query=Guolo%2C+M">Muryel Guolo</a>, <a href="/search/astro-ph?searchtype=author&query=Hoang%2C+E">Emily Hoang</a>, <a href="/search/astro-ph?searchtype=author&query=Hosseinzadeh%2C+G">Griffin Hosseinzadeh</a>, <a href="/search/astro-ph?searchtype=author&query=Jha%2C+S+W">Saurabh W. Jha</a>, <a href="/search/astro-ph?searchtype=author&query=Karambelkar%2C+V">Viraj Karambelkar</a>, <a href="/search/astro-ph?searchtype=author&query=Kasliwal%2C+M+M">Mansi M. Kasliwal</a>, <a href="/search/astro-ph?searchtype=author&query=Lundquist%2C+M">Michael Lundquist</a>, <a href="/search/astro-ph?searchtype=author&query=Retamal%2C+N+E+M">Nicolas E. Meza Retamal</a>, <a href="/search/astro-ph?searchtype=author&query=Rest%2C+A">Armin Rest</a>, <a href="/search/astro-ph?searchtype=author&query=Sand%2C+D+J">David J. Sand</a>, <a href="/search/astro-ph?searchtype=author&query=Shahbandeh%2C+M">Melissa Shahbandeh</a>, <a href="/search/astro-ph?searchtype=author&query=Shrestha%2C+M">Manisha Shrestha</a>, <a href="/search/astro-ph?searchtype=author&query=Smith%2C+N">Nathan Smith</a>, <a href="/search/astro-ph?searchtype=author&query=Strader%2C+J">Jay Strader</a>, <a href="/search/astro-ph?searchtype=author&query=Valenti%2C+S">Stefano Valenti</a>, <a href="/search/astro-ph?searchtype=author&query=Wang%2C+Q">Qinan Wang</a> , et al. (1 additional authors not shown) </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2306.08678v2-abstract-short" style="display: inline;"> We analyze pre-explosion near- and mid-infrared (IR) imaging of the site of SN 2023ixf in the nearby spiral galaxy M101 and characterize the candidate progenitor star. The star displays compelling evidence of variability with a possible period of $\approx$1000 days and an amplitude of $螖m \approx 0.6$ mag in extensive monitoring with the Spitzer Space Telescope since 2004, likely indicative of rad… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2306.08678v2-abstract-full').style.display = 'inline'; document.getElementById('2306.08678v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2306.08678v2-abstract-full" style="display: none;"> We analyze pre-explosion near- and mid-infrared (IR) imaging of the site of SN 2023ixf in the nearby spiral galaxy M101 and characterize the candidate progenitor star. The star displays compelling evidence of variability with a possible period of $\approx$1000 days and an amplitude of $螖m \approx 0.6$ mag in extensive monitoring with the Spitzer Space Telescope since 2004, likely indicative of radial pulsations. Variability consistent with this period is also seen in the near-IR $J$ and $K_{s}$ bands between 2010 and 2023, up to just 10 days before the explosion. Beyond the periodic variability, we do not find evidence for any IR-bright pre-supernova outbursts in this time period. The IR brightness ($M_{K_s} = -10.7$ mag) and color ($J-K_{s} = 1.6$ mag) of the star suggest a luminous and dusty red supergiant. Modeling of the phase-averaged spectral energy distribution (SED) yields constraints on the stellar temperature ($T_{\mathrm{eff}} = 3500_{-1400}^{+800}$ K) and luminosity ($\log L/L_{\odot} = 5.1\pm0.2$). This places the candidate among the most luminous Type II supernova progenitors with direct imaging constraints, with the caveat that many of these rely only on optical measurements. Comparison with stellar evolution models gives an initial mass of $M_{\mathrm{init}} = 17\pm4 M_{\odot}$. We estimate the pre-supernova mass-loss rate of the star between 3 and 19 yr before explosion from the SED modeling at $\dot M \approx 3\times10^{-5}$ to $3\times10^{-4} M_{\odot}$ yr$^{-1}$ for an assumed wind velocity of $v_w = 10$ km s$^{-1}$, perhaps pointing to enhanced mass loss in a pulsation-driven wind. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2306.08678v2-abstract-full').style.display = 'none'; document.getElementById('2306.08678v2-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 1 August, 2023; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 14 June, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> June 2023. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">13 pages, 5 figures, published in ApJL, replacement with revisions to match published version</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> ApJL 952 (2023) L30 </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2306.07964">arXiv:2306.07964</a> <span> [<a href="https://arxiv.org/pdf/2306.07964">pdf</a>, <a href="https://arxiv.org/format/2306.07964">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="High Energy Astrophysical Phenomena">astro-ph.HE</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> </div> </div> <p class="title is-5 mathjax"> High resolution spectroscopy of SN~2023ixf's first week: Engulfing the Asymmetric Circumstellar Material </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Smith%2C+N">Nathan Smith</a>, <a href="/search/astro-ph?searchtype=author&query=Pearson%2C+J">Jeniveve Pearson</a>, <a href="/search/astro-ph?searchtype=author&query=Sand%2C+D+J">David J. Sand</a>, <a href="/search/astro-ph?searchtype=author&query=Ilyin%2C+I">Ilya Ilyin</a>, <a href="/search/astro-ph?searchtype=author&query=Bostroem%2C+K+A">K. Azalee Bostroem</a>, <a href="/search/astro-ph?searchtype=author&query=Hosseinzadeh%2C+G">Griffin Hosseinzadeh</a>, <a href="/search/astro-ph?searchtype=author&query=Shrestha%2C+M">Manisha Shrestha</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2306.07964v2-abstract-short" style="display: inline;"> We present a series of high-resolution echelle spectra of SN~2023ixf in M101, obtained nightly during the first week or so after discovery using PEPSI on the LBT. NaID absorption in these spectra indicates a host reddening of $E(B-V)$=0.031~mag and a systemic velocity of $+$7~km~s$^{-1}$ relative to the average redshift of M101. Dramatic changes are seen in in the strength and shape of strong emis… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2306.07964v2-abstract-full').style.display = 'inline'; document.getElementById('2306.07964v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2306.07964v2-abstract-full" style="display: none;"> We present a series of high-resolution echelle spectra of SN~2023ixf in M101, obtained nightly during the first week or so after discovery using PEPSI on the LBT. NaID absorption in these spectra indicates a host reddening of $E(B-V)$=0.031~mag and a systemic velocity of $+$7~km~s$^{-1}$ relative to the average redshift of M101. Dramatic changes are seen in in the strength and shape of strong emission lines emitted by CSM, including HeII4686, CIV5801,5811, H$伪$, and NIV7109,7123. In general, these narrow lines broaden to become intermediate-width lines before disappearing from the spectrum within a few days, indicating a limited extent to the dense CSM of around 20-30 AU (or $\la$10$^{14.7}$ cm). H$伪$ persists in the spectrum for about a week as an intermediate-width emission line with P~Cyg absorption at 700-1300 km s$^{-1}$ arising in the post-shock shell of swept-up CSM. Early narrow emission lines are blueshifted and indicate an expansion speed in the pre-shock CSM of about 115 km s$^{-1}$, but with even broader emission in higher ionization lines. This is faster than the normal winds of red supergiants, suggesting some mode of eruptive mass loss from the progenitor or radiative acceleration of the CSM. A lack of narrow blueshifted absorption suggests that most of the CSM is not along our line of sight. This and several other clues indicate that the CSM of SN~2023ixf is significantly aspherical. We find that CSM lines disappear after a few days because the asymmetric CSM is engulfed by the SN photosphere. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2306.07964v2-abstract-full').style.display = 'none'; document.getElementById('2306.07964v2-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 18 August, 2023; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 13 June, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> June 2023. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">Accepted verion, 8/14</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2306.06097">arXiv:2306.06097</a> <span> [<a href="https://arxiv.org/pdf/2306.06097">pdf</a>, <a href="https://arxiv.org/format/2306.06097">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="High Energy Astrophysical Phenomena">astro-ph.HE</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.3847/2041-8213/ace4c4">10.3847/2041-8213/ace4c4 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Shock Cooling and Possible Precursor Emission in the Early Light Curve of the Type II SN 2023ixf </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Hosseinzadeh%2C+G">Griffin Hosseinzadeh</a>, <a href="/search/astro-ph?searchtype=author&query=Farah%2C+J">Joseph Farah</a>, <a href="/search/astro-ph?searchtype=author&query=Shrestha%2C+M">Manisha Shrestha</a>, <a href="/search/astro-ph?searchtype=author&query=Sand%2C+D+J">David J. Sand</a>, <a href="/search/astro-ph?searchtype=author&query=Dong%2C+Y">Yize Dong</a>, <a href="/search/astro-ph?searchtype=author&query=Brown%2C+P+J">Peter J. Brown</a>, <a href="/search/astro-ph?searchtype=author&query=Bostroem%2C+K+A">K. Azalee Bostroem</a>, <a href="/search/astro-ph?searchtype=author&query=Valenti%2C+S">Stefano Valenti</a>, <a href="/search/astro-ph?searchtype=author&query=Jha%2C+S+W">Saurabh W. Jha</a>, <a href="/search/astro-ph?searchtype=author&query=Andrews%2C+J+E">Jennifer E. Andrews</a>, <a href="/search/astro-ph?searchtype=author&query=Arcavi%2C+I">Iair Arcavi</a>, <a href="/search/astro-ph?searchtype=author&query=Haislip%2C+J">Joshua Haislip</a>, <a href="/search/astro-ph?searchtype=author&query=Hiramatsu%2C+D">Daichi Hiramatsu</a>, <a href="/search/astro-ph?searchtype=author&query=Hoang%2C+E">Emily Hoang</a>, <a href="/search/astro-ph?searchtype=author&query=Howell%2C+D+A">D. Andrew Howell</a>, <a href="/search/astro-ph?searchtype=author&query=Janzen%2C+D">Daryl Janzen</a>, <a href="/search/astro-ph?searchtype=author&query=Jencson%2C+J+E">Jacob E. Jencson</a>, <a href="/search/astro-ph?searchtype=author&query=Kouprianov%2C+V">Vladimir Kouprianov</a>, <a href="/search/astro-ph?searchtype=author&query=Lundquist%2C+M">Michael Lundquist</a>, <a href="/search/astro-ph?searchtype=author&query=McCully%2C+C">Curtis McCully</a>, <a href="/search/astro-ph?searchtype=author&query=Retamal%2C+N+E+M">Nicolas E. Meza Retamal</a>, <a href="/search/astro-ph?searchtype=author&query=Modjaz%2C+M">Maryam Modjaz</a>, <a href="/search/astro-ph?searchtype=author&query=Newsome%2C+M">Megan Newsome</a>, <a href="/search/astro-ph?searchtype=author&query=Gonzalez%2C+E+P">Estefania