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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/2405.09175">arXiv:2405.09175</a> <span> [<a href="https://arxiv.org/pdf/2405.09175">pdf</a>, <a href="https://arxiv.org/format/2405.09175">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="General Relativity and Quantum Cosmology">gr-qc</span> </div> </div> <p class="title is-5 mathjax"> Continuum emission from within the plunging region of black hole discs </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Mummery%2C+A">Andrew Mummery</a>, <a href="/search/astro-ph?searchtype=author&query=Ingram%2C+A">Adam Ingram</a>, <a href="/search/astro-ph?searchtype=author&query=Davis%2C+S">Shane Davis</a>, <a href="/search/astro-ph?searchtype=author&query=Fabian%2C+A">Andrew Fabian</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="2405.09175v1-abstract-short" style="display: inline;"> The thermal continuum emission observed from accreting black holes across X-ray bands has the potential to be leveraged as a powerful probe of the mass and spin of the central black hole. The vast majority of existing ``continuum fitting'' models neglect emission sourced at and within the innermost stable circular orbit (ISCO) of the black hole. Numerical simulations, however, find non-zero emissi… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2405.09175v1-abstract-full').style.display = 'inline'; document.getElementById('2405.09175v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2405.09175v1-abstract-full" style="display: none;"> The thermal continuum emission observed from accreting black holes across X-ray bands has the potential to be leveraged as a powerful probe of the mass and spin of the central black hole. The vast majority of existing ``continuum fitting'' models neglect emission sourced at and within the innermost stable circular orbit (ISCO) of the black hole. Numerical simulations, however, find non-zero emission sourced from these regions. In this work we extend existing techniques by including the emission sourced from within the plunging region, utilising new analytical models which reproduce the properties of numerical accretion simulations. We show that in general the neglected intra-ISCO emission produces a hot-and-small quasi-blackbody component, but can also produce a weak power-law tail for more extreme parameter regions. A similar hot-and-small blackbody component has been added in by hand in an ad-hoc manner to previous analyses of X-ray binary spectra. We show that the X-ray spectrum of MAXI J1820+070 in a soft-state outburst is extremely well described by a full Kerr black hole disc, while conventional models which neglect intra-ISCO emission are unable to reproduce the data. We believe this represents the first robust detection of intra-ISCO emission in the literature, and allows additional constraints to be placed on the MAXI J1820+070 black hole spin which must be low $a_\bullet < 0.5$ to allow a detectable intra-ISCO region. Emission from within the ISCO is the dominant emission component in the MAXI J1820+070 spectrum between $6$ and $10$ keV, highlighting the necessity of including this region. Our continuum fitting model is made publicly available. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2405.09175v1-abstract-full').style.display = 'none'; document.getElementById('2405.09175v1-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> 15 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">20 pages, 20 figures, 2 tables. Version to be published in MNRAS. X-ray spectral model available at: https://github.com/andymummeryastro/fullkerr</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2405.08739">arXiv:2405.08739</a> <span> [<a href="https://arxiv.org/pdf/2405.08739">pdf</a>, <a href="https://arxiv.org/format/2405.08739">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> </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/10.1007/s11207-024-02314-x">10.1007/s11207-024-02314-x <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> CATEcor: an Open Science, Shaded-Truss, Externally-Occulted Coronagraph </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=DeForest%2C+C+E">Craig E. DeForest</a>, <a href="/search/astro-ph?searchtype=author&query=Seaton%2C+D+B">Daniel B. Seaton</a>, <a href="/search/astro-ph?searchtype=author&query=Caspi%2C+A">Amir Caspi</a>, <a href="/search/astro-ph?searchtype=author&query=Beasley%2C+M">Matt Beasley</a>, <a href="/search/astro-ph?searchtype=author&query=Davis%2C+S+J">Sarah J. Davis</a>, <a href="/search/astro-ph?searchtype=author&query=Erickson%2C+N+F">Nicholas F. Erickson</a>, <a href="/search/astro-ph?searchtype=author&query=Kovac%2C+S+A">Sarah A. Kovac</a>, <a href="/search/astro-ph?searchtype=author&query=Patel%2C+R">Ritesh Patel</a>, <a href="/search/astro-ph?searchtype=author&query=Tosolini%2C+A">Anna Tosolini</a>, <a href="/search/astro-ph?searchtype=author&query=West%2C+M+J">Matthew J. West</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="2405.08739v1-abstract-short" style="display: inline;"> We present the design of a portable coronagraph, CATEcor, that incorporates a novel "shaded truss" style of external occultation and serves as a proof-of-concept for that family of coronagraphs. The shaded truss design style has the potential for broad application in various scientific settings. We conceived CATEcor itself as a simple instrument to observe the corona during the darker skies availa… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2405.08739v1-abstract-full').style.display = 'inline'; document.getElementById('2405.08739v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2405.08739v1-abstract-full" style="display: none;"> We present the design of a portable coronagraph, CATEcor, that incorporates a novel "shaded truss" style of external occultation and serves as a proof-of-concept for that family of coronagraphs. The shaded truss design style has the potential for broad application in various scientific settings. We conceived CATEcor itself as a simple instrument to observe the corona during the darker skies available during a partial solar eclipse, or for students or interested amateurs to detect the corona under ideal non-eclipsed conditions. CATEcor is therefore optimized for simplicity and accessibility to the public. It is implemented using an existing dioptric telescope and an adapter rig that mounts in front of the objective lens, restricting the telescope aperture and providing external occultation. The adapter rig, including occulter, is fabricated using fusion deposition modeling (FDM; colloquially "3D printing"), greatly reducing cost. The structure is designed to be integrated with moderate care and may be replicated in a university or amateur setting. While CATEcor is a simple demonstration unit, the design concept, process, and trades are useful for other more sophisticated coronagraphs in the same general family, which might operate under normal daytime skies outside the annular-eclipse conditions used for CATEcor. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2405.08739v1-abstract-full').style.display = 'none'; document.getElementById('2405.08739v1-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 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">27pp; 12 figures; accepted to Solar Physics</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Solar Physics, Vol. 299, 78 (23pp); 2024 June 10 </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2404.18446">arXiv:2404.18446</a> <span> [<a href="https://arxiv.org/pdf/2404.18446">pdf</a>, <a href="https://arxiv.org/format/2404.18446">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"> Pre-peak Emission in Tidal Disruption Events </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Huang%2C+X">Xiaoshan Huang</a>, <a href="/search/astro-ph?searchtype=author&query=Davis%2C+S+W">Shane W. Davis</a>, <a href="/search/astro-ph?searchtype=author&query=Jiang%2C+Y">Yan-fei Jiang</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="2404.18446v1-abstract-short" style="display: inline;"> The rising part of a tidal disruption event light curve provides unique insight into early emission and the onset of accretion. Various mechanisms are proposed to explain the pre-peak emission, including shocks from debris interaction and reprocessing of disk emission. We study the pre-peak emission and its influence on the gas circularization by a series of gray radiation hydrodynamic simulations… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2404.18446v1-abstract-full').style.display = 'inline'; document.getElementById('2404.18446v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2404.18446v1-abstract-full" style="display: none;"> The rising part of a tidal disruption event light curve provides unique insight into early emission and the onset of accretion. Various mechanisms are proposed to explain the pre-peak emission, including shocks from debris interaction and reprocessing of disk emission. We study the pre-peak emission and its influence on the gas circularization by a series of gray radiation hydrodynamic simulations with varying black hole mass. We find that given a super-Eddington fallback rate of 10\dot{M}_{Edd}, the stream-stream collision can occur multiple times and drive strong outflows of up to 9\dot{M}_{Edd}. By dispersing gas to \gtrsim 100rs, the outflow can delay gas circularization and leads to sub-Eddington accretion rates during the first few stream-stream collisions. The stream-stream collision shock and circularization shock can sustain a luminosity of ~10^{44}erg/s for days. The luminosity is generally sub-Eddington and shows a weak correlation with accretion rate at early time. The outflow is optically thick, yielding a reprocessing layer with a size of ~10^{14} cm and photospheric temperature of ~4\times10^{4}K. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2404.18446v1-abstract-full').style.display = 'none'; document.getElementById('2404.18446v1-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 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">21 Pages, 19 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/2404.02097">arXiv:2404.02097</a> <span> [<a href="https://arxiv.org/pdf/2404.02097">pdf</a>, <a href="https://arxiv.org/format/2404.02097">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="Instrumentation and Methods for Astrophysics">astro-ph.IM</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/10.1007/s11207-024-02297-9">10.1007/s11207-024-02297-9 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Observations of the Polarized Solar Corona during the Annular Eclipse of October 14, 2023 </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Seaton%2C+D+B">Daniel B. Seaton</a>, <a href="/search/astro-ph?searchtype=author&query=Caspi%2C+A">Amir Caspi</a>, <a href="/search/astro-ph?searchtype=author&query=Alzate%2C+N">Nathalia Alzate</a>, <a href="/search/astro-ph?searchtype=author&query=Davis%2C+S+J">Sarah J. Davis</a>, <a href="/search/astro-ph?searchtype=author&query=DeForest%2C+A+R">Alec R. DeForest</a>, <a href="/search/astro-ph?searchtype=author&query=DeForest%2C+C+E">Craig E. DeForest</a>, <a href="/search/astro-ph?searchtype=author&query=Erickson%2C+N+F">Nicholas F. Erickson</a>, <a href="/search/astro-ph?searchtype=author&query=Kovac%2C+S+A">Sarah A. Kovac</a>, <a href="/search/astro-ph?searchtype=author&query=Patel%2C+R">Ritesh Patel</a>, <a href="/search/astro-ph?searchtype=author&query=Osterman%2C+S+N">Steven N. Osterman</a>, <a href="/search/astro-ph?searchtype=author&query=Tosolini%2C+A">Anna Tosolini</a>, <a href="/search/astro-ph?searchtype=author&query=Van+Kooten%2C+S+J">Samuel J. Van Kooten</a>, <a href="/search/astro-ph?searchtype=author&query=West%2C+M+J">Matthew J. West</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="2404.02097v2-abstract-short" style="display: inline;"> We present results of a dual eclipse expedition to observe the solar corona from two sites during the annular solar eclipse of 2023 October 14, using a novel coronagraph designed to be accessible for amateurs and students to build and deploy. The coronagraph "CATEcor" builds on the standardized eclipse observing equipment developed for the Citizen CATE 2024 experiment. The observing sites were sel… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2404.02097v2-abstract-full').style.display = 'inline'; document.getElementById('2404.02097v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2404.02097v2-abstract-full" style="display: none;"> We present results of a dual eclipse expedition to observe the solar corona from two sites during the annular solar eclipse of 2023 October 14, using a novel coronagraph designed to be accessible for amateurs and students to build and deploy. The coronagraph "CATEcor" builds on the standardized eclipse observing equipment developed for the Citizen CATE 2024 experiment. The observing sites were selected for likelihood of clear observations, for historic relevance (near the Climax site in the Colorado Rocky Mountains), and for centrality to the annular eclipse path (atop Sandia Peak above Albuquerque, New Mexico). The novel portion of CATEcor is an external occulter assembly that slips over the front of a conventional dioptric telescope, forming a "shaded-truss" externally occulted coronagraph. CATEcor is specifically designed to be easily constructed in a garage or "makerspace" environment. We successfully observed some bright features in the solar corona to an altitude of approximately 2.25 R$_\odot$ during the annular phases of the eclipse. Future improvements to the design, in progress now, will reduce both stray light and image artifacts; our objective is to develop a design that can be operated successfully by amateur astronomers at sufficient altitude even without the darkened skies of a partial or annular eclipse. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2404.02097v2-abstract-full').style.display = 'none'; document.getElementById('2404.02097v2-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 April, 2024; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 2 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 by Solar Physics</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Solar Physics, Vol. 299, 79 (20pp); 2024 June 10 </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2401.14474">arXiv:2401.14474</a> <span> [<a href="https://arxiv.org/pdf/2401.14474">pdf</a>, <a href="https://arxiv.org/format/2401.14474">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 NIRSpec+MIRI Observations of the nearby Type IIP supernova 2022acko </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Shahbandeh%2C+M">M. Shahbandeh</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=Fox%2C+O">O. Fox</a>, <a href="/search/astro-ph?searchtype=author&query=Mera%2C+T">T. Mera</a>, <a href="/search/astro-ph?searchtype=author&query=DerKacy%2C+J">J. DerKacy</a>, <a href="/search/astro-ph?searchtype=author&query=Stritzinger%2C+M+D">M. D. Stritzinger</a>, <a href="/search/astro-ph?searchtype=author&query=Shappee%2C+B">B. Shappee</a>, <a href="/search/astro-ph?searchtype=author&query=Law%2C+D">D. Law</a>, <a href="/search/astro-ph?searchtype=author&query=Morrison%2C+J">J. Morrison</a>, <a href="/search/astro-ph?searchtype=author&query=Pauly%2C+T">T. Pauly</a>, <a href="/search/astro-ph?searchtype=author&query=Pierel%2C+J">J. Pierel</a>, <a href="/search/astro-ph?searchtype=author&query=Medler%2C+K">K. Medler</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+A">A. Bostroem</a>, <a href="/search/astro-ph?searchtype=author&query=Brown%2C+P">P. Brown</a>, <a href="/search/astro-ph?searchtype=author&query=Burns%2C+C">C. 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=Cross%2C+D">D. Cross</a>, <a href="/search/astro-ph?searchtype=author&query=Davis%2C+S">S. Davis</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> , et al. (43 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="2401.14474v1-abstract-short" style="display: inline;"> We present JWST spectral and photometric observations of the Type IIP supernova (SN) 2022acko at ~50 days past explosion. These data are the first JWST spectral observations of a core-collapse SN. We identify ~30 different H I features, other features associated with products produced from the CNO cycle, and s-process elements such as Sc II and Ba II. By combining the JWST spectra with ground-base… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2401.14474v1-abstract-full').style.display = 'inline'; document.getElementById('2401.14474v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2401.14474v1-abstract-full" style="display: none;"> We present JWST spectral and photometric observations of the Type IIP supernova (SN) 2022acko at ~50 days past explosion. These data are the first JWST spectral observations of a core-collapse SN. We identify ~30 different H I features, other features associated with products produced from the CNO cycle, and s-process elements such as Sc II and Ba II. By combining the JWST spectra with ground-based optical and NIR spectra, we construct a full Spectral Energy Distribution from 0.4 to 25 microns and find that the JWST spectra are fully consistent with the simultaneous JWST photometry. The data lack signatures of CO formation and we estimate a limit on the CO mass of < 10^{-8} solar mass. We demonstrate how the CO fundamental band limits can be used to probe underlying physics during stellar evolution, explosion, and the environment. The observations indicate little mixing between the H envelope and C/O core in the ejecta and show no evidence of dust. The data presented here set a critical baseline for future JWST observations, where possible molecular and dust formation may be seen. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2401.14474v1-abstract-full').style.display = 'none'; document.getElementById('2401.14474v1-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 January, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> January 2024. </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2312.07490">arXiv:2312.07490</a> <span> [<a href="https://arxiv.org/pdf/2312.07490">pdf</a>, <a href="https://arxiv.org/format/2312.07490">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Popular Physics">physics.pop-ph</span> <span class="tag is-small is-grey 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="Solar and Stellar Astrophysics">astro-ph.SR</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Space Physics">physics.space-ph</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/10.3847/2515-5172/ad0b0d">10.3847/2515-5172/ad0b0d <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> A Chromatic Treatment of Linear Polarization in the Solar Corona at the 2023 Total Solar Eclipse </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Patel%2C+R">Ritesh Patel</a>, <a href="/search/astro-ph?searchtype=author&query=Seaton%2C+D+B">Daniel B. Seaton</a>, <a href="/search/astro-ph?searchtype=author&query=Caspi%2C+A">Amir Caspi</a>, <a href="/search/astro-ph?searchtype=author&query=Kovac%2C+S+A">Sarah A. Kovac</a>, <a href="/search/astro-ph?searchtype=author&query=Davis%2C+S+J">Sarah J. Davis</a>, <a href="/search/astro-ph?searchtype=author&query=Carini%2C+J+P">John P. Carini</a>, <a href="/search/astro-ph?searchtype=author&query=Gardner%2C+C+H">Charles H. Gardner</a>, <a href="/search/astro-ph?searchtype=author&query=Gosain%2C+S">Sanjay Gosain</a>, <a href="/search/astro-ph?searchtype=author&query=Klein%2C+V">Viliam Klein</a>, <a href="/search/astro-ph?searchtype=author&query=Laatsch%2C+S+A">Shawn A. Laatsch</a>, <a href="/search/astro-ph?searchtype=author&query=Reiff%2C+P+H">Patricia H. Reiff</a>, <a href="/search/astro-ph?searchtype=author&query=Saini%2C+N">Nikita Saini</a>, <a href="/search/astro-ph?searchtype=author&query=Weir%2C+R">Rachael Weir</a>, <a href="/search/astro-ph?searchtype=author&query=Zietlow%2C+D+W">Daniel W. Zietlow</a>, <a href="/search/astro-ph?searchtype=author&query=Elmore%2C+D+F">David F. Elmore</a>, <a href="/search/astro-ph?searchtype=author&query=Ursache%2C+A+E">Andrei E. Ursache</a>, <a href="/search/astro-ph?searchtype=author&query=DeForest%2C+C+E">Craig E. DeForest</a>, <a href="/search/astro-ph?searchtype=author&query=West%2C+M+J">Matthew J. West</a>, <a href="/search/astro-ph?searchtype=author&query=Bruenjes%2C+F">Fred Bruenjes</a>, <a href="/search/astro-ph?searchtype=author&query=Winter%2C+J">Jen Winter</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="2312.07490v1-abstract-short" style="display: inline;"> The broadband solar K-corona is linearly polarized due to Thomson scattering. Various strategies have been used to represent coronal polarization. Here, we present a new way to visualize the polarized corona, using observations from the 2023 April 20 total solar eclipse in Australia in support of the Citizen CATE 2024 project. We convert observations in the common four-polarizer orthogonal basis (… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2312.07490v1-abstract-full').style.display = 'inline'; document.getElementById('2312.07490v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2312.07490v1-abstract-full" style="display: none;"> The broadband solar K-corona is linearly polarized due to Thomson scattering. Various strategies have been used to represent coronal polarization. Here, we present a new way to visualize the polarized corona, using observations from the 2023 April 20 total solar eclipse in Australia in support of the Citizen CATE 2024 project. We convert observations in the common four-polarizer orthogonal basis (0掳, 45掳, 90掳, & 135掳) to -60掳, 0掳, and +60掳 (MZP) polarization, which is homologous to R, G, B color channels. The unique image generated provides some sense of how humans might visualize polarization if we could perceive it in the same way we perceive color. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2312.07490v1-abstract-full').style.display = 'none'; document.getElementById('2312.07490v1-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 November, 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">4 pages, 1 figure; accepted for publication in Research Notes of the American Astronomical Society (RNAAS)</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Research Notes of the AAS, Vol. 7, Issue 11, 241; 2023 November </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2311.17278">arXiv:2311.17278</a> <span> [<a href="https://arxiv.org/pdf/2311.17278">pdf</a>, <a href="https://arxiv.org/format/2311.17278">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"> Line Driven Instabilities due to Continuum Radiation Transport in Stellar Winds </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Dyda%2C+S">Sergei Dyda</a>, <a href="/search/astro-ph?searchtype=author&query=Davis%2C+S+W">Shane W. Davis</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="2311.17278v1-abstract-short" style="display: inline;"> We study line driven stellar winds using time-dependent radiation hydrodynamics where the continuum radiation couples to the gas via either a scattering or absorption opacity and there is an additional radiation force due to spectral lines that we model in the Sobolev approximation. We find that in winds with scattering opacities, instabilties tend to be suppressed and the wind reaches a steady st… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2311.17278v1-abstract-full').style.display = 'inline'; document.getElementById('2311.17278v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2311.17278v1-abstract-full" style="display: none;"> We study line driven stellar winds using time-dependent radiation hydrodynamics where the continuum radiation couples to the gas via either a scattering or absorption opacity and there is an additional radiation force due to spectral lines that we model in the Sobolev approximation. We find that in winds with scattering opacities, instabilties tend to be suppressed and the wind reaches a steady state. Winds with absorption opacities are unstable and remain clumpy at late times. Clumps persist because they are continually regenerated in the subcritical part of the flow. Azimuthal gradients in the radial velocity distribution cause a drop in the radial radiation force and provide a mechanism for generating clumps. These clumps form on super-Sobolev scales, but at late times become Sobolev-length sized indicating that our radiation transfer model is breaking down. Inferring the clump distribution at late times therefore requires radiation-hydrodynamic modeling below the Sobolev scale. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2311.17278v1-abstract-full').style.display = 'none'; document.getElementById('2311.17278v1-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> 28 November, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> November 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, 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/2310.18557">arXiv:2310.18557</a> <span> [<a href="https://arxiv.org/pdf/2310.18557">pdf</a>, <a href="https://arxiv.org/format/2310.18557">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"> Time-Dependent AGN Disc Winds I -- X-ray Irradiation </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Dyda%2C+S">Sergei Dyda</a>, <a href="/search/astro-ph?searchtype=author&query=Davis%2C+S+W">Shane W. Davis</a>, <a href="/search/astro-ph?searchtype=author&query=Proga%2C+D">Daniel Proga</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="2310.18557v1-abstract-short" style="display: inline;"> We study AGN line driven disc winds using time-dependent radiation hydrodynamics. The key criterion for determining wind launching is the coupling strength of the UV radiation field via the spectral lines of the gas. The strength of these lines in turn relies crucially on the gas ionization state, determined by the local X-ray intensity. We consider a suite of models where the central ionizing rad… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2310.18557v1-abstract-full').style.display = 'inline'; document.getElementById('2310.18557v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2310.18557v1-abstract-full" style="display: none;"> We study AGN line driven disc winds using time-dependent radiation hydrodynamics. The key criterion for determining wind launching is the coupling strength of the UV radiation field via the spectral lines of the gas. The strength of these lines in turn relies crucially on the gas ionization state, determined by the local X-ray intensity. We consider a suite of models where the central ionizing radiation is affected by scattering, absorption and re-emission by the intervening gas. In a pure attenuation model, the disc launches an episodic wind, as previous studies have shown. Including scattering or re-emission tends to weaken the wind, lowering the mass flux and outflow velocity and if sufficiently dominant, suppressing the outflow entirely. However, the exponential nature of radiative attenuation means only a modest, factor of a few, increase in the absorption cross section can overcome the wind suppression due to scattering and re-emission. We find mass outflow rates of $\sim 20\%$ or more of the assumed inflow rate through the disk, indicating that radiation driven winds may significantly alter the structure of the accretion flow. The winds also supply a large, time-varying column of material above the nominal constant disk scale height, which will determine the geometry of reprocessed emission from the central source. Our results suggest the need for accurate photoionization modeling, radiation transport as well as accretion disc physics, to study their effects on the AGN disc winds <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2310.18557v1-abstract-full').style.display = 'none'; document.getElementById('2310.18557v1-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> 27 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">13 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/2308.01875">arXiv:2308.01875</a> <span> [<a href="https://arxiv.org/pdf/2308.01875">pdf</a>, <a href="https://arxiv.org/format/2308.01875">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Cosmology and Nongalactic Astrophysics">astro-ph.CO</span> </div> </div> <p class="title is-5 mathjax"> Carnegie Supernova Project-I and -II: Measurements of $H_0$ using Cepheid, TRGB, and SBF Distance Calibration to Type Ia Supernovae </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Uddin%2C+S+A">Syed A. Uddin</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=Phillips%2C+M+M">Mark M. Phillips</a>, <a href="/search/astro-ph?searchtype=author&query=Suntzeff%2C+N+B">Nicholas B. Suntzeff</a>, <a href="/search/astro-ph?searchtype=author&query=Freedman%2C+W+L">Wendy L. Freedman</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=Morrell%2C+N">Nidia Morrell</a>, <a href="/search/astro-ph?searchtype=author&query=Hamuy%2C+M">Mario Hamuy</a>, <a href="/search/astro-ph?searchtype=author&query=Krisciunas%2C+K">Kevin Krisciunas</a>, <a href="/search/astro-ph?searchtype=author&query=Wang%2C+L">Lifan Wang</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=Goobar%2C+A">Ariel Goobar</a>, <a href="/search/astro-ph?searchtype=author&query=Perlmutter%2C+S">Saul Perlmutter</a>, <a href="/search/astro-ph?searchtype=author&query=Lu%2C+J">Jing Lu</a>, <a href="/search/astro-ph?searchtype=author&query=Stritzinger%2C+M">Maximilian Stritzinger</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=Hoeflich%2C+P">Peter Hoeflich</a>, <a href="/search/astro-ph?searchtype=author&query=Shappee%2C+B+J">Benjamin J. Shappee</a>, <a href="/search/astro-ph?searchtype=author&query=Persson%2C+S+E">S. E. Persson</a>, <a href="/search/astro-ph?searchtype=author&query=Piro%2C+A+L">Anthony L. Piro</a>, <a href="/search/astro-ph?searchtype=author&query=Baron%2C+E">Eddie Baron</a>, <a href="/search/astro-ph?searchtype=author&query=Contreras%2C+C">Carlos Contreras</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=Kumar%2C+S">Sahana Kumar</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="2308.01875v2-abstract-short" style="display: inline;"> We present an analysis of Type Ia Supernovae (SNe~Ia) from both the Carnegie Supernova Project~I (CSP-I) and II (CSP-II), and extend the Hubble diagram from the optical to the near-infrared wavelengths ($uBgVriYJH$). We calculate the Hubble constant, $H_0$, using various distance calibrators: Cepheids, Tip of the Red Giant Branch (TRGB), and Surface Brightness Fluctuations (SBF). Combining all met… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2308.01875v2-abstract-full').style.display = 'inline'; document.getElementById('2308.01875v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2308.01875v2-abstract-full" style="display: none;"> We present an analysis of Type Ia Supernovae (SNe~Ia) from both the Carnegie Supernova Project~I (CSP-I) and II (CSP-II), and extend the Hubble diagram from the optical to the near-infrared wavelengths ($uBgVriYJH$). We calculate the Hubble constant, $H_0$, using various distance calibrators: Cepheids, Tip of the Red Giant Branch (TRGB), and Surface Brightness Fluctuations (SBF). Combining all methods of calibrations, we derive $\rm H_0=71.76 \pm 0.58 \ (stat) \pm 1.19 \ (sys) \ km \ s^{-1} \ Mpc^{-1}$ from $B$-band, and $\rm H_0=73.22 \pm 0.68 \ (stat) \pm 1.28 \ (sys) \ km \ s^{-1} \ Mpc^{-1}$ from $H$-band. By assigning equal weight to the Cepheid, TRGB, and SBF calibrators, we derive the systematic errors required for consistency in the first rung of the distance ladder, resulting in a systematic error of $1.2\sim 1.3 \rm \ km \ s^{-1} \ Mpc^{-1}$ in $H_0$. As a result, relative to the statistics-only uncertainty, the tension between the late-time $H_0$ we derive by combining the various distance calibrators and the early-time $H_0$ from the Cosmic Microwave Background is reduced. The highest precision in SN~Ia luminosity is found in the $Y$ band ($0.12\pm0.01$ mag), as defined by the intrinsic scatter ($蟽_{int}$). We revisit SN~Ia Hubble residual-host mass correlations and recover previous results that these correlations do not change significantly between the optical and the near-infrared wavelengths. Finally, SNe~Ia that explode beyond 10 kpc from their host centers exhibit smaller dispersion in their luminosity, confirming our earlier findings. Reduced effect of dust in the outskirt of hosts may be responsible for this effect. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2308.01875v2-abstract-full').style.display = 'none'; document.getElementById('2308.01875v2-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> 24 October, 2023; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 3 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">Revised calculations are made. Will be resubmitted 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/2307.08973">arXiv:2307.08973</a> <span> [<a href="https://arxiv.org/pdf/2307.08973">pdf</a>, <a href="https://arxiv.org/format/2307.08973">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/10.1051/0004-6361/202346511">10.1051/0004-6361/202346511 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Spin measurement of 4U 1543-47 with Insight-HXMT and NICER from its 2021 outburst: A test of accretion disk models at high luminosities </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Yorgancioglu%2C+E+S">E. S. Yorgancioglu</a>, <a href="/search/astro-ph?searchtype=author&query=Bu%2C+Q+C">Q. C. Bu</a>, <a href="/search/astro-ph?searchtype=author&query=Santangelo%2C+A">A. Santangelo</a>, <a href="/search/astro-ph?searchtype=author&query=Tao%2C+L">L. Tao</a>, <a href="/search/astro-ph?searchtype=author&query=Davis%2C+S+W">S. W. Davis</a>, <a href="/search/astro-ph?searchtype=author&query=Vahdat%2C+A">A. Vahdat</a>, <a href="/search/astro-ph?searchtype=author&query=Kong%2C+L+D">L. D. Kong</a>, <a href="/search/astro-ph?searchtype=author&query=Piraino%2C+S">S. Piraino</a>, <a href="/search/astro-ph?searchtype=author&query=Zhou%2C+M">M. Zhou</a>, <a href="/search/astro-ph?searchtype=author&query=Zhang%2C+S+N">S. N. Zhang</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="2307.08973v2-abstract-short" style="display: inline;"> 4U 1543--47 is one of a handful of known black hole candidates located in the Milky Way Galaxy, and has undergone a very bright outburst in 2021, reaching a total of $\sim$9 Crab, as observed by the Monitor of All-sky Image (MAXI), and exceeding twice its Eddington luminosity. The unprecedented bright outburst of 4U 1543--47 provides a unique opportunity to test the behavior of accretion disk mode… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2307.08973v2-abstract-full').style.display = 'inline'; document.getElementById('2307.08973v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2307.08973v2-abstract-full" style="display: none;"> 4U 1543--47 is one of a handful of known black hole candidates located in the Milky Way Galaxy, and has undergone a very bright outburst in 2021, reaching a total of $\sim$9 Crab, as observed by the Monitor of All-sky Image (MAXI), and exceeding twice its Eddington luminosity. The unprecedented bright outburst of 4U 1543--47 provides a unique opportunity to test the behavior of accretion disk models at high luminosities and accretion rates. In addition, we explore the possibility of constraining the spin of the source at high accretion rates, given that previous spin measurements of 4U 1543--47 have been largely inconsistent with each other. We measure the spectral evolution of the source throughout its outburst as observed by Insight-HXMT, and compare the behavior of both the thin disk model kerrbb2, as well as the slim disk model slimbh up to the Eddington limit for two different values of disk $伪$-viscosity. In addition, given the behavior of these two models, we identify two `golden' epochs for which it is most suitable to measure the spin with continuum fitting. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2307.08973v2-abstract-full').style.display = 'none'; document.getElementById('2307.08973v2-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> 21 July, 2023; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 18 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, 6 figures</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> A&A 677, A79 (2023) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2304.07977">arXiv:2304.07977</a> <span> [<a href="https://arxiv.org/pdf/2304.07977">pdf</a>, <a href="https://arxiv.org/format/2304.07977">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"> Spectral calculations of 3D RMHD simulations of super-Eddington accretion onto a stellar-mass black hole </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Mills%2C+B+S">Brianna S. Mills</a>, <a href="/search/astro-ph?searchtype=author&query=Davis%2C+S+W">Shane W. Davis</a>, <a href="/search/astro-ph?searchtype=author&query=Jiang%2C+Y">Yan-Fei Jiang</a>, <a href="/search/astro-ph?searchtype=author&query=Middleton%2C+M+J">Matthew J. Middleton</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="2304.07977v1-abstract-short" style="display: inline;"> We use the Athena++ Monte Carlo (MC) radiation transfer module to post-process simulation snapshots from non-relativistic Athena++ radiation magnetohydrodynamic (RMHD) simulations. These simulations were run using a gray (frequency integrated) approach but were also restarted and ran with a multi-group approach that accounts for Compton scattering with a Kompaneets operator. These simulations prod… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2304.07977v1-abstract-full').style.display = 'inline'; document.getElementById('2304.07977v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2304.07977v1-abstract-full" style="display: none;"> We use the Athena++ Monte Carlo (MC) radiation transfer module to post-process simulation snapshots from non-relativistic Athena++ radiation magnetohydrodynamic (RMHD) simulations. These simulations were run using a gray (frequency integrated) approach but were also restarted and ran with a multi-group approach that accounts for Compton scattering with a Kompaneets operator. These simulations produced moderately super-Eddington accretion rates onto a 6.62 $M_\odot$ black hole. Since we only achieve inflow equilibrium out to 20-25 gravitational radii, we focus on the hard X-ray emission. We provide a comparison between the MC and RMHD simulations showing that the treatment of Compton scattering in the gray RMHD simulations underestimates the gas temperature in the regions above and below the accretion disk. In contrast, the restarted multi-group snapshots provides a treatment for the radiation field that is more consistent with the MC calculations, and result in post-processed spectra with harder X-ray emission compared to their gray snapshot counterparts. We characterize these MC post-processed spectra using commonly employed phenomenological models used for spectral fitting. We also attempt to fit our MC spectra directly to observations of the ultraluminous X-ray source (ULX) NGC 1313 X-1, finding best fit values that are competitive to phenomenological model fits, indicating that first principle models of super-Eddington accretion may adequately explain the observed hard X-ray spectra in some ULX sources. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2304.07977v1-abstract-full').style.display = 'none'; document.getElementById('2304.07977v1-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> 16 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">Submitted to ApJ; 20 pages, 15 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/2304.04869">arXiv:2304.04869</a> <span> [<a href="https://arxiv.org/pdf/2304.04869">pdf</a>, <a href="https://arxiv.org/format/2304.04869">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> </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/10.1088/1538-3873/acd1b5">10.1088/1538-3873/acd1b5 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> The James Webb Space Telescope Mission </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Gardner%2C+J+P">Jonathan P. Gardner</a>, <a href="/search/astro-ph?searchtype=author&query=Mather%2C+J+C">John C. Mather</a>, <a href="/search/astro-ph?searchtype=author&query=Abbott%2C+R">Randy Abbott</a>, <a href="/search/astro-ph?searchtype=author&query=Abell%2C+J+S">James S. Abell</a>, <a href="/search/astro-ph?searchtype=author&query=Abernathy%2C+M">Mark Abernathy</a>, <a href="/search/astro-ph?searchtype=author&query=Abney%2C+F+E">Faith E. Abney</a>, <a href="/search/astro-ph?searchtype=author&query=Abraham%2C+J+G">John G. Abraham</a>, <a href="/search/astro-ph?searchtype=author&query=Abraham%2C+R">Roberto Abraham</a>, <a href="/search/astro-ph?searchtype=author&query=Abul-Huda%2C+Y+M">Yasin M. Abul-Huda</a>, <a href="/search/astro-ph?searchtype=author&query=Acton%2C+S">Scott Acton</a>, <a href="/search/astro-ph?searchtype=author&query=Adams%2C+C+K">Cynthia K. Adams</a>, <a href="/search/astro-ph?searchtype=author&query=Adams%2C+E">Evan Adams</a>, <a href="/search/astro-ph?searchtype=author&query=Adler%2C+D+S">David S. Adler</a>, <a href="/search/astro-ph?searchtype=author&query=Adriaensen%2C+M">Maarten Adriaensen</a>, <a href="/search/astro-ph?searchtype=author&query=Aguilar%2C+J+A">Jonathan Albert Aguilar</a>, <a href="/search/astro-ph?searchtype=author&query=Ahmed%2C+M">Mansoor Ahmed</a>, <a href="/search/astro-ph?searchtype=author&query=Ahmed%2C+N+S">Nasif S. Ahmed</a>, <a href="/search/astro-ph?searchtype=author&query=Ahmed%2C+T">Tanjira Ahmed</a>, <a href="/search/astro-ph?searchtype=author&query=Albat%2C+R">R眉deger Albat</a>, <a href="/search/astro-ph?searchtype=author&query=Albert%2C+L">Lo茂c Albert</a>, <a href="/search/astro-ph?searchtype=author&query=Alberts%2C+S">Stacey Alberts</a>, <a href="/search/astro-ph?searchtype=author&query=Aldridge%2C+D">David Aldridge</a>, <a href="/search/astro-ph?searchtype=author&query=Allen%2C+M+M">Mary Marsha Allen</a>, <a href="/search/astro-ph?searchtype=author&query=Allen%2C+S+S">Shaune S. Allen</a>, <a href="/search/astro-ph?searchtype=author&query=Altenburg%2C+M">Martin Altenburg</a> , et al. (983 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="2304.04869v1-abstract-short" style="display: inline;"> Twenty-six years ago a small committee report, building on earlier studies, expounded a compelling and poetic vision for the future of astronomy, calling for an infrared-optimized space telescope with an aperture of at least $4m$. With the support of their governments in the US, Europe, and Canada, 20,000 people realized that vision as the $6.5m$ James Webb Space Telescope. A generation of astrono… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2304.04869v1-abstract-full').style.display = 'inline'; document.getElementById('2304.04869v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2304.04869v1-abstract-full" style="display: none;"> Twenty-six years ago a small committee report, building on earlier studies, expounded a compelling and poetic vision for the future of astronomy, calling for an infrared-optimized space telescope with an aperture of at least $4m$. With the support of their governments in the US, Europe, and Canada, 20,000 people realized that vision as the $6.5m$ James Webb Space Telescope. A generation of astronomers will celebrate their accomplishments for the life of the mission, potentially as long as 20 years, and beyond. This report and the scientific discoveries that follow are extended thank-you notes to the 20,000 team members. The telescope is working perfectly, with much better image quality than expected. In this and accompanying papers, we give a brief history, describe the observatory, outline its objectives and current observing program, and discuss the inventions and people who made it possible. We cite detailed reports on the design and the measured performance on orbit. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2304.04869v1-abstract-full').style.display = 'none'; document.getElementById('2304.04869v1-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 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">Accepted by PASP for the special issue on The James Webb Space Telescope Overview, 29 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/2303.17443">arXiv:2303.17443</a> <span> [<a href="https://arxiv.org/pdf/2303.17443">pdf</a>, <a href="https://arxiv.org/format/2303.17443">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/ace0be">10.3847/1538-4357/ace0be <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> A Bright First Day for Tidal Disruption Event </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Huang%2C+X">Xiaoshan Huang</a>, <a href="/search/astro-ph?searchtype=author&query=Davis%2C+S+W">Shane W. Davis</a>, <a href="/search/astro-ph?searchtype=author&query=Jiang%2C+Y">Yan-fei Jiang</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="2303.17443v2-abstract-short" style="display: inline;"> Stream-stream collision may be an important pre-peak energy dissipation mechanism in tidal disruption events (TDEs). We perform local three-dimensional radiation hydrodynamic simulations in a wedge geometry including the gravity to study stream self-crossing, with emphasis on resolving the collision and following the subsequent outflow. We find that the collision can contribute to pre-peak optical… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2303.17443v2-abstract-full').style.display = 'inline'; document.getElementById('2303.17443v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2303.17443v2-abstract-full" style="display: none;"> Stream-stream collision may be an important pre-peak energy dissipation mechanism in tidal disruption events (TDEs). We perform local three-dimensional radiation hydrodynamic simulations in a wedge geometry including the gravity to study stream self-crossing, with emphasis on resolving the collision and following the subsequent outflow. We find that the collision can contribute to pre-peak optical emissions by converting $\gtrsim5\%$ of stream kinetic energy to radiation, yielding prompt emission of $\sim10^{42-44}\rm erg~s^{-1}$. The radiative efficiency is sensitive to stream mass fallback rates, and strongly depends on the downstream gas optical depth. Even for a sub-Eddington ($10\%$) mass fallback rate, the strong radiation pressure produced in the collision can form a local super-Eddington region near the collision site, where a fast, aspherical outflow is launched. Higher mass fallback rate usually leads to more optically-thick outflow and lower net radiative efficiency. For $\dot{M}\gtrsim0.1\dot{M}_{\rm Edd}$, the estimated photosphere size of the outflow can expand by one to two orders of magnitudes reaching $\sim10^{14}\rm cm$. The average gas temperature at this photospheric surface is a few $\times10^{4}$K, roughly consistent with inferred pre-peak photosphere properties for some optical TDEs. We find that the dynamics is sensitive to collision angle and collision radius, but the radiative efficiency or outflow properties show more complex dependency than is often assumed in ballistic models. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2303.17443v2-abstract-full').style.display = 'none'; document.getElementById('2303.17443v2-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 July, 2023; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 30 March, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> March 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, Submitted to ApJ. Comments are welcomed and appreciated!</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2302.04283">arXiv:2302.04283</a> <span> [<a href="https://arxiv.org/pdf/2302.04283">pdf</a>, <a href="https://arxiv.org/format/2302.04283">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="Instrumentation and Methods for Astrophysics">astro-ph.IM</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="General Relativity and Quantum Cosmology">gr-qc</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/acc8cf">10.3847/1538-4357/acc8cf <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> An Extension of the Athena++ Code Framework for Radiation-Magnetohydrodynamics in General Relativity Using a Finite-Solid-Angle Discretization </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=White%2C+C+J">Christopher J. White</a>, <a href="/search/astro-ph?searchtype=author&query=Mullen%2C+P+D">Patrick D. Mullen</a>, <a href="/search/astro-ph?searchtype=author&query=Jiang%2C+Y">Yan-Fei Jiang</a>, <a href="/search/astro-ph?searchtype=author&query=Davis%2C+S+W">Shane W. Davis</a>, <a href="/search/astro-ph?searchtype=author&query=Stone%2C+J+M">James M. Stone</a>, <a href="/search/astro-ph?searchtype=author&query=Morozova%2C+V">Viktoriya Morozova</a>, <a href="/search/astro-ph?searchtype=author&query=Zhang%2C+L">Lizhong Zhang</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="2302.04283v2-abstract-short" style="display: inline;"> We extend the general-relativistic magnetohydrodynamics (GRMHD) capabilities of Athena++ to incorporate radiation. The intensity field in each finite-volume cell is discretized in angle, with explicit transport in both space and angle properly accounting for the effects of gravity on null geodesics, and with matter and radiation coupled in a locally implicit fashion. Here we describe the numerical… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2302.04283v2-abstract-full').style.display = 'inline'; document.getElementById('2302.04283v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2302.04283v2-abstract-full" style="display: none;"> We extend the general-relativistic magnetohydrodynamics (GRMHD) capabilities of Athena++ to incorporate radiation. The intensity field in each finite-volume cell is discretized in angle, with explicit transport in both space and angle properly accounting for the effects of gravity on null geodesics, and with matter and radiation coupled in a locally implicit fashion. Here we describe the numerical procedure in detail, verifying its correctness with a suite of tests. Motivated in particular by black hole accretion in the high-accretion-rate, thin-disk regime, we demonstrate the application of the method to this problem. With excellent scaling on flagship computing clusters, the port of the algorithm to the GPU-enabled AthenaK code now allows the simulation of many previously intractable radiation-GRMHD systems. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2302.04283v2-abstract-full').style.display = 'none'; document.getElementById('2302.04283v2-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> 28 March, 2023; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 8 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">To be published in ApJS</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Report number:</span> LA-UR-23-21167 </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2301.12679">arXiv:2301.12679</a> <span> [<a href="https://arxiv.org/pdf/2301.12679">pdf</a>, <a href="https://arxiv.org/format/2301.12679">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/acb6fc">10.3847/1538-4357/acb6fc <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Global Three-Dimensional Radiation Magnetohydrodynamic Simulations of Accretion onto a Stellar Mass Black Hole at Sub- and Near-critical Accretion Rates </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Huang%2C+J">Jiahui Huang</a>, <a href="/search/astro-ph?searchtype=author&query=Jiang%2C+Y">Yan-Fei Jiang</a>, <a href="/search/astro-ph?searchtype=author&query=Feng%2C+H">Hua Feng</a>, <a href="/search/astro-ph?searchtype=author&query=Davis%2C+S+W">Shane W. Davis</a>, <a href="/search/astro-ph?searchtype=author&query=Stone%2C+J+M">James M. Stone</a>, <a href="/search/astro-ph?searchtype=author&query=Middleton%2C+M+J">Matthew J. Middleton</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="2301.12679v1-abstract-short" style="display: inline;"> We present global 3D radiation magnetohydrodynamical simulations of accretion onto a 6.62 solar mass black hole with quasi-steady state accretion rates reaching 0.016 to 0.9 times the critical accretion rate, which is defined as the accretion rate to power the Eddington luminosity assuming a 10% radiative efficiency, in different runs. The simulations show no sign of thermal instability over hundr… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2301.12679v1-abstract-full').style.display = 'inline'; document.getElementById('2301.12679v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2301.12679v1-abstract-full" style="display: none;"> We present global 3D radiation magnetohydrodynamical simulations of accretion onto a 6.62 solar mass black hole with quasi-steady state accretion rates reaching 0.016 to 0.9 times the critical accretion rate, which is defined as the accretion rate to power the Eddington luminosity assuming a 10% radiative efficiency, in different runs. The simulations show no sign of thermal instability over hundreds of thermal timescales at 10 $r_{\rm g}$. The energy dissipation happens close to the mid-plane in the near-critical runs and near the disk surface in the low accretion rate run. The total radiative luminosity inside $\sim$20 $r_{\rm g}$ is about 1% to 30% the Eddington limit, with a radiative efficiency of about 6% and 3%, respectively, in the sub- and near-critical accretion regimes. In both cases, self-consistent turbulence generated by the magnetorotational instability (MRI) leads to angular momentum transfer, and the disk is supported by magnetic pressure. Outflows from the central low-density funnel with a terminal velocity of $\sim$0.1$c$ are seen only in the near-critical runs. We conclude that these magnetic pressure dominated disks are thermally stable and thicker than the $伪$ disk, and the effective temperature profiles are much flatter than that in the $伪$ disks. The magnetic pressure of these disks are comparable within an order of magnitude with the previous analytical magnetic pressure dominated disk model. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2301.12679v1-abstract-full').style.display = 'none'; document.getElementById('2301.12679v1-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> 30 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">17 pages, 13 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/2211.05998">arXiv:2211.05998</a> <span> [<a href="https://arxiv.org/pdf/2211.05998">pdf</a>, <a href="https://arxiv.org/format/2211.05998">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/acc100">10.3847/1538-4357/acc100 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Carnegie Supernova Project-II: Near-infrared spectral diversity and template of Type Ia Supernovae </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Lu%2C+J">Jing Lu</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=Phillips%2C+M+M">Mark M. Phillips</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=Ashall%2C+C">Chris Ashall</a>, <a href="/search/astro-ph?searchtype=author&query=Morrell%2C+N">Nidia Morrell</a>, <a href="/search/astro-ph?searchtype=author&query=Ng%2C+L">Lawrence Ng</a>, <a href="/search/astro-ph?searchtype=author&query=Kumar%2C+S">Sahana Kumar</a>, <a href="/search/astro-ph?searchtype=author&query=Shahbandeh%2C+M">Melissa Shahbandeh</a>, <a href="/search/astro-ph?searchtype=author&query=Hoeflich%2C+P">Peter Hoeflich</a>, <a href="/search/astro-ph?searchtype=author&query=Baron%2C+E">E. Baron</a>, <a href="/search/astro-ph?searchtype=author&query=Uddin%2C+S">Syed Uddin</a>, <a href="/search/astro-ph?searchtype=author&query=Stritzinger%2C+M+D">Maximilian D. Stritzinger</a>, <a href="/search/astro-ph?searchtype=author&query=Suntzeff%2C+N+B">Nicholas B. Suntzeff</a>, <a href="/search/astro-ph?searchtype=author&query=Baltay%2C+C">Charles Baltay</a>, <a href="/search/astro-ph?searchtype=author&query=Davis%2C+S">Scott Davis</a>, <a href="/search/astro-ph?searchtype=author&query=Diamond%2C+T+R">Tiara R. Diamond</a>, <a href="/search/astro-ph?searchtype=author&query=Folatelli%2C+G">Gaston Folatelli</a>, <a href="/search/astro-ph?searchtype=author&query=F%C3%B6rster%2C+F">Francisco F枚rster</a>, <a href="/search/astro-ph?searchtype=author&query=Gagn%C3%A9%2C+J">Jonathan Gagn茅</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=Gall%2C+C">Christa Gall</a>, <a href="/search/astro-ph?searchtype=author&query=Gonz%C3%A1lez-Gait%C3%A1n%2C+S">Santiago Gonz谩lez-Gait谩n</a>, <a href="/search/astro-ph?searchtype=author&query=Holmbo%2C+S">Simon Holmbo</a>, <a href="/search/astro-ph?searchtype=author&query=Kirshner%2C+R+P">Robert P. Kirshner</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="2211.05998v2-abstract-short" style="display: inline;"> We present the largest and most homogeneous collection of near-infrared (NIR) spectra of Type Ia supernovae (SNe Ia): 339 spectra of 98 individual SNe obtained as part of the Carnegie Supernova Project-II. These spectra, obtained with the FIRE spectrograph on the 6.5 m Magellan Baade telescope, have a spectral range of 0.8--2.5 $渭$m. Using this sample, we explore the NIR spectral diversity of SNe… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2211.05998v2-abstract-full').style.display = 'inline'; document.getElementById('2211.05998v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2211.05998v2-abstract-full" style="display: none;"> We present the largest and most homogeneous collection of near-infrared (NIR) spectra of Type Ia supernovae (SNe Ia): 339 spectra of 98 individual SNe obtained as part of the Carnegie Supernova Project-II. These spectra, obtained with the FIRE spectrograph on the 6.5 m Magellan Baade telescope, have a spectral range of 0.8--2.5 $渭$m. Using this sample, we explore the NIR spectral diversity of SNe Ia and construct a template of spectral time series as a function of the light-curve-shape parameter, color stretch $s_{BV}$. Principal component analysis is applied to characterize the diversity of the spectral features and reduce data dimensionality to a smaller subspace. Gaussian process regression is then used to model the subspace dependence on phase and light-curve shape and the associated uncertainty. Our template is able to predict spectral variations that are correlated with $s_{BV}$, such as the hallmark NIR features: Mg II at early times and the $H$-band break after peak. Using this template reduces the systematic uncertainties in K-corrections by ~90% compared to those from the Hsiao template. These uncertainties, defined as the mean K-correction differences computed with the color-matched template and observed spectra, are on the level of $4\times10^{-4}$ mag on average. This template can serve as the baseline spectral energy distribution for light-curve fitters and can identify peculiar spectral features that might point to compelling physics. The results presented here will substantially improve future SN~Ia cosmological experiments, for both nearby and distant samples. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2211.05998v2-abstract-full').style.display = 'none'; document.getElementById('2211.05998v2-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 March, 2023; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 10 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">38 pages, 21 figures, accepted 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/2210.06993">arXiv:2210.06993</a> <span> [<a href="https://arxiv.org/pdf/2210.06993">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/10.3847/1538-4357/acad73">10.3847/1538-4357/acad73 <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 Nebular-phase Spectra of Type Ia Supernovae SN 2013aa and SN 2017cbv in NGC 5643 </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Kumar%2C+S">Sahana Kumar</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=Ashall%2C+C">Chris Ashall</a>, <a href="/search/astro-ph?searchtype=author&query=Phillips%2C+M+M">Mark M. Phillips</a>, <a href="/search/astro-ph?searchtype=author&query=Morrell%2C+N">Nidia Morrell</a>, <a href="/search/astro-ph?searchtype=author&query=Hoeflich%2C+P">Peter Hoeflich</a>, <a href="/search/astro-ph?searchtype=author&query=Burns%2C+C+R">Chris R. Burns</a>, <a href="/search/astro-ph?searchtype=author&query=Galbany%2C+L">Lluis Galbany</a>, <a href="/search/astro-ph?searchtype=author&query=Baron%2C+E">Eddie Baron</a>, <a href="/search/astro-ph?searchtype=author&query=Contreras%2C+C">Carlos Contreras</a>, <a href="/search/astro-ph?searchtype=author&query=Davis%2C+S">Scott Davis</a>, <a href="/search/astro-ph?searchtype=author&query=Diamond%2C+T">Tiara Diamond</a>, <a href="/search/astro-ph?searchtype=author&query=Forster%2C+F">Francisco Forster</a>, <a href="/search/astro-ph?searchtype=author&query=Graham%2C+M+L">Melissa L. Graham</a>, <a href="/search/astro-ph?searchtype=author&query=Karamehmetoglu%2C+E">Emir Karamehmetoglu</a>, <a href="/search/astro-ph?searchtype=author&query=Kirshner%2C+R+P">Robert P. Kirshner</a>, <a href="/search/astro-ph?searchtype=author&query=Koribalski%2C+B">Baerbel Koribalski</a>, <a href="/search/astro-ph?searchtype=author&query=Krisciunas%2C+K">Kevin Krisciunas</a>, <a href="/search/astro-ph?searchtype=author&query=Lu%2C+J">Jing Lu</a>, <a href="/search/astro-ph?searchtype=author&query=Marion%2C+G+H">G. H. Marion</a>, <a href="/search/astro-ph?searchtype=author&query=Pessi%2C+P+J">Priscila J. Pessi</a>, <a href="/search/astro-ph?searchtype=author&query=Piro%2C+A+L">Anthony L. Piro</a>, <a href="/search/astro-ph?searchtype=author&query=Shahbandeh%2C+M">Melissa Shahbandeh</a>, <a href="/search/astro-ph?searchtype=author&query=Stritzinger%2C+M+D">Maximillian D Stritzinger</a>, <a href="/search/astro-ph?searchtype=author&query=Suntzeff%2C+N+B">Nicholas B. Suntzeff</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="2210.06993v2-abstract-short" style="display: inline;"> We present multi-wavelength time-series spectroscopy of SN 2013aa and SN 2017cbv, two Type Ia supernovae (SNe Ia) on the outskirts of the same host galaxy, NGC 5643. This work utilizes new nebular-phase near-infrared (NIR) spectra obtained by the Carnegie Supernova Project-II, in addition to previously published optical and NIR spectra. By measuring nebular-phase [Fe II] lines in both the optical… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2210.06993v2-abstract-full').style.display = 'inline'; document.getElementById('2210.06993v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2210.06993v2-abstract-full" style="display: none;"> We present multi-wavelength time-series spectroscopy of SN 2013aa and SN 2017cbv, two Type Ia supernovae (SNe Ia) on the outskirts of the same host galaxy, NGC 5643. This work utilizes new nebular-phase near-infrared (NIR) spectra obtained by the Carnegie Supernova Project-II, in addition to previously published optical and NIR spectra. By measuring nebular-phase [Fe II] lines in both the optical and NIR, we examine the explosion kinematics and test the efficacy of several emission line fitting techniques commonly used in the literature. The NIR [Fe II] 1.644 $渭$m line provides the most robust velocity measurements against variations due to the choice of the fit method and line blending. The resulting effects on velocity measurements due to choosing different fit methods, initial fit parameters, continuum and line profile functions, and fit region boundaries were also investigated. The NIR [Fe II] velocities yield the same radial shift direction as velocities measured using the optical [Fe II] 7155 A line, but the sizes of the shifts are consistently and substantially lower, pointing to a potential issue in optical studies. The NIR [Fe II] 1.644 $渭$m emission profile shows a lack of significant asymmetry in both SNe Ia, and the observed low velocities elevate the importance for correcting for any radial velocity contribution from the host galaxy's rotation. The low [Fe II] velocities measured in the NIR at nebular phases disfavors most progenitor scenarios in close double-degenerate systems for both SN 2013aa and SN 2017cbv. The time evolution of the NIR [Fe II] 1.644 $渭$m line also indicates moderately high progenitor white dwarf central density and potentially high magnetic fields. These sibling SNe Ia were well observed at both early and late times, providing an excellent opportunity to study the intrinsic diversity of SNe Ia. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2210.06993v2-abstract-full').style.display = 'none'; document.getElementById('2210.06993v2-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 March, 2023; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 11 October, 2022; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> October 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">submitted to ApJ on Oct 4, 2022 accepted for publication on Dec 19, 2022</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2207.04269">arXiv:2207.04269</a> <span> [<a href="https://arxiv.org/pdf/2207.04269">pdf</a>, <a href="https://arxiv.org/ps/2207.04269">ps</a>, <a href="https://arxiv.org/format/2207.04269">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> </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/ac8006">10.3847/1538-4357/ac8006 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Ice Age : Chemo-dynamical modeling of Cha-MMS1 to predict new solid-phase species for detection with JWST </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Jin%2C+M">Mihwa Jin</a>, <a href="/search/astro-ph?searchtype=author&query=Lam%2C+K+H">Ka Ho Lam</a>, <a href="/search/astro-ph?searchtype=author&query=McClure%2C+M+K">Melissa K. McClure</a>, <a href="/search/astro-ph?searchtype=author&query=van+Scheltinga%2C+J+T">Jeroen Terwisscha van Scheltinga</a>, <a href="/search/astro-ph?searchtype=author&query=Li%2C+Z">Zhi-Yun Li</a>, <a href="/search/astro-ph?searchtype=author&query=Boogert%2C+A">Adwin Boogert</a>, <a href="/search/astro-ph?searchtype=author&query=Herbst%2C+E">Eric Herbst</a>, <a href="/search/astro-ph?searchtype=author&query=Davis%2C+S+W">Shane W. Davis</a>, <a href="/search/astro-ph?searchtype=author&query=Garrod%2C+R+T">Robin T. Garrod</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="2207.04269v1-abstract-short" style="display: inline;"> Chemical models and experiments indicate that interstellar dust grains and their ice mantles play an important role in the production of complex organic molecules (COMs). To date, the most complex solid-phase molecule detected with certainty in the ISM is methanol, but the James Webb Space Telescope (JWST) may be able to identify still larger organic species. In this study, we use a coupled chemo-… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2207.04269v1-abstract-full').style.display = 'inline'; document.getElementById('2207.04269v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2207.04269v1-abstract-full" style="display: none;"> Chemical models and experiments indicate that interstellar dust grains and their ice mantles play an important role in the production of complex organic molecules (COMs). To date, the most complex solid-phase molecule detected with certainty in the ISM is methanol, but the James Webb Space Telescope (JWST) may be able to identify still larger organic species. In this study, we use a coupled chemo-dynamical model to predict new candidate species for JWST detection toward the young star-forming core Cha-MMS1, combining the gas-grain chemical kinetic code MAGICKAL with a 1-D radiative hydrodynamics simulation using Athena++. With this model, the relative abundances of the main ice constituents with respect to water toward the core center match well with typical observational values, providing a firm basis to explore the ice chemistry. Six oxygen-bearing COMs (ethanol, dimethyl ether, acetaldehyde, methyl formate, methoxy methanol, and acetic acid), as well as formic acid, show abundances as high as, or exceeding, 0.01% with respect to water ice. Based on the modeled ice composition, the infrared spectrum is synthesized to diagnose the detectability of the new ice species. The contribution of COMs to IR absorption bands is minor compared to the main ice constituents, and the identification of COM ice toward the core center of Cha-MMS1 with the JWST NIRCAM/Wide Field Slitless Spectroscopy (2.4-5.0 micron) may be unlikely. However, MIRI observations (5-28 micron) toward COM-rich environments where solid-phase COM abundances exceed 1% with respect to the water ice column density might reveal the distinctive ice features of COMs. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2207.04269v1-abstract-full').style.display = 'none'; document.getElementById('2207.04269v1-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 July, 2022; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> July 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 to ApJ (28 Pages, 11 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/2205.05082">arXiv:2205.05082</a> <span> [<a href="https://arxiv.org/pdf/2205.05082">pdf</a>, <a href="https://arxiv.org/format/2205.05082">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Earth and Planetary Astrophysics">astro-ph.EP</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="Instrumentation and Methods for Astrophysics">astro-ph.IM</span> <span class="tag is-small is-grey 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="Optics">physics.optics</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/ac7724">10.3847/1538-4357/ac7724 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> A Novel Solution for Resonant Scattering Using Self-Consistent Boundary Conditions </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=McClellan%2C+B+C">B. Connor McClellan</a>, <a href="/search/astro-ph?searchtype=author&query=Davis%2C+S">Shane Davis</a>, <a href="/search/astro-ph?searchtype=author&query=Arras%2C+P">Phil Arras</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="2205.05082v1-abstract-short" style="display: inline;"> We present two novel additions to the semi-analytic solution of Lyman $伪$ (Ly$伪$) radiative transfer in spherical geometry: (1) implementation of the correct boundary condition for a steady source, and (2) solution of the time-dependent problem for an impulsive source. For the steady-state problem, the solution can be represented as a sum of two terms: a previously-known analytic solution of the e… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2205.05082v1-abstract-full').style.display = 'inline'; document.getElementById('2205.05082v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2205.05082v1-abstract-full" style="display: none;"> We present two novel additions to the semi-analytic solution of Lyman $伪$ (Ly$伪$) radiative transfer in spherical geometry: (1) implementation of the correct boundary condition for a steady source, and (2) solution of the time-dependent problem for an impulsive source. For the steady-state problem, the solution can be represented as a sum of two terms: a previously-known analytic solution of the equation with mean intensity $J=0$ at the surface, and a novel, semi-analytic solution which enforces the correct boundary condition of zero-ingoing intensity at the surface. This solution is compared to that of the Monte Carlo method, which is valid at arbitrary optical depth. It is shown that the size of the correction is of order unity when the spectral peaks approach the Doppler core and decreases slowly with line center optical depth, specifically as $(a 蟿_0)^{-1/3}$, which may explain discrepancies seen in previous studies. For the impulsive problem, the time, spatial, and frequency dependence of the solution are expressed using an eigenfunction expansion in order to characterize the escape time distribution and emergent spectra of photons. It is shown that the lowest-order eigenfrequency agrees well with the decay rate found in the Monte Carlo escape time distribution at sufficiently large line-center optical depths. The characterization of the escape-time distribution highlights the potential for a Monte Carlo acceleration method, which would sample photon escape properties from distributions rather than calculating every photon scattering, thereby reducing computational demand. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2205.05082v1-abstract-full').style.display = 'none'; document.getElementById('2205.05082v1-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 May, 2022; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> May 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">23 pages, 10 figures, 2 appendices, resubmitted to ApJ after review</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2204.08543">arXiv:2204.08543</a> <span> [<a href="https://arxiv.org/pdf/2204.08543">pdf</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/ac69dc">10.3847/1538-4357/ac69dc <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> CR Driven Multi-phase Gas Formed via Thermal Instability </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Huang%2C+X">Xiaoshan Huang</a>, <a href="/search/astro-ph?searchtype=author&query=Jiang%2C+Y">Yan-fei Jiang</a>, <a href="/search/astro-ph?searchtype=author&query=Davis%2C+S+W">Shane W. Davis</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="2204.08543v2-abstract-short" style="display: inline;"> Cosmic rays (CRs) are an important energy source in the circum-galactic medium (CGM) that impact the multi-phase gas structure and dynamics. We perform two-dimensional CR-magnetohydrodynamic simulations to investigate the role of CRs in accelerating multi-phase gas formed via thermal instability. We compare outflows driven by CRs to those driven by a hot wind with equivalent momentum. We find that… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2204.08543v2-abstract-full').style.display = 'inline'; document.getElementById('2204.08543v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2204.08543v2-abstract-full" style="display: none;"> Cosmic rays (CRs) are an important energy source in the circum-galactic medium (CGM) that impact the multi-phase gas structure and dynamics. We perform two-dimensional CR-magnetohydrodynamic simulations to investigate the role of CRs in accelerating multi-phase gas formed via thermal instability. We compare outflows driven by CRs to those driven by a hot wind with equivalent momentum. We find that CRs driven outflow produces lower density contrast between cold and hot gas due to non-thermal pressure support, and yields a more filamentary cloud morphology. While entrainment in a hot wind can lead to cold gas increasing due to efficient cooling, CRs tend to suppress cold gas growth. The mechanism of this suppression depends on magnetic field strength, with CRs either reducing cooling or shredding the clouds by differential acceleration. Despite the suppression of cold gas growth, CRs are able to launch the cold clouds to observed velocities without rapid destruction. The dynamical interaction between CRs ad multi-phase gas is also sensitive to the magnetic field strength. In relatively strong fields, the CRs are more important for direct momentum input to cold gas. In relatively weak fields, the CRs impact gas primarily by heating, which modifies gas pressure. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2204.08543v2-abstract-full').style.display = 'none'; document.getElementById('2204.08543v2-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 June, 2022; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 18 April, 2022; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> April 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">22 pages, 18 figures</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> 2022 ApJ 931 140 </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2110.12083">arXiv:2110.12083</a> <span> [<a href="https://arxiv.org/pdf/2110.12083">pdf</a>, <a href="https://arxiv.org/format/2110.12083">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/ac4030">10.3847/1538-4357/ac4030 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Carnegie Supernova Project-II: Near-infrared Spectroscopy of Stripped-Envelope Core-Collapse Supernovae </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Shahbandeh%2C+M">M. Shahbandeh</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=Ashall%2C+C">C. Ashall</a>, <a href="/search/astro-ph?searchtype=author&query=Teffs%2C+J">J. Teffs</a>, <a href="/search/astro-ph?searchtype=author&query=Hoeflich%2C+P">P. Hoeflich</a>, <a href="/search/astro-ph?searchtype=author&query=Morrell%2C+N">N. Morrell</a>, <a href="/search/astro-ph?searchtype=author&query=Phillips%2C+M+M">M. M. Phillips</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=Baron%2C+E">E. Baron</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=Contreras%2C+C">C. Contreras</a>, <a href="/search/astro-ph?searchtype=author&query=Davis%2C+S">S. Davis</a>, <a href="/search/astro-ph?searchtype=author&query=Diamond%2C+T+R">T. R. Diamond</a>, <a href="/search/astro-ph?searchtype=author&query=Folatelli%2C+G">G. Folatelli</a>, <a href="/search/astro-ph?searchtype=author&query=Galbany%2C+L">L. Galbany</a>, <a href="/search/astro-ph?searchtype=author&query=Gall%2C+C">C. Gall</a>, <a href="/search/astro-ph?searchtype=author&query=Hachinger%2C+S">S. Hachinger</a>, <a href="/search/astro-ph?searchtype=author&query=Holmbo%2C+S">S. Holmbo</a>, <a href="/search/astro-ph?searchtype=author&query=Karamehmetoglu%2C+E">E. Karamehmetoglu</a>, <a href="/search/astro-ph?searchtype=author&query=Kasliwal%2C+M+M">M. M. Kasliwal</a>, <a href="/search/astro-ph?searchtype=author&query=Kirshner%2C+R+P">R. P. Kirshner</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=Marion%2C+G+H">G. H. Marion</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="2110.12083v1-abstract-short" style="display: inline;"> We present 75 near-infrared (NIR; 0.8$-$2.5 $渭$m) spectra of 34 stripped-envelope core-collapse supernovae (SESNe) obtained by the Carnegie Supernova Project-II (CSP-II), encompassing optical spectroscopic Types IIb, Ib, Ic, and Ic-BL. The spectra range in phase from pre-maximum to 80 days past maximum. This unique data set constitutes the largest NIR spectroscopic sample of SESNe to date. NIR spe… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2110.12083v1-abstract-full').style.display = 'inline'; document.getElementById('2110.12083v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2110.12083v1-abstract-full" style="display: none;"> We present 75 near-infrared (NIR; 0.8$-$2.5 $渭$m) spectra of 34 stripped-envelope core-collapse supernovae (SESNe) obtained by the Carnegie Supernova Project-II (CSP-II), encompassing optical spectroscopic Types IIb, Ib, Ic, and Ic-BL. The spectra range in phase from pre-maximum to 80 days past maximum. This unique data set constitutes the largest NIR spectroscopic sample of SESNe to date. NIR spectroscopy provides observables with additional information that is not available in the optical. Specifically, the NIR contains the resonance lines of He I and allows a more detailed look at whether Type Ic supernovae are completely stripped of their outer He layer. The NIR spectra of SESNe have broad similarities, but closer examination through statistical means reveals a strong dichotomy between NIR "He-rich" and "He-poor" SNe. These NIR subgroups correspond almost perfectly to the optical IIb/Ib and Ic/Ic-BL types, respectively. The largest difference between the two groups is observed in the 2 $渭$m region, near the He I $位$2.0581 $渭$m line. The division between the two groups is not an arbitrary one along a continuous sequence. Early spectra of He-rich SESNe show much stronger He I $位$2.0581 $渭$m absorption compared to the He-poor group, but with a wide range of profile shapes. The same line also provides evidence for trace amounts of He in half of our SNe in the He-poor group. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2110.12083v1-abstract-full').style.display = 'none'; document.getElementById('2110.12083v1-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 October, 2021; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> October 2021. </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2109.03359">arXiv:2109.03359</a> <span> [<a href="https://arxiv.org/pdf/2109.03359">pdf</a>, <a href="https://arxiv.org/format/2109.03359">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 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/ac250d">10.3847/1538-4357/ac250d <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Measuring an off-Center Detonation through Infrared Line Profiles: The peculiar Type Ia Supernova SN~2020qxp/ASASSN-20jq </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Hoeflich%2C+P">P. Hoeflich</a>, <a href="/search/astro-ph?searchtype=author&query=Ashall%2C+C">C. Ashall</a>, <a href="/search/astro-ph?searchtype=author&query=Bose%2C+S">S. Bose</a>, <a href="/search/astro-ph?searchtype=author&query=Baron%2C+E">E. Baron</a>, <a href="/search/astro-ph?searchtype=author&query=Stritzinger%2C+M+D">M. D. Stritzinger</a>, <a href="/search/astro-ph?searchtype=author&query=Davis%2C+S">S. Davis</a>, <a href="/search/astro-ph?searchtype=author&query=Shahbandeh%2C+M">M. Shahbandeh</a>, <a href="/search/astro-ph?searchtype=author&query=Anand%2C+G+S">G. S. Anand</a>, <a href="/search/astro-ph?searchtype=author&query=Baade%2C+D">D. Baade</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=Collins%2C+D+C">D. C. Collins</a>, <a href="/search/astro-ph?searchtype=author&query=Diamond%2C+T+R">T. R. Diamond</a>, <a href="/search/astro-ph?searchtype=author&query=Fisher%2C+A">A. Fisher</a>, <a href="/search/astro-ph?searchtype=author&query=Galbany%2C+L">L. Galbany</a>, <a href="/search/astro-ph?searchtype=author&query=Hristov%2C+B+A">B. A. Hristov</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=Phillips%2C+M+M">M. M. Phillips</a>, <a href="/search/astro-ph?searchtype=author&query=Shappee%2C+B">B. Shappee</a>, <a href="/search/astro-ph?searchtype=author&query=Suntzeff%2C+N+B">N. B. Suntzeff</a>, <a href="/search/astro-ph?searchtype=author&query=Tucker%2C+M">M. Tucker</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="2109.03359v1-abstract-short" style="display: inline;"> We present and analyze a near infrared(NIR) spectrum of the under-luminous Type Ia supernova SN~2020qxp/ASASSN-20jq obtained with NIRES at the Keck Observatory 191 days after B-band maximum. The spectrum is dominated by a number of broad emission features including the [FeII] at 1.644mu which is highly asymmetric with a tilted top and a peak red-shifted by ~2,000km/s. In comparison with 2-D non-LT… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2109.03359v1-abstract-full').style.display = 'inline'; document.getElementById('2109.03359v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2109.03359v1-abstract-full" style="display: none;"> We present and analyze a near infrared(NIR) spectrum of the under-luminous Type Ia supernova SN~2020qxp/ASASSN-20jq obtained with NIRES at the Keck Observatory 191 days after B-band maximum. The spectrum is dominated by a number of broad emission features including the [FeII] at 1.644mu which is highly asymmetric with a tilted top and a peak red-shifted by ~2,000km/s. In comparison with 2-D non-LTE synthetic spectra computed from 3-D simulations of off-center delayed-detonation Chandrasekhar-mass white-dwarf(WD) models, we find good agreement between the observed lines and the synthetic profiles, and are able to unravel the structure of the progenitor's envelope. We find that the size and tilt of the [Fe II] 1.644mu-profile (in velocity space) is an effective way to determine the location of an off-center delayed-detonation transition (DDT) and the viewing angle, and it requires a WD with a high central density of ~4E9$g/cm^3$. We also tentatively identify a stable Ni feature around 1.9mu characterized by a `pot-belly' profile that is slightly offset with respect to the kinematic center. In the case of SN~2020qxp/ASASSN-20jq, we estimate that the location of the DDT is ~0.3M(WD) off-center, which gives rise to an asymmetric distribution of the underlying ejecta. We also demonstrate that low-luminosity and high-density WD SNIa progenitors exhibit a very strong overlap of Ca and 56Ni in physical space. This results in the formation of a prevalent [Ca II] 0.73mu emission feature, which is sensitive to asymmetry effects. Our findings are discussed within the context of alternative scenarios, including off-center C/O detonations in He-triggered sub-M(Ch)-WDs and the direct collision of two WDs. Snapshot programs with Gemini/Keck/VLT/ELT class instruments and our spectropolarimetry program are complementary to mid-IR spectra by JWST. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2109.03359v1-abstract-full').style.display = 'none'; document.getElementById('2109.03359v1-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 September, 2021; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> September 2021. </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">29 pages, 6 figures, 6 Tables, to appear in The Astrophysical Journal (submitted: 7/26/21, revised: 9/4/21, accepted: 9/7/21)</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2108.07278">arXiv:2108.07278</a> <span> [<a href="https://arxiv.org/pdf/2108.07278">pdf</a>, <a href="https://arxiv.org/format/2108.07278">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> </div> </div> <p class="title is-5 mathjax"> SN 2021csp -- the explosion of a stripped envelope star within a H and He-poor circumstellar medium </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Fraser%2C+M">Morgan Fraser</a>, <a href="/search/astro-ph?searchtype=author&query=Stritzinger%2C+M+D">Maximilian D. Stritzinger</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=Pastorello%2C+A">Andrea Pastorello</a>, <a href="/search/astro-ph?searchtype=author&query=Cai%2C+Y">Yongzhi Cai</a>, <a href="/search/astro-ph?searchtype=author&query=Piro%2C+A+L">Anthony L. Piro</a>, <a href="/search/astro-ph?searchtype=author&query=Ashall%2C+C">Chris Ashall</a>, <a href="/search/astro-ph?searchtype=author&query=Brown%2C+P">Peter Brown</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=Elias-Rosa%2C+N">Nancy Elias-Rosa</a>, <a href="/search/astro-ph?searchtype=author&query=Kotak%2C+R">Rubina Kotak</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=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=Jha%2C+S+W">Saurabh W. Jha</a>, <a href="/search/astro-ph?searchtype=author&query=Reguitti%2C+A">Andrea Reguitti</a>, <a href="/search/astro-ph?searchtype=author&query=Zhang%2C+J">Ju-jia Zhang</a>, <a href="/search/astro-ph?searchtype=author&query=Moran%2C+S">Shane Moran</a>, <a href="/search/astro-ph?searchtype=author&query=Morrell%2C+N">Nidia Morrell</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=Tomasella%2C+L">Lina Tomasella</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=Barna%2C+T">Tyler Barna</a>, <a href="/search/astro-ph?searchtype=author&query=Ochner%2C+P">Paolo Ochner</a>, <a href="/search/astro-ph?searchtype=author&query=Phillips%2C+M+M">M. M. Phillips</a> , et al. (26 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="2108.07278v1-abstract-short" style="display: inline;"> We present observations of SN 2021csp, a unique supernova (SN) which displays evidence for interaction with H- and He- poor circumstellar material (CSM) at early times. Using high-cadence spectroscopy taken over the first week after explosion, we show that the spectra of SN 2021csp are dominated by C III lines with a velocity of 1800 km s$^{-1}$. We associate this emission with CSM lost by the pro… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2108.07278v1-abstract-full').style.display = 'inline'; document.getElementById('2108.07278v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2108.07278v1-abstract-full" style="display: none;"> We present observations of SN 2021csp, a unique supernova (SN) which displays evidence for interaction with H- and He- poor circumstellar material (CSM) at early times. Using high-cadence spectroscopy taken over the first week after explosion, we show that the spectra of SN 2021csp are dominated by C III lines with a velocity of 1800 km s$^{-1}$. We associate this emission with CSM lost by the progenitor prior to explosion. Subsequently, the SN displays narrow He lines before metamorphosing into a broad-lined Type Ic SN. We model the bolometric light curve of SN 2021csp, and show that it is consistent with the energetic ($4\times10^{51}$ erg) explosion of a stripped star, producing 0.4 M$_\odot$ of 56Ni within a $\sim$1 M$_\odot$ shell of CSM extending out to 400 R$_\odot$. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2108.07278v1-abstract-full').style.display = 'none'; document.getElementById('2108.07278v1-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> 16 August, 2021; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> August 2021. </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 pg, submitted</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2107.08150">arXiv:2107.08150</a> <span> [<a href="https://arxiv.org/pdf/2107.08150">pdf</a>, <a href="https://arxiv.org/format/2107.08150">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/ac1606">10.3847/1538-4357/ac1606 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> ASASSN-15hy: an under-luminous, red 03fg-like type Ia supernova </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Lu%2C+J">J. Lu</a>, <a href="/search/astro-ph?searchtype=author&query=Ashall%2C+C">C. Ashall</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=Hoeflich%2C+P">P. Hoeflich</a>, <a href="/search/astro-ph?searchtype=author&query=Galbany%2C+L">L. Galbany</a>, <a href="/search/astro-ph?searchtype=author&query=Baron%2C+E">E. Baron</a>, <a href="/search/astro-ph?searchtype=author&query=Phillips%2C+M+M">M. M. Phillips</a>, <a href="/search/astro-ph?searchtype=author&query=Contreras%2C+C">C. Contreras</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=Suntzeff%2C+N+B">N. B. Suntzeff</a>, <a href="/search/astro-ph?searchtype=author&query=Stritzinger%2C+M+D">M. D. Stritzinger</a>, <a href="/search/astro-ph?searchtype=author&query=Anais%2C+J">J. Anais</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=Brown%2C+P+J">P. J. Brown</a>, <a href="/search/astro-ph?searchtype=author&query=Busta%2C+L">L. Busta</a>, <a href="/search/astro-ph?searchtype=author&query=Castell%C3%B3n%2C+S">S. Castell贸n</a>, <a href="/search/astro-ph?searchtype=author&query=Davis%2C+S">S. Davis</a>, <a href="/search/astro-ph?searchtype=author&query=Diamond%2C+T">T. Diamond</a>, <a href="/search/astro-ph?searchtype=author&query=Falco%2C+E">E. Falco</a>, <a href="/search/astro-ph?searchtype=author&query=Gonzalez%2C+C">C. Gonzalez</a>, <a href="/search/astro-ph?searchtype=author&query=Hamuy%2C+M">M. Hamuy</a>, <a href="/search/astro-ph?searchtype=author&query=Holmbo%2C+S">S. Holmbo</a>, <a href="/search/astro-ph?searchtype=author&query=Holoien%2C+T+W+-">T. W. -S. Holoien</a>, <a href="/search/astro-ph?searchtype=author&query=Krisciunas%2C+K">K. Krisciunas</a>, <a href="/search/astro-ph?searchtype=author&query=Kirshner%2C+R+P">R. P. Kirshner</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="2107.08150v2-abstract-short" style="display: inline;"> We present photometric and spectroscopic observations of the 03fg-like type Ia supernova (SN Ia) ASASSN-15hy from the ultraviolet (UV) to the near-infrared (NIR). ASASSN-15hy shares many of the hallmark characteristics of 03fg-like SNe Ia, previously referred to as "super-Chandrasekhar" SNe Ia. It is bright in the UV and NIR, lacks a clear i-band secondary maximum, shows a strong and persistent C… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2107.08150v2-abstract-full').style.display = 'inline'; document.getElementById('2107.08150v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2107.08150v2-abstract-full" style="display: none;"> We present photometric and spectroscopic observations of the 03fg-like type Ia supernova (SN Ia) ASASSN-15hy from the ultraviolet (UV) to the near-infrared (NIR). ASASSN-15hy shares many of the hallmark characteristics of 03fg-like SNe Ia, previously referred to as "super-Chandrasekhar" SNe Ia. It is bright in the UV and NIR, lacks a clear i-band secondary maximum, shows a strong and persistent C II feature, and has a low Si II $位$6355 velocity. However, some of its properties are also extreme among the subgroup. ASASSN-15hy is under-luminous (M$_{B,peak}=-19.14^{+0.11}_{-0.16}$ mag), red ($(B-V)_{Bmax}=0.18^{+0.01}_{-0.03}$ mag), yet slowly declining ($螖{m_{15}}(B)=0.72 \pm 0.04$ mag). It has the most delayed onset of the i-band maximum of any 03fg-like SN. ASASSN-15hy lacks the prominent H-band break emission feature that is typically present during the first month past maximum in normal SNe Ia. Such events may be a potential problem for high-redshift SN Ia cosmology. ASASSN-15hy may be explained in the context of an explosion of a degenerate core inside a non-degenerate envelope. The explosion impacting the non-degenerate envelope with a large mass provides additional luminosity and low ejecta velocities. An initial deflagration burning phase is critical in reproducing the low $^{56}$Ni mass and luminosity, while the large core mass is essential in providing the large diffusion time scales required to produce the broad light curves. The model consists of a rapidly rotating 1.47 $M_{\odot}$ degenerate core and a 0.8 $M_{\odot}$ non-degenerate envelope. This "deflagration core-degenerate" scenario may result from the merger between a white dwarf and the degenerate core of an asymptotic giant branch star. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2107.08150v2-abstract-full').style.display = 'none'; document.getElementById('2107.08150v2-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 September, 2021; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 16 July, 2021; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> July 2021. </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">41 pages, 21 figures, accepted 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/2106.12140">arXiv:2106.12140</a> <span> [<a href="https://arxiv.org/pdf/2106.12140">pdf</a>, <a href="https://arxiv.org/format/2106.12140">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 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/ac19ac">10.3847/1538-4357/ac19ac <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Carnegie Supernova Project: The First Homogeneous Sample of "Super-Chandrasekhar Mass"/2003fg-like Type Ia Supernova </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=Lu%2C+J">J. Lu</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=Hoeflich%2C+P">P. Hoeflich</a>, <a href="/search/astro-ph?searchtype=author&query=Phillips%2C+M+M">M. M. Phillips</a>, <a href="/search/astro-ph?searchtype=author&query=Galbany%2C+L">L. Galbany</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=Contreras%2C+C">C. Contreras</a>, <a href="/search/astro-ph?searchtype=author&query=Krisciunas%2C+K">K. Krisciunas</a>, <a href="/search/astro-ph?searchtype=author&query=Morrell%2C+N">N. Morrell</a>, <a href="/search/astro-ph?searchtype=author&query=Stritzinger%2C+M+D">M. D. Stritzinger</a>, <a href="/search/astro-ph?searchtype=author&query=Suntzeff%2C+N+B">N. B. Suntzeff</a>, <a href="/search/astro-ph?searchtype=author&query=Taddia%2C+F">F. Taddia</a>, <a href="/search/astro-ph?searchtype=author&query=Anais%2C+J">J. Anais</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">P. J. Brown</a>, <a href="/search/astro-ph?searchtype=author&query=Busta%2C+L">L. Busta</a>, <a href="/search/astro-ph?searchtype=author&query=Campillay%2C+A">A. Campillay</a>, <a href="/search/astro-ph?searchtype=author&query=Castell%C3%B3n%2C+S">S. Castell贸n</a>, <a href="/search/astro-ph?searchtype=author&query=Corco%2C+C">C. Corco</a>, <a href="/search/astro-ph?searchtype=author&query=Davis%2C+S">S. Davis</a>, <a href="/search/astro-ph?searchtype=author&query=Folatelli%2C+G">G. Folatelli</a>, <a href="/search/astro-ph?searchtype=author&query=Forster%2C+F">F. Forster</a>, <a href="/search/astro-ph?searchtype=author&query=Freedman%2C+W+L">W. L. Freedman</a>, <a href="/search/astro-ph?searchtype=author&query=Gonzal%C3%A9z%2C+C">C. Gonzal茅z</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="2106.12140v2-abstract-short" style="display: inline;"> We present a multi-wavelength photometric and spectroscopic analysis of thirteen "Super-Chandrasekhar Mass"/2003fg-like type Ia Supernova (SNe~Ia). Nine of these objects were observed by the Carnegie Supernova Project. 2003fg-like have slowly declining light curves ($螖m_{15}$(B) $<$1.3 mag), and peak absolute $B$-band magnitudes between $-19<M_{B}<-21$~mag. Many 2003fg-like are located in the same… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2106.12140v2-abstract-full').style.display = 'inline'; document.getElementById('2106.12140v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2106.12140v2-abstract-full" style="display: none;"> We present a multi-wavelength photometric and spectroscopic analysis of thirteen "Super-Chandrasekhar Mass"/2003fg-like type Ia Supernova (SNe~Ia). Nine of these objects were observed by the Carnegie Supernova Project. 2003fg-like have slowly declining light curves ($螖m_{15}$(B) $<$1.3 mag), and peak absolute $B$-band magnitudes between $-19<M_{B}<-21$~mag. Many 2003fg-like are located in the same part of the luminosity width relation as normal SNe~Ia. In the optical $B$ and $V$ bands, 2003fg-like look like normal SNe~Ia, but at redder wavelengths they diverge. Unlike other luminous SNe~Ia, 2003fg-like generally have only one $i$-band maximum which peaks after the epoch of $B$-band maximum, while their NIR light curve rise times can be $\gtrsim$40 days longer than those of normal SNe~Ia. They are also at least one magnitude brighter in the NIR bands than normal SNe~Ia, peaking above $M_H < -19$~mag, and generally have negative Hubble residuals, which may be the cause of some systematics in dark energy experiments. Spectroscopically, 2003fg-like exhibit peculiarities such as unburnt carbon well past maximum light, a large spread (8000--12000~km/s) in SiII $位$6355 velocities at maximum light with no rapid early velocity decline, and no clear $H$-band break at +10~d, e. We find that SNe with a larger pseudo equivalent width of CII at maximum light have lower SiII $位$6355 velocities and slower declining light curves. There are also multiple factors that contribute to the peak luminosity of 2003fg-like. The explosion of a C-O degenerate core inside a carbon-rich envelope is consistent with these observations. Such a configuration may come from the core degenerate scenario. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2106.12140v2-abstract-full').style.display = 'none'; document.getElementById('2106.12140v2-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> 31 August, 2021; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 22 June, 2021; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> June 2021. </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/2105.11506">arXiv:2105.11506</a> <span> [<a href="https://arxiv.org/pdf/2105.11506">pdf</a>, <a href="https://arxiv.org/format/2105.11506">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/10.1093/mnras/stac059">10.1093/mnras/stac059 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> The Launching of Cosmic Ray Driven Outflows </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Huang%2C+X">Xiaoshan Huang</a>, <a href="/search/astro-ph?searchtype=author&query=Davis%2C+S+W">Shane W. Davis</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="2105.11506v2-abstract-short" style="display: inline;"> Cosmic rays (CRs) are thought to be an important feedback mechanism in star-forming galaxies. They can provide an important source of pressure support and possibly drive outflows. We perform multidimensional CR-magnetohydrodynamic simulations including transport by streaming and diffusion to investigate wind launching from an initially hydrostatic atmosphere by CRs. We estimate a characteristic Ed… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2105.11506v2-abstract-full').style.display = 'inline'; document.getElementById('2105.11506v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2105.11506v2-abstract-full" style="display: none;"> Cosmic rays (CRs) are thought to be an important feedback mechanism in star-forming galaxies. They can provide an important source of pressure support and possibly drive outflows. We perform multidimensional CR-magnetohydrodynamic simulations including transport by streaming and diffusion to investigate wind launching from an initially hydrostatic atmosphere by CRs. We estimate a characteristic Eddington limit on the CR flux for which the CR force exceeds gravity and compare it to simulated systems. Scaling our results to conditions in star-forming galaxies, we find that CRs are likely to contribute to driving outflows for a broad range of star formation environments. We quantify the momentum and energy transfer between CRs and gas, along with the associated mass outflow rates under different assumptions about the relative importance of streaming and diffusion for transport. In simulations with streaming, we observe the growth and saturation of the CR acoustic instability, but the CRs and gas remain well coupled, with CR momentum transferred efficiently to the gas even when this instability is present. Higher CR fluxes transferr more energy to the gas and drive stronger outflows. When streaming is present, most of the transferred energy takes the form of Alfv茅n wave heating of the gas, raising its pressure and internal energy, with a lower fractional contribution to the kinetic energy of the outflow. We also consider runs with radiative cooling, which modifies gas temperature and pressure profiles but does not seem to have a large impact on the mass outflow for super-Eddington CR fluxes. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2105.11506v2-abstract-full').style.display = 'none'; document.getElementById('2105.11506v2-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 February, 2022; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 24 May, 2021; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> May 2021. </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, 19 figures, 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/2101.11655">arXiv:2101.11655</a> <span> [<a href="https://arxiv.org/pdf/2101.11655">pdf</a>, <a href="https://arxiv.org/format/2101.11655">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/abf2b7">10.3847/1538-4357/abf2b7 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> The black hole spin in GRS 1915+105, revisited </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Mills%2C+B+S">Brianna S. Mills</a>, <a href="/search/astro-ph?searchtype=author&query=Davis%2C+S+W">Shane W. Davis</a>, <a href="/search/astro-ph?searchtype=author&query=Middleton%2C+M+J">Matthew J. Middleton</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="2101.11655v2-abstract-short" style="display: inline;"> We estimate the black hole spin parameter in GRS 1915+105 using the continuum-fitting method with revised mass and inclination constraints based on the very long baseline interferometric parallax measurement of the distance to this source. We fit Rossi X-ray Timing Explorer observations selected to be accretion disk-dominated spectral states as described in McClintock et al. (2006) and Middleton e… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2101.11655v2-abstract-full').style.display = 'inline'; document.getElementById('2101.11655v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2101.11655v2-abstract-full" style="display: none;"> We estimate the black hole spin parameter in GRS 1915+105 using the continuum-fitting method with revised mass and inclination constraints based on the very long baseline interferometric parallax measurement of the distance to this source. We fit Rossi X-ray Timing Explorer observations selected to be accretion disk-dominated spectral states as described in McClintock et al. (2006) and Middleton et al. (2006), which previously gave discrepant spin estimates with this method. We find that, using the new system parameters, the spin in both datasets increased, providing a best-fit spin of $a_*=0.86$ for the Middleton et al. data and a poor fit for the McClintock et al. dataset, which becomes pegged at the BHSPEC model limit of $a_*=0.99$. We explore the impact of the uncertainties in the system parameters, showing that the best-fit spin ranges from $a_*= 0.4$ to 0.99 for the Middleton et al. dataset and allows reasonable fits to the McClintock et al. dataset with near maximal spin for system distances greater than $\sim 10$ kpc. We discuss the uncertainties and implications of these estimates. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2101.11655v2-abstract-full').style.display = 'none'; document.getElementById('2101.11655v2-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 July, 2024; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 27 January, 2021; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> January 2021. </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, 5 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/2101.08839">arXiv:2101.08839</a> <span> [<a href="https://arxiv.org/pdf/2101.08839">pdf</a>, <a href="https://arxiv.org/format/2101.08839">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/10.1146/annurev-astro-081817-051905">10.1146/annurev-astro-081817-051905 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Magnetohydrodynamic Simulations of Active Galactic Nucleus Disks and Jets </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Davis%2C+S+W">Shane W. Davis</a>, <a href="/search/astro-ph?searchtype=author&query=Tchekhovskoy%2C+A">Alexander Tchekhovskoy</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="2101.08839v1-abstract-short" style="display: inline;"> There is a broad consensus that accretion onto supermassive black holes and consequent jet formation power the observed emission from active galactic nuclei (AGNs). However, there has been less agreement about how jets form in accretion flows, their possible relationship to black hole spin, and how they interact with the surrounding medium. There have also been theoretical concerns about instabili… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2101.08839v1-abstract-full').style.display = 'inline'; document.getElementById('2101.08839v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2101.08839v1-abstract-full" style="display: none;"> There is a broad consensus that accretion onto supermassive black holes and consequent jet formation power the observed emission from active galactic nuclei (AGNs). However, there has been less agreement about how jets form in accretion flows, their possible relationship to black hole spin, and how they interact with the surrounding medium. There have also been theoretical concerns about instabilities in standard accretion disk models and lingering discrepancies with observational constraints. Despite seemingly successful applications to X-ray binaries, the standard accretion disk model faces a growing list of observational constraints that challenge its application to AGNs. Theoretical exploration of these questions has become increasingly reliant on numerical simulations owing to the dynamic nature of these flows and the complex interplay between hydrodynamics, magnetic fields, radiation transfer, and curved spacetime. We conclude the following: The advent of general relativistic magnetohydrodynamics (MHD) simulations has greatly improved our understanding of jet production and its dependence on black hole spin. Simulation results show both disks and jets are sensitive to the magnetic flux threading the accretion flow as well as possible misalignment between the angular momentum of the accretion flow and the black hole spin. Radiation MHD simulations are providing new insights into the stability of luminous accretion flows and highlighting the potential importance of radiation viscosity, UV opacity from atoms, and spiral density waves in AGNs. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2101.08839v1-abstract-full').style.display = 'none'; document.getElementById('2101.08839v1-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> 21 January, 2021; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> January 2021. </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">35 pages, 8 figures, Invited review published in Annual Reviews of Astronomy and Astrophysics</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2101.05424">arXiv:2101.05424</a> <span> [<a href="https://arxiv.org/pdf/2101.05424">pdf</a>, <a href="https://arxiv.org/format/2101.05424">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/abdd36">10.3847/1538-4357/abdd36 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> SN 2013ai: a link between hydrogen-rich and hydrogen-poor core-collapse supernovae </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Davis%2C+S">S. Davis</a>, <a href="/search/astro-ph?searchtype=author&query=Pessi%2C+P+J">P. J. Pessi</a>, <a href="/search/astro-ph?searchtype=author&query=Fraser%2C+M">M. Fraser</a>, <a href="/search/astro-ph?searchtype=author&query=Ertini%2C+K">K. Ertini</a>, <a href="/search/astro-ph?searchtype=author&query=Martinez%2C+L">L. Martinez</a>, <a href="/search/astro-ph?searchtype=author&query=Hoeflich%2C+P">P. Hoeflich</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=Folatelli%2C+G">G. Folatelli</a>, <a href="/search/astro-ph?searchtype=author&query=Ashall%2C+C">C. Ashall</a>, <a href="/search/astro-ph?searchtype=author&query=Phillips%2C+M+M">M. M. Phillips</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=Bersten%2C+M">M. Bersten</a>, <a href="/search/astro-ph?searchtype=author&query=Englert%2C+B">B. Englert</a>, <a href="/search/astro-ph?searchtype=author&query=Fisher%2C+A">A. Fisher</a>, <a href="/search/astro-ph?searchtype=author&query=Benetti%2C+S">S. Benetti</a>, <a href="/search/astro-ph?searchtype=author&query=Bunzel%2C+A">A. Bunzel</a>, <a href="/search/astro-ph?searchtype=author&query=Burns%2C+C">C. Burns</a>, <a href="/search/astro-ph?searchtype=author&query=Chen%2C+T+W">T. W. Chen</a>, <a href="/search/astro-ph?searchtype=author&query=Contreras%2C+C">C. Contreras</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=Falco%2C+E">E. Falco</a>, <a href="/search/astro-ph?searchtype=author&query=Galbany%2C+L">L. Galbany</a>, <a href="/search/astro-ph?searchtype=author&query=Kirshner%2C+R+P">R. P. Kirshner</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> , 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="2101.05424v1-abstract-short" style="display: inline;"> We present a study of optical and near-infrared (NIR) spectra along with the light curves of SN 2013ai. These data range from discovery until 380 days after explosion. SN 2013ai is a fast declining type II supernova (SN II) with an unusually long rise time; $18.9\pm2.7$d in $V$ band and a bright $V$ band peak absolute magnitude of $-18.7\pm0.06$ mag. The spectra are dominated by hydrogen features… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2101.05424v1-abstract-full').style.display = 'inline'; document.getElementById('2101.05424v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2101.05424v1-abstract-full" style="display: none;"> We present a study of optical and near-infrared (NIR) spectra along with the light curves of SN 2013ai. These data range from discovery until 380 days after explosion. SN 2013ai is a fast declining type II supernova (SN II) with an unusually long rise time; $18.9\pm2.7$d in $V$ band and a bright $V$ band peak absolute magnitude of $-18.7\pm0.06$ mag. The spectra are dominated by hydrogen features in the optical and NIR. The spectral features of SN 2013ai are unique in their expansion velocities, which when compared to large samples of SNe II are more than 1,000 kms faster at 50 days past explosion. In addition, the long rise time of the light curve more closely resembles SNe IIb rather than SNe II. If SN 2013ai is coeval with a nearby compact cluster we infer a progenitor ZAMS mass of $\sim$17 M$_\odot$. After performing light curve modeling we find that SN 2013ai could be the result of the explosion of a star with little hydrogen mass, a large amount of synthesized $^{56}$Ni, 0.3-0.4 M$_\odot$, and an explosion energy of $2.5-3.0\times10^{51}$ ergs. The density structure and expansion velocities of SN 2013ai are similar to that of the prototypical SN IIb, SN 1993J. However, SN 2013ai shows no strong helium features in the optical, likely due to the presence of a dense core that prevents the majority of $纬$-rays from escaping to excite helium. Our analysis suggests that SN 2013ai could be a link between SNe II and stripped envelope SNe. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2101.05424v1-abstract-full').style.display = 'none'; document.getElementById('2101.05424v1-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, 2021; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> January 2021. </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">24 pages, 17 figures, accepted 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/2010.09764">arXiv:2010.09764</a> <span> [<a href="https://arxiv.org/pdf/2010.09764">pdf</a>, <a href="https://arxiv.org/format/2010.09764">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/abc417">10.3847/1538-4357/abc417 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Supernova 2018cuf: A Type IIP supernova with a slow fall from plateau </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">S. Valenti</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=Sand%2C+D+J">D. 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=Galbany%2C+L">L. Galbany</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=Eweis%2C+Y">Youssef Eweis</a>, <a href="/search/astro-ph?searchtype=author&query=Kwok%2C+L">Lindsey Kwok</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=Davis%2C+S">Scott Davis</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=Kuncarayakti%2C+H">H. Kuncarayakti</a>, <a href="/search/astro-ph?searchtype=author&query=Maeda%2C+K">Keiichi Maeda</a>, <a href="/search/astro-ph?searchtype=author&query=Rho%2C+J">Jeonghee Rho</a>, <a href="/search/astro-ph?searchtype=author&query=Amaro%2C+R+C">R. C. Amaro</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=Arcavi%2C+I">Iair Arcavi</a>, <a href="/search/astro-ph?searchtype=author&query=Burke%2C+J">Jamison Burke</a>, <a href="/search/astro-ph?searchtype=author&query=Dastidar%2C+R">Raya Dastidar</a>, <a href="/search/astro-ph?searchtype=author&query=Folatelli%22%2C+%22">"Gast贸n Folatelli"</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=Hosseinzadeh%2C+G">Griffin Hosseinzadeh</a>, <a href="/search/astro-ph?searchtype=author&query=Howell%2C+D+A">D. Andrew Howell</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="2010.09764v1-abstract-short" style="display: inline;"> We present multi-band photometry and spectroscopy of SN 2018cuf, a Type IIP ("P" for plateau) supernova (SN) discovered by the Distance Less Than 40 Mpc survey (DLT40) within 24 hours of explosion. SN 2018cuf appears to be a typical Type IIP SN, with an absolute $V$-band magnitude of $-$16.73 $\pm$ 0.32 at maximum and a decline rate of 0.21 $\pm$ 0.05 mag/50d during the plateau phase. The distance… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2010.09764v1-abstract-full').style.display = 'inline'; document.getElementById('2010.09764v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2010.09764v1-abstract-full" style="display: none;"> We present multi-band photometry and spectroscopy of SN 2018cuf, a Type IIP ("P" for plateau) supernova (SN) discovered by the Distance Less Than 40 Mpc survey (DLT40) within 24 hours of explosion. SN 2018cuf appears to be a typical Type IIP SN, with an absolute $V$-band magnitude of $-$16.73 $\pm$ 0.32 at maximum and a decline rate of 0.21 $\pm$ 0.05 mag/50d during the plateau phase. The distance of the object is constrained to be 41.8 $\pm$ 5.7 Mpc by using the expanding photosphere method. We use spectroscopic and photometric observations from the first year after the explosion to constrain the progenitor of SN 2018cuf using both hydrodynamic light curve modelling and late-time spectroscopic modelling. The progenitor of SN 2018cuf was most likely a red supergiant of about 14.5 $\rm M_{\odot}$ that produced 0.04 $\pm$ 0.01 $\rm M_{\odot}$ $\rm ^{56}Ni$ during the explosion. We also found $\sim$ 0.07 $\rm M_{\odot}$ of circumstellar material (CSM) around the progenitor is needed to fit the early light curves, where the CSM may originate from pre-supernova outbursts. During the plateau phase, high velocity features at $\rm \sim 11000\ km~s^{-1}$ are detected both in the optical and near-infrared spectra, supporting the possibility that the ejecta were interacting with some CSM. A very shallow slope during the post-plateau phase is also observed and it is likely due to a low degree of nickel mixing or the relatively high nickel mass in the SN. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2010.09764v1-abstract-full').style.display = 'none'; document.getElementById('2010.09764v1-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 October, 2020; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> October 2020. </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">22 pages, 15 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/2009.11415">arXiv:2009.11415</a> <span> [<a href="https://arxiv.org/pdf/2009.11415">pdf</a>, <a href="https://arxiv.org/ps/2009.11415">ps</a>, <a href="https://arxiv.org/format/2009.11415">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/abba82">10.3847/1538-4357/abba82 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Optical and Near-Infrared Observations of the Nearby Type Ia Supernova 2017cbv </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Wang%2C+L">Lingzhi Wang</a>, <a href="/search/astro-ph?searchtype=author&query=Contreras%2C+C">Carlos Contreras</a>, <a href="/search/astro-ph?searchtype=author&query=Hu%2C+M">Maokai Hu</a>, <a href="/search/astro-ph?searchtype=author&query=Hamuy%2C+M+A">Mario A. Hamuy</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=Sand%2C+D+J">David J. Sand</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=Burns%2C+C+R">Christopher R. Burns</a>, <a href="/search/astro-ph?searchtype=author&query=Chen%2C+J">Juncheng Chen</a>, <a href="/search/astro-ph?searchtype=author&query=Diamond%2C+T+R">Tiara R. Diamond</a>, <a href="/search/astro-ph?searchtype=author&query=Davis%2C+S">Scott Davis</a>, <a href="/search/astro-ph?searchtype=author&query=F%C3%B6rster%2C+F">Francisco F枚rster</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=Gonz%C3%A1lez-Gait%C3%A1n%2C+S">Santiago Gonz谩lez-Gait谩n</a>, <a href="/search/astro-ph?searchtype=author&query=Gromadzki%2C+M">Mariusz Gromadzki</a>, <a href="/search/astro-ph?searchtype=author&query=Hoeflich%2C+P">Peter Hoeflich</a>, <a href="/search/astro-ph?searchtype=author&query=Li%2C+W">Wenxiong Li</a>, <a href="/search/astro-ph?searchtype=author&query=Marion%2C+G+H">G. H. Marion</a>, <a href="/search/astro-ph?searchtype=author&query=Morrell%2C+N">Nidia Morrell</a>, <a href="/search/astro-ph?searchtype=author&query=Pignata%2C+G">Giuliano Pignata</a>, <a href="/search/astro-ph?searchtype=author&query=Prieto%2C+J+L">Jose L. Prieto</a>, <a href="/search/astro-ph?searchtype=author&query=Phillips%2C+M+M">Mark M. Phillips</a>, <a href="/search/astro-ph?searchtype=author&query=Shahbandeh%2C+M">Melissa Shahbandeh</a>, <a href="/search/astro-ph?searchtype=author&query=Suntzeff%2C+N">Nicholas Suntzeff</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="2009.11415v1-abstract-short" style="display: inline;"> Supernova (SN) 2017cbv in NGC 5643 is one of a handful of type Ia supernovae (SNe~Ia) reported to have excess blue emission at early times. This paper presents extensive $BVRIYJHK_s$-band light curves of SN 2017cbv, covering the phase from $-16$ to $+125$ days relative to $B$-band maximum light. SN 2017cbv reached a $B$-band maximum of 11.710$\pm$0.006~mag, with a post-maximum magnitude decline… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2009.11415v1-abstract-full').style.display = 'inline'; document.getElementById('2009.11415v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2009.11415v1-abstract-full" style="display: none;"> Supernova (SN) 2017cbv in NGC 5643 is one of a handful of type Ia supernovae (SNe~Ia) reported to have excess blue emission at early times. This paper presents extensive $BVRIYJHK_s$-band light curves of SN 2017cbv, covering the phase from $-16$ to $+125$ days relative to $B$-band maximum light. SN 2017cbv reached a $B$-band maximum of 11.710$\pm$0.006~mag, with a post-maximum magnitude decline $螖m_{15}(B)$=0.990$\pm$0.013 mag. The supernova suffered no host reddening based on Phillips intrinsic color, Lira-Phillips relation, and the CMAGIC diagram. By employing the CMAGIC distance modulus $渭=30.58\pm0.05$~mag and assuming $H_0$=72~$\rm km \ s^{-1} \ Mpc^{-1}$, we found that 0.73~\msun $^{56}$Ni was synthesized during the explosion of SN 2017cbv, which is consistent with estimates using reddening-free and distance-free methods via the phases of the secondary maximum of the NIR-band light curves. We also present 14 near-infrared spectra from $-18$ to $+49$~days relative to the $B$-band maximum light, providing constraints on the amount of swept-up hydrogen from the companion star in the context of the single degenerate progenitor scenario. No $Pa尾$ emission feature was detected from our post-maximum NIR spectra, placing a hydrogen mass upper limit of 0.1 $M_{\odot}$. The overall optical/NIR photometric and NIR spectral evolution of SN 2017cbv is similar to that of a normal SN~Ia, even though its early evolution is marked by a flux excess no seen in most other well-observed normal SNe~Ia. We also compare the exquisite light curves of SN 2017cbv with some $M_{ch}$ DDT models and sub-$M_{ch}$ double detonation models. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2009.11415v1-abstract-full').style.display = 'none'; document.getElementById('2009.11415v1-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 September, 2020; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> September 2020. </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 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/2008.06515">arXiv:2008.06515</a> <span> [<a href="https://arxiv.org/pdf/2008.06515">pdf</a>, <a href="https://arxiv.org/format/2008.06515">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/abca8a">10.3847/1538-4357/abca8a <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> The early discovery of SN 2017ahn: signatures of persistent interaction in a fast declining Type II supernova </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Tartaglia%2C+L">L. Tartaglia</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=Groh%2C+J+H">J. H. Groh</a>, <a href="/search/astro-ph?searchtype=author&query=Valenti%2C+S">S. Valenti</a>, <a href="/search/astro-ph?searchtype=author&query=Wyatt%2C+S+D">S. D. Wyatt</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=Yang%2C+S">S. Yang</a>, <a href="/search/astro-ph?searchtype=author&query=Burke%2C+J">J. Burke</a>, <a href="/search/astro-ph?searchtype=author&query=Chen%2C+T+-">T. -W. Chen</a>, <a href="/search/astro-ph?searchtype=author&query=Davis%2C+S">S. Davis</a>, <a href="/search/astro-ph?searchtype=author&query=F%C3%B6rster%2C+F">F. F枚rster</a>, <a href="/search/astro-ph?searchtype=author&query=Galbany%2C+L">L. Galbany</a>, <a href="/search/astro-ph?searchtype=author&query=Haislip%2C+J">J. Haislip</a>, <a href="/search/astro-ph?searchtype=author&query=Hiramatsu%2C+D">D. Hiramatsu</a>, <a href="/search/astro-ph?searchtype=author&query=Hosseinzadeh%2C+G">G. Hosseinzadeh</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=Hsiao%2C+E+Y">E. Y. Hsiao</a>, <a href="/search/astro-ph?searchtype=author&query=Jha%2C+S+W">S. W. Jha</a>, <a href="/search/astro-ph?searchtype=author&query=Kouprianov%2C+V">V. Kouprianov</a>, <a href="/search/astro-ph?searchtype=author&query=Kuncarayakti%2C+H">H. Kuncarayakti</a>, <a href="/search/astro-ph?searchtype=author&query=Lyman%2C+J+D">J. D. Lyman</a>, <a href="/search/astro-ph?searchtype=author&query=McCully%2C+C">C. McCully</a>, <a href="/search/astro-ph?searchtype=author&query=Phillips%2C+M+M">M. M. Phillips</a>, <a href="/search/astro-ph?searchtype=author&query=Rau%2C+A">A. Rau</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="2008.06515v2-abstract-short" style="display: inline;"> We present high-cadence, comprehensive data on the nearby ($D\simeq33\,\rm{Mpc}$) Type II SN 2017ahn, discovered within $\sim$1 day of explosion, from the very early phases after explosion to the nebular phase. The observables of SN 2017ahn show a significant evolution over the $\simeq470\,\rm{d}$ of our follow-up campaign, first showing prominent, narrow Balmer lines and other high-ionization fea… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2008.06515v2-abstract-full').style.display = 'inline'; document.getElementById('2008.06515v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2008.06515v2-abstract-full" style="display: none;"> We present high-cadence, comprehensive data on the nearby ($D\simeq33\,\rm{Mpc}$) Type II SN 2017ahn, discovered within $\sim$1 day of explosion, from the very early phases after explosion to the nebular phase. The observables of SN 2017ahn show a significant evolution over the $\simeq470\,\rm{d}$ of our follow-up campaign, first showing prominent, narrow Balmer lines and other high-ionization features purely in emission (i.e. flash spectroscopy features), which progressively fade and lead to a spectroscopic evolution similar to that of more canonical Type II supernovae. Over the same period, the decline of the light curves in all bands is fast, resembling the photometric evolution of linearly declining H-rich core-collapse supernovae. The modeling of the light curves and early flash spectra suggest a complex circumstellar medium surrounding the progenitor star at the time of explosion, with a first dense shell produced during the very late stages of its evolution being swept up by the rapidly expanding ejecta within the first $\sim6\,\rm{d}$ of the supernova evolution, while signatures of interaction are observed also at later phases. Hydrodynamical models support the scenario in which linearly declining Type II supernovae are predicted to arise from massive yellow super/hyper giants depleted of most of their hydrogen layers. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2008.06515v2-abstract-full').style.display = 'none'; document.getElementById('2008.06515v2-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 November, 2020; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 14 August, 2020; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> August 2020. </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 (21+Appendices), 19 figures, 4 tables, accepted for publication on 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/2008.05614">arXiv:2008.05614</a> <span> [<a href="https://arxiv.org/pdf/2008.05614">pdf</a>, <a href="https://arxiv.org/ps/2008.05614">ps</a>, <a href="https://arxiv.org/format/2008.05614">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"> Carnegie Supernova Project II: The slowest rising Type Ia supernova LSQ14fmg and clues to the origin of super-Chandrasekhar/03fg-like events </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Hsiao%2C+E+Y">E. Y. Hsiao</a>, <a href="/search/astro-ph?searchtype=author&query=Hoeflich%2C+P">P. Hoeflich</a>, <a href="/search/astro-ph?searchtype=author&query=Ashall%2C+C">C. Ashall</a>, <a href="/search/astro-ph?searchtype=author&query=Lu%2C+J">J. Lu</a>, <a href="/search/astro-ph?searchtype=author&query=Contreras%2C+C">C. Contreras</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=Phillips%2C+M+M">M. M. Phillips</a>, <a href="/search/astro-ph?searchtype=author&query=Galbany%2C+L">L. Galbany</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=Baltay%2C+C">C. Baltay</a>, <a href="/search/astro-ph?searchtype=author&query=Baron%2C+E">E. Baron</a>, <a href="/search/astro-ph?searchtype=author&query=Castellon%2C+S">S. Castellon</a>, <a href="/search/astro-ph?searchtype=author&query=Davis%2C+S">S. Davis</a>, <a href="/search/astro-ph?searchtype=author&query=Freedman%2C+W+L">Wendy L. Freedman</a>, <a href="/search/astro-ph?searchtype=author&query=Gall%2C+C">C. Gall</a>, <a href="/search/astro-ph?searchtype=author&query=Gonzalez%2C+C">C. Gonzalez</a>, <a href="/search/astro-ph?searchtype=author&query=Graham%2C+M+L">M. L. Graham</a>, <a href="/search/astro-ph?searchtype=author&query=Hamuy%2C+M">M. Hamuy</a>, <a href="/search/astro-ph?searchtype=author&query=Holoien%2C+T+W+-">T. W. -S. Holoien</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=Kuncarayakti%2C+H">H. Kuncarayakti</a>, <a href="/search/astro-ph?searchtype=author&query=Morrell%2C+N">N. Morrell</a>, <a href="/search/astro-ph?searchtype=author&query=Moriya%2C+T+J">T. J. Moriya</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="2008.05614v1-abstract-short" style="display: inline;"> The Type Ia supernova (SN Ia) LSQ14fmg exhibits exaggerated properties which may help to reveal the origin of the "super-Chandrasekhar" (or 03fg-like) group. The optical spectrum is typical of a 03fg-like SN Ia, but the light curves are unlike those of any SNe Ia observed. The light curves of LSQ14fmg rise extremely slowly. At -23 rest-frame days relative to B-band maximum, LSQ14fmg is already bri… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2008.05614v1-abstract-full').style.display = 'inline'; document.getElementById('2008.05614v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2008.05614v1-abstract-full" style="display: none;"> The Type Ia supernova (SN Ia) LSQ14fmg exhibits exaggerated properties which may help to reveal the origin of the "super-Chandrasekhar" (or 03fg-like) group. The optical spectrum is typical of a 03fg-like SN Ia, but the light curves are unlike those of any SNe Ia observed. The light curves of LSQ14fmg rise extremely slowly. At -23 rest-frame days relative to B-band maximum, LSQ14fmg is already brighter than $M_V$=-19 mag before host extinction correction. The observed color curves show a flat evolution from the earliest observation to approximately one week after maximum. The near-infrared light curves peak brighter than -20.5 mag in the J and H bands, far more luminous than any 03fg-like SNe Ia with near-infrared observations. At one month past maximum, the optical light curves decline rapidly. The early, slow rise and flat color evolution are interpreted to result from an additional excess flux from a power source other than the radioactive decay of the synthesized $^{56}Ni$. The excess flux matches the interaction with a typical superwind of an asymptotic giant branch (AGB) star in density structure, mass-loss rate, and duration. The rapid decline starting at around one month past B-band maximum may be an indication of rapid cooling by active carbon monoxide (CO) formation, which requires a low temperature and high density environment. These peculiarities point to an AGB progenitor near the end of its evolution and the core degenerate scenario as the likely explosion mechanism for LSQ14fmg. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2008.05614v1-abstract-full').style.display = 'none'; document.getElementById('2008.05614v1-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 August, 2020; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> August 2020. </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">22 pages, 15 figures, 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/2006.10198">arXiv:2006.10198</a> <span> [<a href="https://arxiv.org/pdf/2006.10198">pdf</a>, <a href="https://arxiv.org/ps/2006.10198">ps</a>, <a href="https://arxiv.org/format/2006.10198">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/10.1051/0004-6361/202038118">10.1051/0004-6361/202038118 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> The Carnegie Supernova Project II. Observations of SN 2014ab possibly revealing a 2010jl-like SN IIn with pre-existing dust </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Moriya%2C+T+J">T. J. Moriya</a>, <a href="/search/astro-ph?searchtype=author&query=Stritzinger%2C+M+D">M. D. Stritzinger</a>, <a href="/search/astro-ph?searchtype=author&query=Taddia%2C+F">F. Taddia</a>, <a href="/search/astro-ph?searchtype=author&query=Morrell%2C+N">N. Morrell</a>, <a href="/search/astro-ph?searchtype=author&query=Suntzeff%2C+N+B">N. B. Suntzeff</a>, <a href="/search/astro-ph?searchtype=author&query=Contreras%2C+C">C. Contreras</a>, <a href="/search/astro-ph?searchtype=author&query=Gall%2C+C">C. Gall</a>, <a href="/search/astro-ph?searchtype=author&query=Hjorth%2C+J">J. Hjorth</a>, <a href="/search/astro-ph?searchtype=author&query=Ashall%2C+C">C. Ashall</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=Busta%2C+L">L. Busta</a>, <a href="/search/astro-ph?searchtype=author&query=Campillay%2C+A">A. Campillay</a>, <a href="/search/astro-ph?searchtype=author&query=Castellon%2C+S">S. Castellon</a>, <a href="/search/astro-ph?searchtype=author&query=Corco%2C+C">C. Corco</a>, <a href="/search/astro-ph?searchtype=author&query=Davis%2C+S">S. Davis</a>, <a href="/search/astro-ph?searchtype=author&query=Galbany%2C+L">L. Galbany</a>, <a href="/search/astro-ph?searchtype=author&query=Gonzalez%2C+C">C. Gonzalez</a>, <a href="/search/astro-ph?searchtype=author&query=Holmbo%2C+S">S. Holmbo</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=Maund%2C+J+R">J. R. Maund</a>, <a href="/search/astro-ph?searchtype=author&query=Phillips%2C+M+M">M. M. Phillips</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="2006.10198v3-abstract-short" style="display: inline;"> We present optical and near-infrared photometry and spectroscopy of the Type IIn supernova (SN) 2014ab, obtained by the Carnegie Supernova Project II (CSP-II) and initiated immediately after its optical discovery. We also present mid-infrared photometry obtained by the Wide-field Infrared Survey Explorer (WISE) satellite extending from 56 days prior to the optical discovery to over 1600 days. The… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2006.10198v3-abstract-full').style.display = 'inline'; document.getElementById('2006.10198v3-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2006.10198v3-abstract-full" style="display: none;"> We present optical and near-infrared photometry and spectroscopy of the Type IIn supernova (SN) 2014ab, obtained by the Carnegie Supernova Project II (CSP-II) and initiated immediately after its optical discovery. We also present mid-infrared photometry obtained by the Wide-field Infrared Survey Explorer (WISE) satellite extending from 56 days prior to the optical discovery to over 1600 days. The light curve of SN 2014ab evolves slowly, while the spectra exhibit strong emission features produced from the interaction between rapidly expanding ejecta and dense circumstellar matter. The light curve and spectral properties are very similar to those of SN 2010jl. The estimated mass-loss rate of the progenitor of SN 2014ab is of the order of 0.1 Msun/yr under the assumption of spherically symmetric circumstellar matter and steady mass loss. Although the mid-infrared luminosity increases due to emission from dust, which is characterized by a blackbody temperature close to the dust evaporation temperature (~ 2000 K), no clear signatures of in situ dust formation within the cold dense shell located behind the forward shock are observed in SN 2014ab in early phases. Mid-infrared emission of SN 2014ab may originate from pre-existing dust located within dense circumstellar matter that is heated by the SN shock or shock-driven radiation. Finally, for the benefit of the community, we also present in an Appendix five near-infrared spectra of SN 2010jl obtained between 450 to 1300 days post discovery. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2006.10198v3-abstract-full').style.display = 'none'; document.getElementById('2006.10198v3-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> 15 July, 2020; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 17 June, 2020; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> June 2020. </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">22 pages, 13 figures, 6 tables, accepted by Astronomy & Astrophysics, proofed</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Astronomy & Astrophysics, Volume 641, id.A148, 17 pp. (2020) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2003.11121">arXiv:2003.11121</a> <span> [<a href="https://arxiv.org/pdf/2003.11121">pdf</a>, <a href="https://arxiv.org/format/2003.11121">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/ab8e37">10.3847/2041-8213/ab8e37 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Carnegie Supernova Project-II: A new method to photometrically identify sub-types of extreme Type Ia Supernovae </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=Lu%2C+J">J. Lu</a>, <a href="/search/astro-ph?searchtype=author&query=Burns%2C+C">C. Burns</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=Stritzinger%2C+M">M. Stritzinger</a>, <a href="/search/astro-ph?searchtype=author&query=Suntzeff%2C+N+B">N. B. Suntzeff</a>, <a href="/search/astro-ph?searchtype=author&query=Phillips%2C+M+M">M. M. Phillips</a>, <a href="/search/astro-ph?searchtype=author&query=Baron%2C+E">E. Baron</a>, <a href="/search/astro-ph?searchtype=author&query=Contreras%2C+C">C. Contreras</a>, <a href="/search/astro-ph?searchtype=author&query=Davis%2C+S">S. Davis</a>, <a href="/search/astro-ph?searchtype=author&query=Galbany%2C+L">L. Galbany</a>, <a href="/search/astro-ph?searchtype=author&query=Hoeflich%2C+P">P. Hoeflich</a>, <a href="/search/astro-ph?searchtype=author&query=Holmbo%2C+S">S. Holmbo</a>, <a href="/search/astro-ph?searchtype=author&query=Morrell%2C+N">N. Morrell</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=Shahbandeh%2C+M">M. Shahbandeh</a>, <a href="/search/astro-ph?searchtype=author&query=Uddin%2C+S">S. Uddin</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="2003.11121v3-abstract-short" style="display: inline;"> We present a new method to photometrically delineate between various sub-types of type Ia supernovae (SNe Ia). Using the color-stretch parameters, $s_{BV}$ or $s_{gr}$, and the time of i-band primary maximum relative to the B-band or g-band maximum it is demonstrated that 2003fg-like, 1991bg-like, and 2002cx-like SNe Ia can readily be identified. In the cases of these extreme SNe Ia, their primary… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2003.11121v3-abstract-full').style.display = 'inline'; document.getElementById('2003.11121v3-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2003.11121v3-abstract-full" style="display: none;"> We present a new method to photometrically delineate between various sub-types of type Ia supernovae (SNe Ia). Using the color-stretch parameters, $s_{BV}$ or $s_{gr}$, and the time of i-band primary maximum relative to the B-band or g-band maximum it is demonstrated that 2003fg-like, 1991bg-like, and 2002cx-like SNe Ia can readily be identified. In the cases of these extreme SNe Ia, their primary i-band maximum occurs after the time of the B or g band maxima. We suggest that the timing of the i-band maximum can reveal the physical state of the SN Ia explosion as it traces: i) the speed of the recombination front of iron group elements in the ejecta, ii) the temperature evolution and rate of adiabatic cooling in the ejecta and, iii) the presence of interaction with a stellar envelope. This photometric sub-typing can be used in conjunction with other SNe analysis, such as the Branch diagram, to examine the physics and diversity of SNe Ia. The results here can also be used to screen out non-Ia SNe from cosmological samples that do not have complete spectroscopic typing. Finally, as future surveys like LSST create large databases of light curves of many objects this photometric identification can be used to readily identify and study the rates and bulk properties of peculiar SNe Ia. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2003.11121v3-abstract-full').style.display = 'none'; document.getElementById('2003.11121v3-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, 2020; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 24 March, 2020; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> March 2020. </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 ApjL, one additional 03fg-like SNe add compared to the previous 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/2002.08377">arXiv:2002.08377</a> <span> [<a href="https://arxiv.org/pdf/2002.08377">pdf</a>, <a href="https://arxiv.org/format/2002.08377">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/10.1093/mnras/staa573">10.1093/mnras/staa573 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Time Dependent Radiation Hydrodynamics on a Moving Mesh </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Chang%2C+P">Philip Chang</a>, <a href="/search/astro-ph?searchtype=author&query=Davis%2C+S+W">Shane W. Davis</a>, <a href="/search/astro-ph?searchtype=author&query=Jiang%2C+Y">Yan-Fei Jiang</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="2002.08377v2-abstract-short" style="display: inline;"> We describe the structure and implementation of a radiation hydrodynamic solver for MANGA, the moving-mesh hydrodynamics module of the large-scale parallel code, Charm N-body GrAvity solver (ChaNGa). We solve the equations of time dependent radiative transfer using a reduced speed of light approximation following the algorithm of Jiang et al (2014). By writing the radiative transfer equations as a… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2002.08377v2-abstract-full').style.display = 'inline'; document.getElementById('2002.08377v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2002.08377v2-abstract-full" style="display: none;"> We describe the structure and implementation of a radiation hydrodynamic solver for MANGA, the moving-mesh hydrodynamics module of the large-scale parallel code, Charm N-body GrAvity solver (ChaNGa). We solve the equations of time dependent radiative transfer using a reduced speed of light approximation following the algorithm of Jiang et al (2014). By writing the radiative transfer equations as a generalized conservation equation, we solve the transport part of these equations on an unstructured Voronoi mesh. We then solve the source part of the radiative transfer equations following Jiang et al (2014) using an implicit solver, and couple this to the hydrodynamic equations. The use of an implicit solver ensure reliable convergence and preserves the conservation properties of these equations even in situations where the source terms are stiff due to the small coupling timescales between radiation and matter. We present the results of a limited number of test cases (energy conservation, momentum conservation, dynamic diffusion, linear waves, crossing beams, and multiple shadows) to show convergence with analytic results and numerical stability. We also show that it produces qualitatively the correct results in the presence of multiple sources in the optically thin case. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2002.08377v2-abstract-full').style.display = 'none'; document.getElementById('2002.08377v2-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 February, 2020; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 19 February, 2020; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> February 2020. </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, 8 figures, accepted 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/1911.07950">arXiv:1911.07950</a> <span> [<a href="https://arxiv.org/pdf/1911.07950">pdf</a>, <a href="https://arxiv.org/ps/1911.07950">ps</a>, <a href="https://arxiv.org/format/1911.07950">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/ab5950">10.3847/1538-4357/ab5950 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Covariant Radiative Transfer for Black Hole Spacetimes </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Davis%2C+S+W">Shane W. Davis</a>, <a href="/search/astro-ph?searchtype=author&query=Gammie%2C+C+F">Charles F. Gammie</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="1911.07950v1-abstract-short" style="display: inline;"> It has now become possible to study directly, via numerical simulation, the evolution of relativistic, radiation-dominated flows around compact objects. With this in mind we set out explicitly covariant forms of the radiative transfer equation that are suitable for numerical integration in curved spacetime or flat spacetime in curvilinear coordinates. Our work builds on and summarizes in consisten… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1911.07950v1-abstract-full').style.display = 'inline'; document.getElementById('1911.07950v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1911.07950v1-abstract-full" style="display: none;"> It has now become possible to study directly, via numerical simulation, the evolution of relativistic, radiation-dominated flows around compact objects. With this in mind we set out explicitly covariant forms of the radiative transfer equation that are suitable for numerical integration in curved spacetime or flat spacetime in curvilinear coordinates. Our work builds on and summarizes in consistent form earlier work by Lindquist, Thorne, Morita and Kaneko, and others. We give explicitly the basic equations in spherical-polar coordinates for Minkowski space and the Kerr spacetime in Kerr-Schild coordinates. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1911.07950v1-abstract-full').style.display = 'none'; document.getElementById('1911.07950v1-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 November, 2019; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> November 2019. </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">29 pages, 0 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/1910.03410">arXiv:1910.03410</a> <span> [<a href="https://arxiv.org/pdf/1910.03410">pdf</a>, <a href="https://arxiv.org/format/1910.03410">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/ab4c40">10.3847/1538-4357/ab4c40 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Carnegie Supernova Project-II: Near-infrared Spectroscopic Diversity of Type II Supernovae </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Davis%2C+S">S. Davis</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=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=Phillips%2C+M+M">M. M. Phillips</a>, <a href="/search/astro-ph?searchtype=author&query=Marion%2C+G+H">G. H. Marion</a>, <a href="/search/astro-ph?searchtype=author&query=Kirshner%2C+R+P">R. P. Kirshner</a>, <a href="/search/astro-ph?searchtype=author&query=Morrell%2C+N">N. Morrell</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=Burns%2C+C">C. Burns</a>, <a href="/search/astro-ph?searchtype=author&query=Contreras%2C+C">C. Contreras</a>, <a href="/search/astro-ph?searchtype=author&query=Stritzinger%2C+M">M. Stritzinger</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=Baron%2C+E">E. Baron</a>, <a href="/search/astro-ph?searchtype=author&query=Diamond%2C+T">T. Diamond</a>, <a href="/search/astro-ph?searchtype=author&query=Gutierrez%2C+C+P">C. P. Gutierrez</a>, <a href="/search/astro-ph?searchtype=author&query=Hamuy%2C+M">M. Hamuy</a>, <a href="/search/astro-ph?searchtype=author&query=Holmbo%2C+S">S. Holmbo</a>, <a href="/search/astro-ph?searchtype=author&query=Kasliwal%2C+M+M">M. M. Kasliwal</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=Pessi%2C+P+J">P. J. Pessi</a>, <a href="/search/astro-ph?searchtype=author&query=Piro%2C+A+L">A. L. Piro</a>, <a href="/search/astro-ph?searchtype=author&query=Prieto%2C+J+L">J. L. Prieto</a> , et al. (2 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="1910.03410v2-abstract-short" style="display: inline;"> We present $81$ near-infrared (NIR) spectra of $30$ Type II supernovae (SNe II) from the Carnegie Supernova Project-II (CSP-II), the largest such dataset published to date. We identify a number of NIR features and characterize their evolution over time. The NIR spectroscopic properties of SNe II fall into two distinct groups. This classification is first based on the strength of the He I… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1910.03410v2-abstract-full').style.display = 'inline'; document.getElementById('1910.03410v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1910.03410v2-abstract-full" style="display: none;"> We present $81$ near-infrared (NIR) spectra of $30$ Type II supernovae (SNe II) from the Carnegie Supernova Project-II (CSP-II), the largest such dataset published to date. We identify a number of NIR features and characterize their evolution over time. The NIR spectroscopic properties of SNe II fall into two distinct groups. This classification is first based on the strength of the He I $\lambda1.083\,渭$m absorption during the plateau phase; SNe II are either significantly above (spectroscopically strong) or below $50$ angstroms (spectroscopically weak) in pseudo equivalent width. However between the two groups, other properties, such as the timing of CO formation and the presence of Sr II, are also observed. Most surprisingly, the distinct weak and strong NIR spectroscopic classes correspond to SNe II with slow and fast declining light curves, respectively. These two photometric groups match the modern nomenclature of SNe IIP and IIL. Including NIR spectra previously published, 18 out of 19 SNe II follow this slow declining-spectroscopically weak and fast declining-spectroscopically strong correspondence. This is in apparent contradiction to the recent findings in the optical that slow and fast decliners show a continuous distribution of properties. The weak SNe II show a high-velocity component of helium that may be caused by a thermal excitation from a reverse-shock created by the outer ejecta interacting with the red supergiant wind, but the origin of the observed dichotomy is not understood. Further studies are crucial in determining whether the apparent differences in the NIR are due to distinct physical processes or a gap in the current data set. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1910.03410v2-abstract-full').style.display = 'none'; document.getElementById('1910.03410v2-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 October, 2019; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 8 October, 2019; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> October 2019. </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">32 pages, 17 figures, accepted 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/1908.01775">arXiv:1908.01775</a> <span> [<a href="https://arxiv.org/pdf/1908.01775">pdf</a>, <a href="https://arxiv.org/format/1908.01775">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 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/ab811b">10.3847/1538-4357/ab811b <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Dusty Cloud Acceleration with Multiband Radiation </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Huang%2C+X">Xiaoshan Huang</a>, <a href="/search/astro-ph?searchtype=author&query=Davis%2C+S+W">Shane W. Davis</a>, <a href="/search/astro-ph?searchtype=author&query=Zhang%2C+D">Dong Zhang</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="1908.01775v2-abstract-short" style="display: inline;"> We perform two-dimensional and three-dimensional simulations of cold, dense clouds, which are accelerated by radiation pressure on dust relative to a hot, diffuse background gas. We examine the relative effectiveness of acceleration by ultraviolet and infrared radiation fields, both independently and acting simultaneously on the same cloud. We study clouds that are optically thin to infrared emiss… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1908.01775v2-abstract-full').style.display = 'inline'; document.getElementById('1908.01775v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1908.01775v2-abstract-full" style="display: none;"> We perform two-dimensional and three-dimensional simulations of cold, dense clouds, which are accelerated by radiation pressure on dust relative to a hot, diffuse background gas. We examine the relative effectiveness of acceleration by ultraviolet and infrared radiation fields, both independently and acting simultaneously on the same cloud. We study clouds that are optically thin to infrared emission but with varying ultraviolet optical depths. Consistent with previous work, we find relatively efficient acceleration and long cloud survival times when the infrared band flux dominates over the ultraviolet flux. However, when ultraviolet is dominant or even a modest percentage ($\sim 5-10$\%) of the infrared irradiating flux, it can act to compress the cloud, first crushing it and then disrupting the outer layers. This drives mixing of outer regions of the dusty gas with the hot diffuse background to the point where most dust is not likely to survive or stay coupled to the gas. Hence, the cold cloud is unable to survive for a long enough timescale to experience significant acceleration before disruption even though efficient infrared cooling keeps the majority of the gas close to radiative equilibrium temperature ($T \lesssim 100$K). We discuss implications for observed systems, concluding that radiation pressure driving is most effective when the light from star-forming regions is efficiently reprocessed into the infrared. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1908.01775v2-abstract-full').style.display = 'none'; document.getElementById('1908.01775v2-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> 16 April, 2020; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 5 August, 2019; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> August 2019. </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">15 Pages, 14 Figures</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> ApJ 893 (2020) 50 </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1907.04653">arXiv:1907.04653</a> <span> [<a href="https://arxiv.org/pdf/1907.04653">pdf</a>, <a href="https://arxiv.org/format/1907.04653">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/stz1855">10.1093/mnras/stz1855 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Comparison of the optical light curves of hydrogen-rich and hydrogen-poor type II supernovae </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Pessi%2C+P+J">P. J. Pessi</a>, <a href="/search/astro-ph?searchtype=author&query=Folatelli%2C+G">G. Folatelli</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=Bersten%2C+M">M. Bersten</a>, <a href="/search/astro-ph?searchtype=author&query=Burns%2C+C">C. Burns</a>, <a href="/search/astro-ph?searchtype=author&query=Contreras%2C+C">C. Contreras</a>, <a href="/search/astro-ph?searchtype=author&query=Davis%2C+S">S. Davis</a>, <a href="/search/astro-ph?searchtype=author&query=Englert%2C+B">B. Englert</a>, <a href="/search/astro-ph?searchtype=author&query=Hamuy%2C+M">M. Hamuy</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=Martinez%2C+L">L. Martinez</a>, <a href="/search/astro-ph?searchtype=author&query=Morrell%2C+N">N. Morrell</a>, <a href="/search/astro-ph?searchtype=author&query=Phillips%2C+M+M">M. M. Phillips</a>, <a href="/search/astro-ph?searchtype=author&query=Suntzeff%2C+N">N. Suntzeff</a>, <a href="/search/astro-ph?searchtype=author&query=Stritzinger%2C+M+D">M. D. Stritzinger</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="1907.04653v2-abstract-short" style="display: inline;"> Type II supernovae (SNe II) show strong hydrogen features in their spectra throughout their whole evolution while type IIb supernovae (SNe IIb) spectra evolve from dominant hydrogen lines at early times to increasingly strong helium features later on. However, it is currently unclear whether the progenitors of these supernova (SN) types form a continuum in pre-SN hydrogen mass or whether they are… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1907.04653v2-abstract-full').style.display = 'inline'; document.getElementById('1907.04653v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1907.04653v2-abstract-full" style="display: none;"> Type II supernovae (SNe II) show strong hydrogen features in their spectra throughout their whole evolution while type IIb supernovae (SNe IIb) spectra evolve from dominant hydrogen lines at early times to increasingly strong helium features later on. However, it is currently unclear whether the progenitors of these supernova (SN) types form a continuum in pre-SN hydrogen mass or whether they are physically distinct. SN light-curve morphology directly relates to progenitor and explosion properties such as the amount of hydrogen in the envelope, the pre-SN radius, the explosion energy and the synthesized mass of radioactive material. In this work we study the morphology of the optical-wavelength light curves of hydrogen-rich SNe II and hydrogen-poor SNe IIb to test whether an observational continuum exists between the two. Using a sample of 95 SNe (73 SNe II and 22 SNe IIb), we define a range of key observational parameters and present a comparative analysis between both types. We find a lack of events that bridge the observed properties of SNe II and SNe IIb. Light curve parameters such as rise times and post-maximum decline rates and curvatures clearly separate both SN types and we therefore conclude that there is no continuum, with the two SN types forming two observationally distinct families. In the V-band a rise time of 17 days (SNe II lower, SNe IIb higher), and a magnitude difference between 30 and 40 days post explosion of 0.4 mag (SNe II lower, SNe IIb higher) serve as approximate thresholds to differentiate both types. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1907.04653v2-abstract-full').style.display = 'none'; document.getElementById('1907.04653v2-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> 16 August, 2019; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 4 July, 2019; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> July 2019. </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 figures, published in MNRAS</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> 2019MNRAS.488.4239P </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1907.01013">arXiv:1907.01013</a> <span> [<a href="https://arxiv.org/pdf/1907.01013">pdf</a>, <a href="https://arxiv.org/ps/1907.01013">ps</a>, <a href="https://arxiv.org/format/1907.01013">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/ab43e3">10.3847/1538-4357/ab43e3 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> SN 2017gmr: An energetic Type II-P supernova with asymmetries </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=Sand%2C+D+J">D. 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=Smith%2C+N">Nathan Smith</a>, <a href="/search/astro-ph?searchtype=author&query=Dastidar%2C+R">Raya Dastidar</a>, <a href="/search/astro-ph?searchtype=author&query=Sahu%2C+D+K">D. K. Sahu</a>, <a href="/search/astro-ph?searchtype=author&query=Misra%2C+K">Kuntal Misra</a>, <a href="/search/astro-ph?searchtype=author&query=Singh%2C+A">Avinash Singh</a>, <a href="/search/astro-ph?searchtype=author&query=Hiramatsu%2C+D">D. Hiramatsu</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=Hosseinzadeh%2C+G">G. Hosseinzadeh</a>, <a href="/search/astro-ph?searchtype=author&query=Wyatt%2C+S">S. Wyatt</a>, <a href="/search/astro-ph?searchtype=author&query=Vinko%2C+J">J. Vinko</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=Arcavi%2C+I">I. Arcavi</a>, <a href="/search/astro-ph?searchtype=author&query=Ashall%2C+C">Chris Ashall</a>, <a href="/search/astro-ph?searchtype=author&query=Benetti%2C+S">S. Benetti</a>, <a href="/search/astro-ph?searchtype=author&query=Berton%2C+M">Marco Berton</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=Bulla%2C+M">M. Bulla</a>, <a href="/search/astro-ph?searchtype=author&query=Burke%2C+J">J. Burke</a>, <a href="/search/astro-ph?searchtype=author&query=Chen%2C+S">S. Chen</a>, <a href="/search/astro-ph?searchtype=author&query=Chomiuk%2C+L">L. Chomiuk</a>, <a href="/search/astro-ph?searchtype=author&query=Cikota%2C+A">A. Cikota</a>, <a href="/search/astro-ph?searchtype=author&query=Congiu%2C+E">E. Congiu</a> , et al. (55 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="1907.01013v1-abstract-short" style="display: inline;"> We present high-cadence ultraviolet (UV), optical, and near-infrared (NIR) data on the luminous Type II-P supernova SN 2017gmr from hours after discovery through the first 180 days. SN 2017gmr does not show signs of narrow, high-ionization emission lines in the early optical spectra, yet the optical lightcurve evolution suggests that an extra energy source from circumstellar medium (CSM) interacti… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1907.01013v1-abstract-full').style.display = 'inline'; document.getElementById('1907.01013v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1907.01013v1-abstract-full" style="display: none;"> We present high-cadence ultraviolet (UV), optical, and near-infrared (NIR) data on the luminous Type II-P supernova SN 2017gmr from hours after discovery through the first 180 days. SN 2017gmr does not show signs of narrow, high-ionization emission lines in the early optical spectra, yet the optical lightcurve evolution suggests that an extra energy source from circumstellar medium (CSM) interaction must be present for at least 2 days after explosion. Modeling of the early lightcurve indicates a ~500R$_{\odot}$ progenitor radius, consistent with a rather compact red supergiant, and late-time luminosities indicate up to 0.130 $\pm$ 0.026 M$_{\odot}$ of $^{56}$Ni are present, if the lightcurve is solely powered by radioactive decay, although the $^{56}$Ni mass may be lower if CSM interaction contributes to the post-plateau luminosity. Prominent multi-peaked emission lines of H$伪$ and [O I] emerge after day 154, as a result of either an asymmetric explosion or asymmetries in the CSM. The lack of narrow lines within the first two days of explosion in the likely presence of CSM interaction may be an example of close, dense, asymmetric CSM that is quickly enveloped by the spherical supernova ejecta. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1907.01013v1-abstract-full').style.display = 'none'; document.getElementById('1907.