Padilla Gonzalez</a>, <a href="/search/astro-ph?searchtype=author&query=Pearson%2C+J">Jeniveve Pearson</a> , et al. (6 additional authors not shown) </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2306.06097v4-abstract-short" style="display: inline;"> We present the densely sampled early light curve of the Type II supernova (SN) 2023ixf, first observed within hours of explosion in the nearby Pinwheel Galaxy (Messier 101; 6.7 Mpc). Comparing these data to recently updated models of shock-cooling emission, we find that the progenitor likely had a radius of $410 \pm 10\ R_\odot$. Our estimate is model dependent but consistent with a red supergiant… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2306.06097v4-abstract-full').style.display = 'inline'; document.getElementById('2306.06097v4-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2306.06097v4-abstract-full" style="display: none;"> We present the densely sampled early light curve of the Type II supernova (SN) 2023ixf, first observed within hours of explosion in the nearby Pinwheel Galaxy (Messier 101; 6.7 Mpc). Comparing these data to recently updated models of shock-cooling emission, we find that the progenitor likely had a radius of $410 \pm 10\ R_\odot$. Our estimate is model dependent but consistent with a red supergiant. These models provide a good fit to the data starting about 1 day after the explosion, despite the fact that the classification spectrum shows signatures of circumstellar material around SN 2023ixf during that time. Photometry during the first day after the explosion, provided almost entirely by amateur astronomers, does not agree with the shock-cooling models or a simple power-law rise fit to data after 1 day. We consider the possible causes of this discrepancy, including precursor activity from the progenitor star, circumstellar interaction, and emission from the shock before or after it breaks out of the stellar surface. The very low luminosity ($-11\mathrm{\ mag} > M > -14\mathrm{\ mag}$) and short duration of the initial excess lead us to prefer a scenario related to prolonged emission from the SN shock traveling through the progenitor system. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2306.06097v4-abstract-full').style.display = 'none'; document.getElementById('2306.06097v4-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 25 August, 2023; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 9 June, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> June 2023. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">updated to match accepted version</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> The Astrophysical Journal Letters, 953:L16 (9pp), 2023 August 10 </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2305.12713">arXiv:2305.12713</a> <span> [<a href="https://arxiv.org/pdf/2305.12713">pdf</a>, <a href="https://arxiv.org/format/2305.12713">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="High Energy Astrophysical Phenomena">astro-ph.HE</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.3847/1538-4357/acd559">10.3847/1538-4357/acd559 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Observational properties of a bright type Iax SN 2018cni and a faint type Iax SN 2020kyg </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Singh%2C+M">Mridweeka Singh</a>, <a href="/search/astro-ph?searchtype=author&query=Sahu%2C+D+K">Devendra. K. Sahu</a>, <a href="/search/astro-ph?searchtype=author&query=Dastidar%2C+R">Raya Dastidar</a>, <a href="/search/astro-ph?searchtype=author&query=Barna%2C+B">Barnabas Barna</a>, <a href="/search/astro-ph?searchtype=author&query=Misra%2C+K">Kuntal Misra</a>, <a href="/search/astro-ph?searchtype=author&query=Gangopadhyay%2C+A">Anjasha Gangopadhyay</a>, <a href="/search/astro-ph?searchtype=author&query=Howell%2C+D+A">D. Andrew Howell</a>, <a href="/search/astro-ph?searchtype=author&query=Jha%2C+S+W">Saurabh W. Jha</a>, <a href="/search/astro-ph?searchtype=author&query=Im%2C+H">Hyobin Im</a>, <a href="/search/astro-ph?searchtype=author&query=Taggart%2C+K">Kirsty Taggart</a>, <a href="/search/astro-ph?searchtype=author&query=Andrews%2C+J">Jennifer Andrews</a>, <a href="/search/astro-ph?searchtype=author&query=Hiramatsu%2C+D">Daichi Hiramatsu</a>, <a href="/search/astro-ph?searchtype=author&query=Teja%2C+R+S">Rishabh Singh Teja</a>, <a href="/search/astro-ph?searchtype=author&query=Pellegrino%2C+C">Craig Pellegrino</a>, <a href="/search/astro-ph?searchtype=author&query=Foley%2C+R+J">Ryan J. Foley</a>, <a href="/search/astro-ph?searchtype=author&query=Joshi%2C+A">Arti Joshi</a>, <a href="/search/astro-ph?searchtype=author&query=Anupama%2C+G+C">G. C. Anupama</a>, <a href="/search/astro-ph?searchtype=author&query=Bostroem%2C+K+A">K. Azalee Bostroem</a>, <a href="/search/astro-ph?searchtype=author&query=Burke%2C+J">Jamison Burke</a>, <a href="/search/astro-ph?searchtype=author&query=Camacho-Neves%2C+Y">Yssavo Camacho-Neves</a>, <a href="/search/astro-ph?searchtype=author&query=Dutta%2C+A">Anirban Dutta</a>, <a href="/search/astro-ph?searchtype=author&query=Kwok%2C+L+A">Lindsey A. Kwok</a>, <a href="/search/astro-ph?searchtype=author&query=McCully%2C+C">Curtis McCully</a>, <a href="/search/astro-ph?searchtype=author&query=Pan%2C+Y">Yen-Chen Pan</a>, <a href="/search/astro-ph?searchtype=author&query=Siebert%2C+M">Matt Siebert</a> , et al. (7 additional authors not shown) </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2305.12713v1-abstract-short" style="display: inline;"> We present the optical photometric and spectroscopic analysis of two type Iax SNe 2018cni and 2020kyg. SN 2018cni is a bright type Iax SN (M$_{V,peak}$ = $-$17.81$\pm$0.21 mag) whereas SN 2020kyg (M$_{V,peak}$ = $-$14.52$\pm$0.21 mag) is a faint one. We derive $^{56}$Ni mass of 0.07 and 0.002 M${_\odot}$, ejecta mass of 0.48 and 0.14 M${_\odot}$ for SNe 2018cni and 2020kyg, respectively. A combine… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2305.12713v1-abstract-full').style.display = 'inline'; document.getElementById('2305.12713v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2305.12713v1-abstract-full" style="display: none;"> We present the optical photometric and spectroscopic analysis of two type Iax SNe 2018cni and 2020kyg. SN 2018cni is a bright type Iax SN (M$_{V,peak}$ = $-$17.81$\pm$0.21 mag) whereas SN 2020kyg (M$_{V,peak}$ = $-$14.52$\pm$0.21 mag) is a faint one. We derive $^{56}$Ni mass of 0.07 and 0.002 M${_\odot}$, ejecta mass of 0.48 and 0.14 M${_\odot}$ for SNe 2018cni and 2020kyg, respectively. A combined study of the bright and faint type Iax SNe in $R/r$- band reveals that the brighter objects tend to have a longer rise time. However, the correlation between the peak luminosity and decline rate shows that bright and faint type Iax SNe exhibit distinct behaviour. Comparison with standard deflagration models suggests that SN 2018cni is consistent with the deflagration of a CO white dwarf whereas the properties of SN 2020kyg can be better explained by the deflagration of a hybrid CONe white dwarf. The spectral features of both the SNe point to the presence of similar chemical species but with different mass fractions. Our spectral modelling indicates stratification at the outer layers and mixed inner ejecta for both the SNe. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2305.12713v1-abstract-full').style.display = 'none'; document.getElementById('2305.12713v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 22 May, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> May 2023. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">18 pages, 18 figures, Accepted for Publication in The Astrophysical Journal</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2305.11168">arXiv:2305.11168</a> <span> [<a href="https://arxiv.org/pdf/2305.11168">pdf</a>, <a href="https://arxiv.org/format/2305.11168">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="High Energy Astrophysical Phenomena">astro-ph.HE</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.3847/1538-4357/ad2854">10.3847/1538-4357/ad2854 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Multiple Peaks and a Long Precursor in the Type IIn Supernova 2021qqp: An Energetic Explosion in a Complex Circumstellar Environment </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Hiramatsu%2C+D">Daichi Hiramatsu</a>, <a href="/search/astro-ph?searchtype=author&query=Matsumoto%2C+T">Tatsuya Matsumoto</a>, <a href="/search/astro-ph?searchtype=author&query=Berger%2C+E">Edo Berger</a>, <a href="/search/astro-ph?searchtype=author&query=Ransome%2C+C">Conor Ransome</a>, <a href="/search/astro-ph?searchtype=author&query=Villar%2C+V+A">V. Ashley Villar</a>, <a href="/search/astro-ph?searchtype=author&query=Gomez%2C+S">Sebastian Gomez</a>, <a href="/search/astro-ph?searchtype=author&query=Cendes%2C+Y">Yvette Cendes</a>, <a href="/search/astro-ph?searchtype=author&query=De%2C+K">Kishalay De</a>, <a href="/search/astro-ph?searchtype=author&query=Bostroem%2C+K+A">K. Azalee Bostroem</a>, <a href="/search/astro-ph?searchtype=author&query=Farah%2C+J">Joseph Farah</a>, <a href="/search/astro-ph?searchtype=author&query=Howell%2C+D+A">D. Andrew Howell</a>, <a href="/search/astro-ph?searchtype=author&query=McCully%2C+C">Curtis McCully</a>, <a href="/search/astro-ph?searchtype=author&query=Newsome%2C+M">Megan Newsome</a>, <a href="/search/astro-ph?searchtype=author&query=Gonzalez%2C+E+P">Estefania Padilla Gonzalez</a>, <a href="/search/astro-ph?searchtype=author&query=Pellegrino%2C+C">Craig Pellegrino</a>, <a href="/search/astro-ph?searchtype=author&query=Suzuki%2C+A">Akihiro Suzuki</a>, <a href="/search/astro-ph?searchtype=author&query=Terreran%2C+G">Giacomo Terreran</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2305.11168v2-abstract-short" style="display: inline;"> We present optical photometry and spectroscopy of the Type IIn supernova (SN) 2021qqp. Its unusual light curve is marked by a long precursor for $\approx300$ days, a rapid increase in brightness for $\approx60$ days, and then a sharp increase of $\approx1.6$ mag in only a few days to a first peak of $M_r \approx -19.5$ mag. The light curve then declines rapidly until it re-brightens to a second di… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2305.11168v2-abstract-full').style.display = 'inline'; document.getElementById('2305.11168v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2305.11168v2-abstract-full" style="display: none;"> We present optical photometry and spectroscopy of the Type IIn supernova (SN) 2021qqp. Its unusual light curve is marked by a long precursor for $\approx300$ days, a rapid increase in brightness for $\approx60$ days, and then a sharp increase of $\approx1.6$ mag in only a few days to a first peak of $M_r \approx -19.5$ mag. The light curve then declines rapidly until it re-brightens to a second distinct peak of $M_r \approx -17.3$ mag centered at $\approx335$ days after the first peak. The spectra are dominated by Balmer lines with a complex morphology, including a narrow component with a width of $\approx 1300$ km s$^{-1}$ (first peak) and $\approx 2500$ km s$^{-1}$ (second peak) that we associate with the circumstellar medium (CSM) and a P Cygni component with an absorption velocity of $\approx 8500$ km s$^{-1}$ (first peak) and $\approx 5600$ km s$^{-1}$ (second peak) that we associate with the SN-CSM interaction shell. Using the luminosity and velocity evolution, we construct a flexible analytical model, finding two significant mass-loss episodes with peak mass loss rates of $\approx 10$ and $\approx 5\,M_{\odot}$ yr$^{-1}$ about $0.8$ and $2$ yr before explosion, respectively, with a total CSM mass of $\approx 2-4\,M_{\odot}$. We show that the most recent mass-loss episode could explain the precursor for the year preceding the explosion. The SN ejecta mass is constrained to be $\approx 5-30\,M_{\odot}$ for an explosion energy of $\approx (3-10)\times10^{51}$ erg. We discuss eruptive massive stars (luminous blue variable, pulsational pair instability) and an extreme stellar merger with a compact object as possible progenitor channels. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2305.11168v2-abstract-full').style.display = 'none'; document.getElementById('2305.11168v2-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 2 April, 2024; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 18 May, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> May 2023. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">Updated to match the published article in ApJ, 2024 March 29</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> The Astrophysical Journal, 964:181 (16pp), 2024 April 1 </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2305.05015">arXiv:2305.05015</a> <span> [<a href="https://arxiv.org/pdf/2305.05015">pdf</a>, <a href="https://arxiv.org/format/2305.05015">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="High Energy Astrophysical Phenomena">astro-ph.HE</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> </div> </div> <p class="title is-5 mathjax"> A Low-Mass Helium Star Progenitor Model for the Type Ibn SN 2020nxt </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Wang%2C+Q">Qinan Wang</a>, <a href="/search/astro-ph?searchtype=author&query=Goel%2C+A">Anika Goel</a>, <a href="/search/astro-ph?searchtype=author&query=Dessart%2C+L">Luc Dessart</a>, <a href="/search/astro-ph?searchtype=author&query=Fox%2C+O+D">Ori D. Fox</a>, <a href="/search/astro-ph?searchtype=author&query=Shahbandeh%2C+M">Melissa Shahbandeh</a>, <a href="/search/astro-ph?searchtype=author&query=Rest%2C+S">Sofia Rest</a>, <a href="/search/astro-ph?searchtype=author&query=Rest%2C+A">Armin Rest</a>, <a href="/search/astro-ph?searchtype=author&query=Groh%2C+J+H">Jose H. Groh</a>, <a href="/search/astro-ph?searchtype=author&query=Allan%2C+A">Andrew Allan</a>, <a href="/search/astro-ph?searchtype=author&query=Fransson%2C+C">Claes Fransson</a>, <a href="/search/astro-ph?searchtype=author&query=Smith%2C+N">Nathan Smith</a>, <a href="/search/astro-ph?searchtype=author&query=Hosseinzadeh%2C+G">Griffin Hosseinzadeh</a>, <a href="/search/astro-ph?searchtype=author&query=Filippenko%2C+A+V">Alexei V. Filippenko</a>, <a href="/search/astro-ph?searchtype=author&query=Andrews%2C+J">Jennifer Andrews</a>, <a href="/search/astro-ph?searchtype=author&query=Bostroem%2C+K+A">K. Azalee Bostroem</a>, <a href="/search/astro-ph?searchtype=author&query=Brink%2C+T+G">Thomas G. Brink</a>, <a href="/search/astro-ph?searchtype=author&query=Brown%2C+P">Peter Brown</a>, <a href="/search/astro-ph?searchtype=author&query=Burke%2C+J">Jamison Burke</a>, <a href="/search/astro-ph?searchtype=author&query=Chevalier%2C+R">Roger Chevalier</a>, <a href="/search/astro-ph?searchtype=author&query=Clayton%2C+G+C">Geoffrey C. Clayton</a>, <a href="/search/astro-ph?searchtype=author&query=Dai%2C+M">Mi Dai</a>, <a href="/search/astro-ph?searchtype=author&query=Davis%2C+K+W">Kyle W. Davis</a>, <a href="/search/astro-ph?searchtype=author&query=Foley%2C+R+J">Ryan J. Foley</a>, <a href="/search/astro-ph?searchtype=author&query=Gomez%2C+S">Sebastian Gomez</a>, <a href="/search/astro-ph?searchtype=author&query=Harris%2C+C">Chelsea Harris</a> , et al. (33 additional authors not shown) </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2305.05015v1-abstract-short" style="display: inline;"> A growing number of supernovae (SNe) are now known to exhibit evidence for significant interaction with a dense, pre-existing, circumstellar medium (CSM). SNe Ibn comprise one such class that can be characterised by both rapidly evolving light curves and persistent narrow He I lines. The origin of such a dense CSM in these systems remains a pressing question, specifically concerning the progenitor… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2305.05015v1-abstract-full').style.display = 'inline'; document.getElementById('2305.05015v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2305.05015v1-abstract-full" style="display: none;"> A growing number of supernovae (SNe) are now known to exhibit evidence for significant interaction with a dense, pre-existing, circumstellar medium (CSM). SNe Ibn comprise one such class that can be characterised by both rapidly evolving light curves and persistent narrow He I lines. The origin of such a dense CSM in these systems remains a pressing question, specifically concerning the progenitor system and mass-loss mechanism. In this paper, we present multi-wavelength data of the Type Ibn SN 2020nxt, including $HST$/STIS ultraviolet spectra. We fit the data with recently updated CMFGEN models designed to handle configurations for SNe Ibn. The UV coverage yields strong constraints on the energetics and, when combined with the CMFGEN models, offer new insight on potential progenitor systems. We find the most successful model is a $\lesssim4 {\rm M}_\odot$ helium star that lost its $\sim 1\,{\rm M}_\odot$ He-rich envelope in the years preceding core collapse. We also consider viable alternatives, such as a He white dwarf merger. Ultimately, we conclude at least some SNe Ibn do not arise from single, massive ($>30 {\rm M}_\odot$) Wolf-Rayet-like stars. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2305.05015v1-abstract-full').style.display = 'none'; document.getElementById('2305.05015v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 8 May, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> May 2023. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">17 pages, 13 figures, 1 table, submitted to MNRAS</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2305.03071">arXiv:2305.03071</a> <span> [<a href="https://arxiv.org/pdf/2305.03071">pdf</a>, <a href="https://arxiv.org/format/2305.03071">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="High Energy Astrophysical Phenomena">astro-ph.HE</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.3847/2041-8213/ace7c0">10.3847/2041-8213/ace7c0 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> The Early Light Curve of SN 2023bee: Constraining Type Ia Supernova Progenitors the Apian Way </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Hosseinzadeh%2C+G">Griffin Hosseinzadeh</a>, <a href="/search/astro-ph?searchtype=author&query=Sand%2C+D+J">David J. Sand</a>, <a href="/search/astro-ph?searchtype=author&query=Sarbadhicary%2C+S+K">Sumit K. Sarbadhicary</a>, <a href="/search/astro-ph?searchtype=author&query=Ryder%2C+S+D">Stuart D. Ryder</a>, <a href="/search/astro-ph?searchtype=author&query=Jha%2C+S+W">Saurabh W. Jha</a>, <a href="/search/astro-ph?searchtype=author&query=Dong%2C+Y">Yize Dong</a>, <a href="/search/astro-ph?searchtype=author&query=Bostroem%2C+K+A">K. Azalee Bostroem</a>, <a href="/search/astro-ph?searchtype=author&query=Andrews%2C+J+E">Jennifer E. Andrews</a>, <a href="/search/astro-ph?searchtype=author&query=Hoang%2C+E">Emily Hoang</a>, <a href="/search/astro-ph?searchtype=author&query=Janzen%2C+D">Daryl Janzen</a>, <a href="/search/astro-ph?searchtype=author&query=Jencson%2C+J+E">Jacob E. Jencson</a>, <a href="/search/astro-ph?searchtype=author&query=Lundquist%2C+M">Michael Lundquist</a>, <a href="/search/astro-ph?searchtype=author&query=Retamal%2C+N+E+M">Nicolas E. Meza Retamal</a>, <a href="/search/astro-ph?searchtype=author&query=Pearson%2C+J">Jeniveve Pearson</a>, <a href="/search/astro-ph?searchtype=author&query=Shrestha%2C+M">Manisha Shrestha</a>, <a href="/search/astro-ph?searchtype=author&query=Valenti%2C+S">Stefano Valenti</a>, <a href="/search/astro-ph?searchtype=author&query=Wyatt%2C+S">Samuel Wyatt</a>, <a href="/search/astro-ph?searchtype=author&query=Farah%2C+J">Joseph Farah</a>, <a href="/search/astro-ph?searchtype=author&query=Howell%2C+D+A">D. Andrew Howell</a>, <a href="/search/astro-ph?searchtype=author&query=McCully%2C+C">Curtis McCully</a>, <a href="/search/astro-ph?searchtype=author&query=Newsome%2C+M">Megan Newsome</a>, <a href="/search/astro-ph?searchtype=author&query=Gonzalez%2C+E+P">Estefania Padilla Gonzalez</a>, <a href="/search/astro-ph?searchtype=author&query=Pellegrino%2C+C">Craig Pellegrino</a>, <a href="/search/astro-ph?searchtype=author&query=Terreran%2C+G">Giacomo Terreran</a>, <a href="/search/astro-ph?searchtype=author&query=Alzaabi%2C+M">Muzoun Alzaabi</a> , et al. (17 additional authors not shown) </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2305.03071v2-abstract-short" style="display: inline;"> We present very early photometric and spectroscopic observations of the Type Ia supernova (SN Ia) 2023bee, starting about 8 hr after the explosion, which reveal a strong excess in the optical and nearest UV (U and UVW1) bands during the first several days of explosion. This data set allows us to probe the nature of the binary companion of the exploding white dwarf and the conditions leading to its… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2305.03071v2-abstract-full').style.display = 'inline'; document.getElementById('2305.03071v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2305.03071v2-abstract-full" style="display: none;"> We present very early photometric and spectroscopic observations of the Type Ia supernova (SN Ia) 2023bee, starting about 8 hr after the explosion, which reveal a strong excess in the optical and nearest UV (U and UVW1) bands during the first several days of explosion. This data set allows us to probe the nature of the binary companion of the exploding white dwarf and the conditions leading to its ignition. We find a good match to the Kasen model in which a main-sequence companion star stings the ejecta with a shock as they buzz past. Models of double detonations, shells of radioactive nickel near the surface, interaction with circumstellar material, and pulsational delayed detonations do not provide good matches to our light curves. We also observe signatures of unburned material, in the form of carbon absorption, in our earliest spectra. Our radio nondetections place a limit on the mass-loss rate from the putative companion that rules out a red giant but allows a main-sequence star. We discuss our results in the context of other similar SNe Ia in the literature. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2305.03071v2-abstract-full').style.display = 'none'; document.getElementById('2305.03071v2-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 8 August, 2023; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 4 May, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> May 2023. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">updated to match accepted version</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> The Astrophysical Journal Letters, 953:L15 (12pp), 2023 August 10 </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2305.01694">arXiv:2305.01694</a> <span> [<a href="https://arxiv.org/pdf/2305.01694">pdf</a>, <a href="https://arxiv.org/format/2305.01694">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Astrophysics of Galaxies">astro-ph.GA</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="High Energy Astrophysical Phenomena">astro-ph.HE</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.3847/1538-4357/ace1ee">10.3847/1538-4357/ace1ee <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> AT 2021loi: A Bowen Fluorescence Flare with a Rebrightening Episode, Occurring in a Previously-Known AGN </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Makrygianni%2C+L">Lydia Makrygianni</a>, <a href="/search/astro-ph?searchtype=author&query=Trakhtenbrot%2C+B">Benny Trakhtenbrot</a>, <a href="/search/astro-ph?searchtype=author&query=Arcavi%2C+I">Iair Arcavi</a>, <a href="/search/astro-ph?searchtype=author&query=Ricci%2C+C">Claudio Ricci</a>, <a href="/search/astro-ph?searchtype=author&query=Lam%2C+M+C">Marco C. Lam</a>, <a href="/search/astro-ph?searchtype=author&query=Horesh%2C+A">Assaf Horesh</a>, <a href="/search/astro-ph?searchtype=author&query=Sfaradi%2C+I">Itai Sfaradi</a>, <a href="/search/astro-ph?searchtype=author&query=Bostroem%2C+K+A">K. Azalee Bostroem</a>, <a href="/search/astro-ph?searchtype=author&query=Hosseinzadeh%2C+G">Griffin Hosseinzadeh</a>, <a href="/search/astro-ph?searchtype=author&query=Howell%2C+D+A">D. Andrew Howell</a>, <a href="/search/astro-ph?searchtype=author&query=Pellegrino%2C+C">Craig Pellegrino</a>, <a href="/search/astro-ph?searchtype=author&query=Fender%2C+R">Rob Fender</a>, <a href="/search/astro-ph?searchtype=author&query=Green%2C+D+A">David A. Green</a>, <a href="/search/astro-ph?searchtype=author&query=Williams%2C+D+R+A">David R. A. Williams</a>, <a href="/search/astro-ph?searchtype=author&query=Bright%2C+J">Joe Bright</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2305.01694v1-abstract-short" style="display: inline;"> AT 2021loi is an optical-ultraviolet transient located at the center of its host galaxy. Its spectral features identify it as a member of the ``Bowen Fluorescence Flare'' (BFF) class. The first member of this class was considered to be related to a tidal disruption event, but enhanced accretion onto an already active supermassive black hole was suggested as an alternative explanation. AT 2021loi,… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2305.01694v1-abstract-full').style.display = 'inline'; document.getElementById('2305.01694v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2305.01694v1-abstract-full" style="display: none;"> AT 2021loi is an optical-ultraviolet transient located at the center of its host galaxy. Its spectral features identify it as a member of the ``Bowen Fluorescence Flare'' (BFF) class. The first member of this class was considered to be related to a tidal disruption event, but enhanced accretion onto an already active supermassive black hole was suggested as an alternative explanation. AT 2021loi, having occurred in a previously-known unobscured AGN, strengthens the latter interpretation. Its light curve is similar to those of previous BFFs, showing a rebrightening approximately one year after the main peak (which was not explicitly identified, but might be the case, in all previous BFFs). An emission feature around 4680 A, seen in the pre-flare spectrum, strengthens by a factor of $\sim$2 around the optical peak of the flare, and is clearly seen as a double peaked feature then, suggesting a blend of NIII $位4640$ with HeII $\lambda4686$ as its origin. The appearance of OIII $位$3133 and possible NIII $位\lambda4097,4103$ (blended with H$未$) during the flare further support a Bowen Fluorescence classification. Here, we present ZTF, ATLAS, Keck, Las Cumbres Observatory, NEOWISE-R, $Swift$, AMI and VLA observations of AT 2021loi, making it one of the best observed BFFs to date. AT 2021loi thus provides some clarity on the nature of BFFs but also further demonstrates the diversity of nuclear transients. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2305.01694v1-abstract-full').style.display = 'none'; document.getElementById('2305.01694v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 2 May, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> May 2023. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">Submitted to ApJ. This version addresses comments from the referee</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2305.01654">arXiv:2305.01654</a> <span> [<a href="https://arxiv.org/pdf/2305.01654">pdf</a>, <a href="https://arxiv.org/format/2305.01654">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="High Energy Astrophysical Phenomena">astro-ph.HE</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.3847/2041-8213/ace31c">10.3847/2041-8213/ace31c <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> SN 2022acko: the First Early Far-Ultraviolet Spectra of a Type IIP Supernova </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Bostroem%2C+K+A">K. Azalee Bostroem</a>, <a href="/search/astro-ph?searchtype=author&query=Dessart%2C+L">Luc Dessart</a>, <a href="/search/astro-ph?searchtype=author&query=Hillier%2C+D+J">D. John Hillier</a>, <a href="/search/astro-ph?searchtype=author&query=Lundquist%2C+M">Michael Lundquist</a>, <a href="/search/astro-ph?searchtype=author&query=Andrews%2C+J+E">Jennifer E. Andrews</a>, <a href="/search/astro-ph?searchtype=author&query=Sand%2C+D+J">David J. Sand</a>, <a href="/search/astro-ph?searchtype=author&query=Dong%2C+Y">Yize Dong</a>, <a href="/search/astro-ph?searchtype=author&query=Valenti%2C+S">Stefano Valenti</a>, <a href="/search/astro-ph?searchtype=author&query=Haislip%2C+J">Joshua Haislip</a>, <a href="/search/astro-ph?searchtype=author&query=Hoang%2C+E+T">Emily T. Hoang</a>, <a href="/search/astro-ph?searchtype=author&query=Hosseinzadeh%2C+G">Griffin Hosseinzadeh</a>, <a href="/search/astro-ph?searchtype=author&query=Janzen%2C+D">Daryl Janzen</a>, <a href="/search/astro-ph?searchtype=author&query=Jencson%2C+J+E">Jacob E. Jencson</a>, <a href="/search/astro-ph?searchtype=author&query=Jha%2C+S+W">Saurabh W. Jha</a>, <a href="/search/astro-ph?searchtype=author&query=Kouprianov%2C+V">Vladimir Kouprianov</a>, <a href="/search/astro-ph?searchtype=author&query=Pearson%2C+J">Jeniveve Pearson</a>, <a href="/search/astro-ph?searchtype=author&query=Retamal%2C+N+E+M">Nicolas E. Meza Retamal</a>, <a href="/search/astro-ph?searchtype=author&query=Reichart%2C+D+E">Daniel E. Reichart</a>, <a href="/search/astro-ph?searchtype=author&query=Shrestha%2C+M">Manisha Shrestha</a>, <a href="/search/astro-ph?searchtype=author&query=Ashall%2C+C">Christopher Ashall</a>, <a href="/search/astro-ph?searchtype=author&query=Baron%2C+E">E. Baron</a>, <a href="/search/astro-ph?searchtype=author&query=Brown%2C+P+J">Peter J. Brown</a>, <a href="/search/astro-ph?searchtype=author&query=DerKacy%2C+J+M">James M. DerKacy</a>, <a href="/search/astro-ph?searchtype=author&query=Farah%2C+J">Joseph Farah</a>, <a href="/search/astro-ph?searchtype=author&query=Galbany%2C+L">Lluis Galbany</a> , et al. (19 additional authors not shown) </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2305.01654v2-abstract-short" style="display: inline;"> We present five far- and near-ultraviolet spectra of the Type II plateau supernova, SN 2022acko, obtained 5, 6, 7, 19, and 21 days after explosion, all observed with the Hubble Space Telescope/Space Telescope Imaging Spectrograph. The first three epochs are earlier than any Type II plateau supernova has been observed in the far-ultraviolet revealing unprecedented characteristics. These three spect… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2305.01654v2-abstract-full').style.display = 'inline'; document.getElementById('2305.01654v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2305.01654v2-abstract-full" style="display: none;"> We present five far- and near-ultraviolet spectra of the Type II plateau supernova, SN 2022acko, obtained 5, 6, 7, 19, and 21 days after explosion, all observed with the Hubble Space Telescope/Space Telescope Imaging Spectrograph. The first three epochs are earlier than any Type II plateau supernova has been observed in the far-ultraviolet revealing unprecedented characteristics. These three spectra are dominated by strong lines, primarily from metals, which contrasts with the relatively featureless early optical spectra. The flux decreases over the initial time series as the ejecta cools and line-blanketing takes effect. We model this unique dataset with the non-local thermodynamic equilibrium radiation transport code CMFGEN, finding a good match to the explosion of a low mass red supergiant with energy Ekin = 6 x 10^50 erg. With these models we identify, for the first time, the ions that dominate the early UV spectra. We also present optical photometry and spectroscopy, showing that SN 2022acko has a peak absolute magnitude of V = -15.4 mag and plateau length of ~115d. The spectra closely resemble those of SN 2005cs and SN 2012A. Using the combined optical and UV spectra, we report the fraction of flux redwards of the uvw2, U, B, and V filters on days 5, 7, and 19. We also create a spectral time-series of Type II supernovae in the ultraviolet, demonstrating the rapid decline of UV flux over the first few weeks of evolution. Future observations of Type II supernovae will continue to explore the diversity seen in the limited set of high-quality UV spectra. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2305.01654v2-abstract-full').style.display = 'none'; document.getElementById('2305.01654v2-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 12 December, 2023; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 1 May, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> May 2023. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">Published in ApJL</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> The Astrophysical Journal Letters, Volume 953, Issue 2, id.L18, 18 pp., August 2023 </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2304.06764">arXiv:2304.06764</a> <span> [<a href="https://arxiv.org/pdf/2304.06764">pdf</a>, <a href="https://arxiv.org/format/2304.06764">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Astrophysics of Galaxies">astro-ph.GA</span> </div> </div> <p class="title is-5 mathjax"> What Does the Virial Coefficient of the \Hb Broad-Line Region Depend On? </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Villafa%C3%B1a%2C+L">Lizvette Villafa帽a</a>, <a href="/search/astro-ph?searchtype=author&query=Williams%2C+P+R">Peter R. Williams</a>, <a href="/search/astro-ph?searchtype=author&query=Treu%2C+T">Tommaso Treu</a>, <a href="/search/astro-ph?searchtype=author&query=Brewer%2C+B+J">Brendon J. Brewer</a>, <a href="/search/astro-ph?searchtype=author&query=Barth%2C+A+J">Aaron J. Barth</a>, <a href="/search/astro-ph?searchtype=author&query=U%2C+V">Vivian U</a>, <a href="/search/astro-ph?searchtype=author&query=Bennert%2C+V+N">Vardha N. Bennert</a>, <a href="/search/astro-ph?searchtype=author&query=Guo%2C+H">Hengxiao Guo</a>, <a href="/search/astro-ph?searchtype=author&query=Bentz%2C+M+C">Misty C. Bentz</a>, <a href="/search/astro-ph?searchtype=author&query=Canalizo%2C+G">Gabriela Canalizo</a>, <a href="/search/astro-ph?searchtype=author&query=Filippenko%2C+A+V">Alexei V. Filippenko</a>, <a href="/search/astro-ph?searchtype=author&query=Gates%2C+E">Elinor Gates</a>, <a href="/search/astro-ph?searchtype=author&query=Joner%2C+M+D">Michael D. Joner</a>, <a href="/search/astro-ph?searchtype=author&query=Malkan%2C+M+A">Matthew A. Malkan</a>, <a href="/search/astro-ph?searchtype=author&query=Woo%2C+J">Jong-Hak Woo</a>, <a href="/search/astro-ph?searchtype=author&query=Abolfathi%2C+B">Bela Abolfathi</a>, <a href="/search/astro-ph?searchtype=author&query=Bohn%2C+T">Thomas Bohn</a>, <a href="/search/astro-ph?searchtype=author&query=Bostroem%2C+K+A">K. Azalee Bostroem</a>, <a href="/search/astro-ph?searchtype=author&query=Brandel%2C+A">Andrew Brandel</a>, <a href="/search/astro-ph?searchtype=author&query=Brink%2C+T+G">Thomas G. Brink</a>, <a href="/search/astro-ph?searchtype=author&query=Channa%2C+S">Sanyum Channa</a>, <a href="/search/astro-ph?searchtype=author&query=Cosens%2C+M">Maren Cosens</a>, <a href="/search/astro-ph?searchtype=author&query=Donohue%2C+E">Edward Donohue</a>, <a href="/search/astro-ph?searchtype=author&query=Halevi%2C+G">Goni Halevi</a>, <a href="/search/astro-ph?searchtype=author&query=Hood%2C+C+E">Carol E. Hood</a> , et al. (15 additional authors not shown) </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2304.06764v1-abstract-short" style="display: inline;"> We combine our dynamical modeling black hole mass measurements from the Lick AGN Monitoring Project 2016 sample with measured cross-correlation time lags and line widths to recover individual scale factors, f, used in traditional reverberation mapping analyses. We extend our sample by including prior results from Code for AGN Reverberation and Modeling of Emission Lines (caramel) studies that have… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2304.06764v1-abstract-full').style.display = 'inline'; document.getElementById('2304.06764v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2304.06764v1-abstract-full" style="display: none;"> We combine our dynamical modeling black hole mass measurements from the Lick AGN Monitoring Project 2016 sample with measured cross-correlation time lags and line widths to recover individual scale factors, f, used in traditional reverberation mapping analyses. We extend our sample by including prior results from Code for AGN Reverberation and Modeling of Emission Lines (caramel) studies that have utilized our methods. Aiming to improve the precision of black hole mass estimates, as well as uncover any regularities in the behavior of the broad-line region (BLR), we search for correlations between f and other AGN/BLR parameters. We find (i) evidence for a correlation between the virial coefficient log10(fmean,蟽) and black hole mass, (ii) marginal evidence for a similar correlation between log10(frms,蟽) and black hole mass, (iii) marginal evidence for an anti-correlation of BLR disk thickness with log10(fmean,FWHM)and log10(frms,FWHM), and (iv) marginal evidence for an anti-correlation of inclination angle with log10(fmean,FWHM), log10(frms,蟽), and log10(fmean,蟽). Lastly, we find marginal evidence for a correlation between line-profile shape, when using the root-meansquare spectrum, log10(FWHM/蟽)rms, and the virial coefficient, log10(frms,蟽), and investigate how BLR properties might be related to line-profile shape using caramel models. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2304.06764v1-abstract-full').style.display = 'none'; document.getElementById('2304.06764v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 13 April, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> April 2023. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">17 pages, 10 figures</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2302.03829">arXiv:2302.03829</a> <span> [<a href="https://arxiv.org/pdf/2302.03829">pdf</a>, <a href="https://arxiv.org/format/2302.03829">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="High Energy Astrophysical Phenomena">astro-ph.HE</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.3847/2041-8213/acbd50">10.3847/2041-8213/acbd50 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Limit on Supernova Emission in the Brightest Gamma-ray Burst, GRB 221009A </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Shrestha%2C+M">Manisha Shrestha</a>, <a href="/search/astro-ph?searchtype=author&query=Sand%2C+D+J">David J. Sand</a>, <a href="/search/astro-ph?searchtype=author&query=Alexander%2C+K+D">Kate D. Alexander</a>, <a href="/search/astro-ph?searchtype=author&query=Bostroem%2C+K+A">K. Azalee Bostroem</a>, <a href="/search/astro-ph?searchtype=author&query=Hosseinzadeh%2C+G">Griffin Hosseinzadeh</a>, <a href="/search/astro-ph?searchtype=author&query=Pearson%2C+J">Jeniveve Pearson</a>, <a href="/search/astro-ph?searchtype=author&query=Aghakhanloo%2C+M">Mojgan Aghakhanloo</a>, <a href="/search/astro-ph?searchtype=author&query=Vink%C3%B3%2C+J">J贸zsef Vink贸</a>, <a href="/search/astro-ph?searchtype=author&query=Andrews%2C+J+E">Jennifer E. Andrews</a>, <a href="/search/astro-ph?searchtype=author&query=Jencson%2C+J+E">Jacob E. Jencson</a>, <a href="/search/astro-ph?searchtype=author&query=Lundquist%2C+M+J">M. J. Lundquist</a>, <a href="/search/astro-ph?searchtype=author&query=Wyatt%2C+S">Samuel Wyatt</a>, <a href="/search/astro-ph?searchtype=author&query=Howell%2C+D+A">D. Andrew Howell</a>, <a href="/search/astro-ph?searchtype=author&query=McCully%2C+C">Curtis McCully</a>, <a href="/search/astro-ph?searchtype=author&query=Gonzalez%2C+E+P">Estefania Padilla Gonzalez</a>, <a href="/search/astro-ph?searchtype=author&query=Pellegrino%2C+C">Craig Pellegrino</a>, <a href="/search/astro-ph?searchtype=author&query=Terreran%2C+G">Giacomo Terreran</a>, <a href="/search/astro-ph?searchtype=author&query=Hiramatsu%2C+D">Daichi Hiramatsu</a>, <a href="/search/astro-ph?searchtype=author&query=Newsome%2C+M">Megan Newsome</a>, <a href="/search/astro-ph?searchtype=author&query=Farah%2C+J">Joseph Farah</a>, <a href="/search/astro-ph?searchtype=author&query=Jha%2C+S+W">Saurabh W. Jha</a>, <a href="/search/astro-ph?searchtype=author&query=Smith%2C+N">Nathan Smith</a>, <a href="/search/astro-ph?searchtype=author&query=Wheeler%2C+J+C">J. Craig Wheeler</a>, <a href="/search/astro-ph?searchtype=author&query=Mart%C3%ADnez-V%C3%A1zquez%2C+C">Clara Mart铆nez-V谩zquez</a>, <a href="/search/astro-ph?searchtype=author&query=Carballo-Bello%2C+J+A">Julio A. Carballo-Bello</a> , et al. (8 additional authors not shown) </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2302.03829v2-abstract-short" style="display: inline;"> We present photometric and spectroscopic observations of the extraordinary gamma-ray burst (GRB) 221009A in search of an associated supernova. Some past GRBs have shown bumps in the optical light curve that coincide with the emergence of supernova spectral features, but we do not detect any significant light curve features in GRB~221009A, nor do we detect any clear sign of supernova spectral featu… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2302.03829v2-abstract-full').style.display = 'inline'; document.getElementById('2302.03829v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2302.03829v2-abstract-full" style="display: none;"> We present photometric and spectroscopic observations of the extraordinary gamma-ray burst (GRB) 221009A in search of an associated supernova. Some past GRBs have shown bumps in the optical light curve that coincide with the emergence of supernova spectral features, but we do not detect any significant light curve features in GRB~221009A, nor do we detect any clear sign of supernova spectral features. Using two well-studied GRB-associated supernovae (SN~2013dx, $M_{r,max} = -19.54$; SN~2016jca, $M_{r,max} = -19.04$) at a similar redshift as GRB~221009A ($z=0.151$), we modeled how the emergence of a supernova would affect the light curve. If we assume the GRB afterglow to decay at the same rate as the X-ray data, the combination of afterglow and a supernova component is fainter than the observed GRB brightness. For the case where we assume the best-fit power law to the optical data as the GRB afterglow component, a supernova contribution should have created a clear bump in the light curve, assuming only extinction from the Milky Way. If we assume a higher extinction of $E(B-V)$=$1.74$ mag (as has been suggested elsewhere), the supernova contribution would have been hard to detect, with a limit on the associated supernova of $M_{r,max} \approx-$19.54. We do not observe any clear supernova features in our spectra, which were taken around the time of expected maximum light. The lack of a bright supernova associated with GRB~221009A may indicate that the energy from the explosion is mostly concentrated in the jet, leaving a lower energy budget available for the supernova. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2302.03829v2-abstract-full').style.display = 'none'; document.getElementById('2302.03829v2-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 7 March, 2023; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 7 February, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> February 2023. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">19 pages, 8 figures, 4 tables, accepted for publication in ApJL</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2302.00274">arXiv:2302.00274</a> <span> [<a href="https://arxiv.org/pdf/2302.00274">pdf</a>, <a href="https://arxiv.org/format/2302.00274">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="High Energy Astrophysical Phenomena">astro-ph.HE</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Astrophysics of Galaxies">astro-ph.GA</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1093/mnras/stad2001">10.1093/mnras/stad2001 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Identifying the SN 2022acko progenitor with JWST </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Van+Dyk%2C+S+D">Schuyler D. Van Dyk</a>, <a href="/search/astro-ph?searchtype=author&query=Bostroem%2C+K+A">K. Azalee Bostroem</a>, <a href="/search/astro-ph?searchtype=author&query=Zheng%2C+W">WeiKang Zheng</a>, <a href="/search/astro-ph?searchtype=author&query=Brink%2C+T+G">Thomas G. Brink</a>, <a href="/search/astro-ph?searchtype=author&query=Fox%2C+O+D">Ori D. Fox</a>, <a href="/search/astro-ph?searchtype=author&query=Andrews%2C+J+E">Jennifer E. Andrews</a>, <a href="/search/astro-ph?searchtype=author&query=Filippenko%2C+A+V">Alexei V. Filippenko</a>, <a href="/search/astro-ph?searchtype=author&query=Dong%2C+Y">Yize Dong</a>, <a href="/search/astro-ph?searchtype=author&query=Hoang%2C+E">Emily Hoang</a>, <a href="/search/astro-ph?searchtype=author&query=Hosseinzadeh%2C+G">Griffin Hosseinzadeh</a>, <a href="/search/astro-ph?searchtype=author&query=Janzen%2C+D">Daryl Janzen</a>, <a href="/search/astro-ph?searchtype=author&query=Jencson%2C+J+E">Jacob E. Jencson</a>, <a href="/search/astro-ph?searchtype=author&query=Lundquist%2C+M+J">Michael J. Lundquist</a>, <a href="/search/astro-ph?searchtype=author&query=Meza%2C+N">Nicolas Meza</a>, <a href="/search/astro-ph?searchtype=author&query=Milisavljevic%2C+D">Dan Milisavljevic</a>, <a href="/search/astro-ph?searchtype=author&query=Pearson%2C+J">Jeniveve Pearson</a>, <a href="/search/astro-ph?searchtype=author&query=Sand%2C+D+J">David J. Sand</a>, <a href="/search/astro-ph?searchtype=author&query=Shrestha%2C+M">Manisha Shrestha</a>, <a href="/search/astro-ph?searchtype=author&query=Valenti%2C+S">Stefano Valenti</a>, <a href="/search/astro-ph?searchtype=author&query=Howell%2C+D+A">D. Andrew Howell</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2302.00274v2-abstract-short" style="display: inline;"> We report on analysis using the James Webb Space Telescope (JWST) to identify a candidate progenitor star of the Type II-plateau supernova SN 2022acko in the nearby, barred spiral galaxy NGC 1300. To our knowledge, our discovery represents the first time JWST has been used to localize a progenitor system in pre-explosion archival Hubble Space Telescope (HST) images. We astrometrically registered a… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2302.00274v2-abstract-full').style.display = 'inline'; document.getElementById('2302.00274v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2302.00274v2-abstract-full" style="display: none;"> We report on analysis using the James Webb Space Telescope (JWST) to identify a candidate progenitor star of the Type II-plateau supernova SN 2022acko in the nearby, barred spiral galaxy NGC 1300. To our knowledge, our discovery represents the first time JWST has been used to localize a progenitor system in pre-explosion archival Hubble Space Telescope (HST) images. We astrometrically registered a JWST NIRCam image from 2023 January, in which the SN was serendipitously captured, to pre-SN HST F160W and F814W images from 2017 and 2004, respectively. An object corresponding precisely to the SN position has been isolated with reasonable confidence. That object has a spectral energy distribution (SED) and overall luminosity consistent with a single-star model having an initial mass possibly somewhat less than the canonical 8 Msun theoretical threshold for core collapse (although masses as high as 9 Msun for the star are also possible); however, the star's SED and luminosity are inconsistent with that of a super-asymptotic giant branch star which might be a forerunner of an electron-capture SN. The properties of the progenitor alone imply that SN 2022acko is a relatively normal SN II-P, albeit most likely a low-luminosity one. The progenitor candidate should be confirmed with follow-up HST imaging at late times, when the SN has sufficiently faded. This potential use of JWST opens a new era of identifying SN progenitor candidates at high spatial resolution. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2302.00274v2-abstract-full').style.display = 'none'; document.getElementById('2302.00274v2-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 3 July, 2023; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 1 February, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> February 2023. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">8 pages, substantial changes from v1, to appear in MNRAS</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2301.04662">arXiv:2301.04662</a> <span> [<a href="https://arxiv.org/pdf/2301.04662">pdf</a>, <a href="https://arxiv.org/format/2301.04662">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="High Energy Astrophysical Phenomena">astro-ph.HE</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.3847/1538-4357/ace595">10.3847/1538-4357/ace595 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> SN 2020bio: A Double-peaked, H-poor Type IIb Supernova with Evidence of Circumstellar Interaction </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Pellegrino%2C+C">C. Pellegrino</a>, <a href="/search/astro-ph?searchtype=author&query=Hiramatsu%2C+D">D. Hiramatsu</a>, <a href="/search/astro-ph?searchtype=author&query=Arcavi%2C+I">I. Arcavi</a>, <a href="/search/astro-ph?searchtype=author&query=Howell%2C+D+A">D. A. Howell</a>, <a href="/search/astro-ph?searchtype=author&query=Bostroem%2C+K+A">K. A. Bostroem</a>, <a href="/search/astro-ph?searchtype=author&query=Brown%2C+P+J">P. J. Brown</a>, <a href="/search/astro-ph?searchtype=author&query=Burke%2C+J">J. Burke</a>, <a href="/search/astro-ph?searchtype=author&query=Elias-Rosa%2C+N">N. Elias-Rosa</a>, <a href="/search/astro-ph?searchtype=author&query=Itagaki%2C+K">K. Itagaki</a>, <a href="/search/astro-ph?searchtype=author&query=Kaneda%2C+H">H. Kaneda</a>, <a href="/search/astro-ph?searchtype=author&query=McCully%2C+C">C. McCully</a>, <a href="/search/astro-ph?searchtype=author&query=Modjaz%2C+M">M. Modjaz</a>, <a href="/search/astro-ph?searchtype=author&query=Gonzalez%2C+E+P">E. Padilla Gonzalez</a>, <a href="/search/astro-ph?searchtype=author&query=Pritchard%2C+T+A">T. A. Pritchard</a>, <a href="/search/astro-ph?searchtype=author&query=Yesmin%2C+N">N. Yesmin</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2301.04662v2-abstract-short" style="display: inline;"> We present photometric and spectroscopic observations of SN 2020bio, a double-peaked Type IIb supernova (SN) discovered within a day of explosion, primarily obtained by Las Cumbres Observatory and Swift. SN 2020bio displays a rapid and long-lasting initial decline throughout the first week of its light curve, similarly to other well-studied Type IIb SNe. This early-time emission is thought to orig… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2301.04662v2-abstract-full').style.display = 'inline'; document.getElementById('2301.04662v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2301.04662v2-abstract-full" style="display: none;"> We present photometric and spectroscopic observations of SN 2020bio, a double-peaked Type IIb supernova (SN) discovered within a day of explosion, primarily obtained by Las Cumbres Observatory and Swift. SN 2020bio displays a rapid and long-lasting initial decline throughout the first week of its light curve, similarly to other well-studied Type IIb SNe. This early-time emission is thought to originate from the cooling of the extended outer hydrogen-rich (H-rich) envelope of the progenitor star that is shock heated by the SN explosion. We compare SN 2020bio to a sample of other double-peaked Type IIb SNe in order to investigate its progenitor properties. Analytical model fits to the early-time emission give progenitor radius ($\approx$ 100--1500 $R_\odot$) and H-rich envelope mass ($\approx$ 0.01--0.5 $M_\odot$) estimates that are consistent with other Type IIb SNe. However, SN 2020bio displays several peculiarities, including: (1) weak H spectral features indicating a greater amount of mass loss than other Type IIb progenitors; (2) an underluminous secondary light-curve peak that implies a small amount of synthesized $^{56}$Ni ($M_{\text{Ni}}$ $\approx$ 0.02 $M_\odot$); and (3) low-luminosity nebular [O I] and interaction-powered nebular features. These observations are more consistent with a lower-mass progenitor ($M_{\text{ZAMS}} \approx$ 12 $M_\odot$) that was stripped of most of its H-rich envelope before exploding. This study adds to the growing diversity in the observed properties of Type IIb SNe and their progenitors. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2301.04662v2-abstract-full').style.display = 'none'; document.getElementById('2301.04662v2-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 22 August, 2023; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 11 January, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> January 2023. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">23 pages, 15 figures, published in ApJ</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> The Astrophysical Journal, Volume 954, page 35, 2023 </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2301.03647">arXiv:2301.03647</a> <span> [<a href="https://arxiv.org/pdf/2301.03647">pdf</a>, <a href="https://arxiv.org/format/2301.03647">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="High Energy Astrophysical Phenomena">astro-ph.HE</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.3847/2041-8213/acb8a8">10.3847/2041-8213/acb8a8 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> JWST Low-Resolution MIRI Spectral Observations of SN~2021aefx: High-density Burning in a Type Ia Supernova </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=DerKacy%2C+J+M">J. M. DerKacy</a>, <a href="/search/astro-ph?searchtype=author&query=Ashall%2C+C">C. Ashall</a>, <a href="/search/astro-ph?searchtype=author&query=Hoeflich%2C+P">P. Hoeflich</a>, <a href="/search/astro-ph?searchtype=author&query=Baron%2C+E">E. Baron</a>, <a href="/search/astro-ph?searchtype=author&query=Shappee%2C+B+J">B. J. Shappee</a>, <a href="/search/astro-ph?searchtype=author&query=Baade%2C+D">D. Baade</a>, <a href="/search/astro-ph?searchtype=author&query=Andrews%2C+J">J. Andrews</a>, <a href="/search/astro-ph?searchtype=author&query=Bostroem%2C+K+A">K. A. Bostroem</a>, <a href="/search/astro-ph?searchtype=author&query=Brown%2C+P+J">P. J. Brown</a>, <a href="/search/astro-ph?searchtype=author&query=Burns%2C+C+R">C. R. Burns</a>, <a href="/search/astro-ph?searchtype=author&query=Burrow%2C+A">A. Burrow</a>, <a href="/search/astro-ph?searchtype=author&query=Cikota%2C+A">A. Cikota</a>, <a href="/search/astro-ph?searchtype=author&query=de+Jaeger%2C+T">T. de Jaeger</a>, <a href="/search/astro-ph?searchtype=author&query=Do%2C+A">A. Do</a>, <a href="/search/astro-ph?searchtype=author&query=Dong%2C+Y">Y. Dong</a>, <a href="/search/astro-ph?searchtype=author&query=Dominguez%2C+I">I. Dominguez</a>, <a href="/search/astro-ph?searchtype=author&query=Galbany%2C+L">L. Galbany</a>, <a href="/search/astro-ph?searchtype=author&query=Hsiao%2C+E+Y">E. Y. Hsiao</a>, <a href="/search/astro-ph?searchtype=author&query=Karamehmetoglu%2C+E">E. Karamehmetoglu</a>, <a href="/search/astro-ph?searchtype=author&query=Krisciunas%2C+K">K. Krisciunas</a>, <a href="/search/astro-ph?searchtype=author&query=Kumar%2C+S">S. Kumar</a>, <a href="/search/astro-ph?searchtype=author&query=Lu%2C+J">J. Lu</a>, <a href="/search/astro-ph?searchtype=author&query=Evans%2C+T+B+M">T. B. Mera Evans</a>, <a href="/search/astro-ph?searchtype=author&query=Maund%2C+J+R">J. R. Maund</a>, <a href="/search/astro-ph?searchtype=author&query=Mazzali%2C+P">P. Mazzali</a> , et al. (16 additional authors not shown) </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2301.03647v2-abstract-short" style="display: inline;"> We present a JWST/MIRI low-resolution mid-infrared (MIR) spectroscopic observation of the normal Type Ia supernova (SN Ia) SN 2021aefx at +323 days past rest-frame B-band maximum light. The spectrum ranges from 4-14 um, and shows many unique qualities including a flat-topped [Ar III] 8.991 um profile, a strongly tilted [Co III] 11.888 um feature, and multiple stable Ni lines. These features provid… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2301.03647v2-abstract-full').style.display = 'inline'; document.getElementById('2301.03647v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2301.03647v2-abstract-full" style="display: none;"> We present a JWST/MIRI low-resolution mid-infrared (MIR) spectroscopic observation of the normal Type Ia supernova (SN Ia) SN 2021aefx at +323 days past rest-frame B-band maximum light. The spectrum ranges from 4-14 um, and shows many unique qualities including a flat-topped [Ar III] 8.991 um profile, a strongly tilted [Co III] 11.888 um feature, and multiple stable Ni lines. These features provide critical information about the physics of the explosion. The observations are compared to synthetic spectra from detailed NLTE multi-dimensional models. The results of the best-fitting model are used to identify the components of the spectral blends and provide a quantitative comparison to the explosion physics. Emission line profiles and the presence of electron capture (EC) elements are used to constrain the mass of the exploding white dwarf (WD) and the chemical asymmetries in the ejecta. We show that the observations of SN 2021aefx are consistent with an off-center delayed-detonation explosion of a near-Chandrasekhar mass (Mch) WD at a viewing angle of -30 degrees relative to the point of the deflagration-to-detonation transition. From the strength of the stable Ni lines we determine that there is little to no mixing in the central regions of the ejecta. Based on both the presence of stable Ni and the Ar velocity distributions, we obtain a strict lower limit of 1.2 Msun of the initial WD, implying that most sub-Mch explosions models are not viable models for SN 2021aefx. The analysis here shows the crucial importance of MIR spectra for distinguishing between explosion scenarios for SNe Ia. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2301.03647v2-abstract-full').style.display = 'none'; document.getElementById('2301.03647v2-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 2 February, 2023; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 9 January, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> January 2023. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">21 pages, 9 figures, 4 tables, accepted to ApJL; updated to accepted version</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2211.04808">arXiv:2211.04808</a> <span> [<a href="https://arxiv.org/pdf/2211.04808">pdf</a>, <a href="https://arxiv.org/format/2211.04808">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="High Energy Astrophysical Phenomena">astro-ph.HE</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.3847/1538-4357/aca1b7">10.3847/1538-4357/aca1b7 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> A Multi-Wavelength View on the Rapidly-Evolving Supernova 2018ivc: An Analog of SN IIb 1993J but Powered Primarily by Circumstellar Interaction </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Maeda%2C+K">Keiichi Maeda</a>, <a href="/search/astro-ph?searchtype=author&query=Chandra%2C+P">Poonam Chandra</a>, <a href="/search/astro-ph?searchtype=author&query=Moriya%2C+T+J">Takashi J. Moriya</a>, <a href="/search/astro-ph?searchtype=author&query=Reguitti%2C+A">Andrea Reguitti</a>, <a href="/search/astro-ph?searchtype=author&query=Ryder%2C+S">Stuart Ryder</a>, <a href="/search/astro-ph?searchtype=author&query=Matsuoka%2C+T">Tomoki Matsuoka</a>, <a href="/search/astro-ph?searchtype=author&query=Michiyama%2C+T">Tomonari Michiyama</a>, <a href="/search/astro-ph?searchtype=author&query=Pignata%2C+G">Giuliano Pignata</a>, <a href="/search/astro-ph?searchtype=author&query=Hiramatsu%2C+D">Daichi Hiramatsu</a>, <a href="/search/astro-ph?searchtype=author&query=Bostroem%2C+K+A">K. Azalee Bostroem</a>, <a href="/search/astro-ph?searchtype=author&query=Kundu%2C+E">Esha Kundu</a>, <a href="/search/astro-ph?searchtype=author&query=Kuncarayakti%2C+H">Hanindyo Kuncarayakti</a>, <a href="/search/astro-ph?searchtype=author&query=Bersten%2C+M+C">Melina C. Bersten</a>, <a href="/search/astro-ph?searchtype=author&query=Pooley%2C+D">David Pooley</a>, <a href="/search/astro-ph?searchtype=author&query=Lee%2C+S">Shiu-Hang Lee</a>, <a href="/search/astro-ph?searchtype=author&query=Patnaude%2C+D">Daniel Patnaude</a>, <a href="/search/astro-ph?searchtype=author&query=Rodriguez%2C+O">Osmar Rodriguez</a>, <a href="/search/astro-ph?searchtype=author&query=Folatelli%2C+G">Gaston Folatelli</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2211.04808v1-abstract-short" style="display: inline;"> SN 2018ivc is an unusual type II supernova (SN II). It is a variant of SNe IIL, which might represent a transitional case between SNe IIP with a massive H-rich envelope, and IIb with only a small amount of the H-rich envelope. However, SN 2018ivc shows an optical light curve evolution more complicated than canonical SNe IIL. In this paper, we present the results of prompt follow-up observations of… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2211.04808v1-abstract-full').style.display = 'inline'; document.getElementById('2211.04808v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2211.04808v1-abstract-full" style="display: none;"> SN 2018ivc is an unusual type II supernova (SN II). It is a variant of SNe IIL, which might represent a transitional case between SNe IIP with a massive H-rich envelope, and IIb with only a small amount of the H-rich envelope. However, SN 2018ivc shows an optical light curve evolution more complicated than canonical SNe IIL. In this paper, we present the results of prompt follow-up observations of SN 2018ivc with the Atacama Large Millimeter/submillimeter Array (ALMA). Its synchrotron emission is similar to that of SN IIb 1993J, suggesting that it is intrinsically an SN IIb-like explosion of a He star with a modest (~0.5 - 1 Msun) extended H-rich envelope. Its radio, optical, and X-ray light curves are explained primarily by the interaction between the SN ejecta and the circumstellar material (CSM); we thus suggest that it is a rare example (and the first involving the `canonical' SN IIb ejecta) for which the multi-wavelength emission is powered mainly by the SN-CSM interaction. The inner CSM density, reflecting the progenitor activity in the final decade, is comparable to that of SN IIb 2013cu that showed a flash spectral feature. The outer CSM density, and therefore the mass-loss rate in the final ~200 years, is larger than that of SN 1993J by a factor of ~5. We suggest that SN 2018ivc represents a missing link between SNe IIP and IIb/Ib/Ic in the binary evolution scenario. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2211.04808v1-abstract-full').style.display = 'none'; document.getElementById('2211.04808v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 9 November, 2022; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> November 2022. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">31 pages, 14 figures, 3 tables. Accepted for publication in ApJ</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2211.02823">arXiv:2211.02823</a> <span> [<a href="https://arxiv.org/pdf/2211.02823">pdf</a>, <a href="https://arxiv.org/format/2211.02823">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="High Energy Astrophysical Phenomena">astro-ph.HE</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1093/mnras/stac3234">10.1093/mnras/stac3234 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Photometric and spectroscopic analysis of the Type II SN 2020jfo with a short plateau </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Ailawadhi%2C+B">B. Ailawadhi</a>, <a href="/search/astro-ph?searchtype=author&query=Dastidar%2C+R">R. Dastidar</a>, <a href="/search/astro-ph?searchtype=author&query=Misra%2C+K">K. Misra</a>, <a href="/search/astro-ph?searchtype=author&query=Roy%2C+R">R. Roy</a>, <a href="/search/astro-ph?searchtype=author&query=Hiramatsu%2C+D">D. Hiramatsu</a>, <a href="/search/astro-ph?searchtype=author&query=Howell%2C+D+A">D. A. Howell</a>, <a href="/search/astro-ph?searchtype=author&query=Brink%2C+T+G">T. G. Brink</a>, <a href="/search/astro-ph?searchtype=author&query=Zheng%2C+W">W. Zheng</a>, <a href="/search/astro-ph?searchtype=author&query=Galbany%2C+L">L. Galbany</a>, <a href="/search/astro-ph?searchtype=author&query=Shahbandeh%2C+M">M. Shahbandeh</a>, <a href="/search/astro-ph?searchtype=author&query=Arcavi%2C+I">I. Arcavi</a>, <a href="/search/astro-ph?searchtype=author&query=Ashall%2C+C">C. Ashall</a>, <a href="/search/astro-ph?searchtype=author&query=Bostroem%2C+K+A">K. A. Bostroem</a>, <a href="/search/astro-ph?searchtype=author&query=Burke%2C+J">J. Burke</a>, <a href="/search/astro-ph?searchtype=author&query=Chapman%2C+T">T. Chapman</a>, <a href="/search/astro-ph?searchtype=author&query=Dimple"> Dimple</a>, <a href="/search/astro-ph?searchtype=author&query=Filippenko%2C+A+V">A. V. Filippenko</a>, <a href="/search/astro-ph?searchtype=author&query=Gangopadhyay%2C+A">A. Gangopadhyay</a>, <a href="/search/astro-ph?searchtype=author&query=Ghosh%2C+A">A. Ghosh</a>, <a href="/search/astro-ph?searchtype=author&query=Hoffman%2C+A+M">A. M. Hoffman</a>, <a href="/search/astro-ph?searchtype=author&query=Hosseinzadeh%2C+G">G. Hosseinzadeh</a>, <a href="/search/astro-ph?searchtype=author&query=Jennings%2C+C">C. Jennings</a>, <a href="/search/astro-ph?searchtype=author&query=Jha%2C+V+K">V. K. Jha</a>, <a href="/search/astro-ph?searchtype=author&query=Kumar%2C+A">A. Kumar</a>, <a href="/search/astro-ph?searchtype=author&query=Karamehmetoglu%2C+E">E. Karamehmetoglu</a> , et al. (12 additional authors not shown) </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2211.02823v1-abstract-short" style="display: inline;"> We present high-cadence photometric and spectroscopic observations of SN~2020jfo in ultraviolet and optical/near-infrared bands starting from $\sim 3$ to $\sim 434$ days after the explosion, including the earliest data with the 10.4\,m GTC. SN~2020jfo is a hydrogen-rich Type II SN with a relatively short plateau duration ($67.0 \pm 0.6$ days). When compared to other Type II supernovae (SNe) of sim… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2211.02823v1-abstract-full').style.display = 'inline'; document.getElementById('2211.02823v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2211.02823v1-abstract-full" style="display: none;"> We present high-cadence photometric and spectroscopic observations of SN~2020jfo in ultraviolet and optical/near-infrared bands starting from $\sim 3$ to $\sim 434$ days after the explosion, including the earliest data with the 10.4\,m GTC. SN~2020jfo is a hydrogen-rich Type II SN with a relatively short plateau duration ($67.0 \pm 0.6$ days). When compared to other Type II supernovae (SNe) of similar or shorter plateau lengths, SN~2020jfo exhibits a fainter peak absolute $V$-band magnitude ($M_V = -16.90 \pm 0.34$ mag). SN~2020jfo shows significant H$伪$ absorption in the plateau phase similar to that of typical SNe~II. The emission line of stable [Ni~II] $位$7378, mostly seen in low-luminosity SNe~II, is very prominent in the nebular-phase spectra of SN~2020jfo. Using the relative strengths of [Ni~II] $位$7378 and [Fe~II] $位$7155, we derive the Ni/Fe production (abundance) ratio of 0.08--0.10, which is $\sim 1.5$ times the solar value. The progenitor mass of SN~2020jfo from nebular-phase spectral modelling and semi-analytical modelling falls in the range of 12--15\,$M_\odot$. Furthermore, semi-analytical modelling suggests a massive H envelope in the progenitor of SN~2020jfo, which is unlikely for SNe~II having short plateaus. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2211.02823v1-abstract-full').style.display = 'none'; document.getElementById('2211.02823v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 5 November, 2022; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> November 2022. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">20 pages (plus 5 pages appendix), 19 figures, Accepted for publication in MNRAS</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2211.00205">arXiv:2211.00205</a> <span> [<a href="https://arxiv.org/pdf/2211.00205">pdf</a>, <a href="https://arxiv.org/format/2211.00205">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="High Energy Astrophysical Phenomena">astro-ph.HE</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.3847/1538-4357/accddc">10.3847/1538-4357/accddc <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Near-Infrared and Optical Observations of Type Ic SN 2021krf: Luminous Late-time Emission and Dust Formation </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Ravi%2C+A+P">Aravind P. Ravi</a>, <a href="/search/astro-ph?searchtype=author&query=Rho%2C+J">Jeonghee Rho</a>, <a href="/search/astro-ph?searchtype=author&query=Park%2C+S">Sangwook Park</a>, <a href="/search/astro-ph?searchtype=author&query=Park%2C+S+H">Seong Hyun Park</a>, <a href="/search/astro-ph?searchtype=author&query=Yoon%2C+S">Sung-Chul Yoon</a>, <a href="/search/astro-ph?searchtype=author&query=Geballe%2C+T+R">T. R. Geballe</a>, <a href="/search/astro-ph?searchtype=author&query=Vinko%2C+J">Jozsef Vinko</a>, <a href="/search/astro-ph?searchtype=author&query=Tinyanont%2C+S">Samaporn Tinyanont</a>, <a href="/search/astro-ph?searchtype=author&query=Bostroem%2C+K+A">K. Azalee Bostroem</a>, <a href="/search/astro-ph?searchtype=author&query=Burke%2C+J">Jamison Burke</a>, <a href="/search/astro-ph?searchtype=author&query=Hiramatsu%2C+D">Daichi Hiramatsu</a>, <a href="/search/astro-ph?searchtype=author&query=Howell%2C+D+A">D. Andrew Howell</a>, <a href="/search/astro-ph?searchtype=author&query=McCully%2C+C">Curtis McCully</a>, <a href="/search/astro-ph?searchtype=author&query=Newsome%2C+M">Megan Newsome</a>, <a href="/search/astro-ph?searchtype=author&query=Gonzalez%2C+E+P">Estefania Padilla Gonzalez</a>, <a href="/search/astro-ph?searchtype=author&query=Pellegrino%2C+C">Craig Pellegrino</a>, <a href="/search/astro-ph?searchtype=author&query=Cartier%2C+R">Regis Cartier</a>, <a href="/search/astro-ph?searchtype=author&query=Pritchard%2C+T">Tyler Pritchard</a>, <a href="/search/astro-ph?searchtype=author&query=Andersen%2C+M">Morten Andersen</a>, <a href="/search/astro-ph?searchtype=author&query=Blinnikov%2C+S">Sergey Blinnikov</a>, <a href="/search/astro-ph?searchtype=author&query=Dong%2C+Y">Yize Dong</a>, <a href="/search/astro-ph?searchtype=author&query=Blanchard%2C+P">Peter Blanchard</a>, <a href="/search/astro-ph?searchtype=author&query=Kilpatrick%2C+C+D">Charles D. Kilpatrick</a>, <a href="/search/astro-ph?searchtype=author&query=Hoeflich%2C+P">Peter Hoeflich</a>, <a href="/search/astro-ph?searchtype=author&query=Valenti%2C+S">Stefano Valenti</a> , et al. (7 additional authors not shown) </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2211.00205v2-abstract-short" style="display: inline;"> We present near-infrared (NIR) and optical observations of the Type Ic supernova (SN Ic) SN 2021krf obtained between days 13 and 259 at several ground-based telescopes. The NIR spectrum at day 68 exhibits a rising $K$-band continuum flux density longward of $\sim$ 2.0 $渭$m, and a late-time optical spectrum at day 259 shows strong [O I] 6300 and 6364 脜 emission-line asymmetry, both indicating the p… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2211.00205v2-abstract-full').style.display = 'inline'; document.getElementById('2211.00205v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2211.00205v2-abstract-full" style="display: none;"> We present near-infrared (NIR) and optical observations of the Type Ic supernova (SN Ic) SN 2021krf obtained between days 13 and 259 at several ground-based telescopes. The NIR spectrum at day 68 exhibits a rising $K$-band continuum flux density longward of $\sim$ 2.0 $渭$m, and a late-time optical spectrum at day 259 shows strong [O I] 6300 and 6364 脜 emission-line asymmetry, both indicating the presence of dust, likely formed in the SN ejecta. We estimate a carbon-grain dust mass of $\sim$ 2 $\times$ 10$^{-5}$ M$_{\odot}$ and a dust temperature of $\sim$ 900 - 1200 K associated with this rising continuum and suggest the dust has formed in SN ejecta. Utilizing the one-dimensional multigroup radiation hydrodynamics code STELLA, we present two degenerate progenitor solutions for SN 2021krf, characterized by C-O star masses of 3.93 and 5.74 M$_{\odot}$, but with the same best-fit $^{56}$Ni mass of 0.11 M$_{\odot}$ for early times (0-70 days). At late times (70-300 days), optical light curves of SN 2021krf decline substantially more slowly than that expected from $^{56}$Co radioactive decay. Lack of H and He lines in the late-time SN spectrum suggests the absence of significant interaction of the ejecta with the circumstellar medium. We reproduce the entire bolometric light curve with a combination of radioactive decay and an additional powering source in the form of a central engine of a millisecond pulsar with a magnetic field smaller than that of a typical magnetar. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2211.00205v2-abstract-full').style.display = 'none'; document.getElementById('2211.00205v2-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 19 April, 2023; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 31 October, 2022; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> November 2022. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">Accepted for publication in ApJ, 27 pages, 21 figures, 6 tables. Previous arXiv submission (arXiv:2211.00205) replaced after acceptance</span> </p> </li> </ol> <nav class="pagination is-small is-centered breathe-horizontal" role="navigation" aria-label="pagination"> <a href="" class="pagination-previous is-invisible">Previous </a> <a href="/search/?searchtype=author&query=Bostroem%2C+K+A&start=50" class="pagination-next" >Next </a> <ul class="pagination-list"> <li> <a href="/search/?searchtype=author&query=Bostroem%2C+K+A&start=0" class="pagination-link is-current" aria-label="Goto page 1">1 </a> </li> <li> <a href="/search/?searchtype=author&query=Bostroem%2C+K+A&start=50" class="pagination-link " aria-label="Page 2" aria-current="page">2 </a> </li> </ul> </nav> <div class="is-hidden-tablet">  <span class="help" style="display: inline-block;"><a href="https://github.com/arXiv/arxiv-search/releases">Search v0.5.6 released 2020-02-24</a>  </span> </div> </div> </main> <footer> <div class="columns is-desktop" role="navigation" aria-label="Secondary">  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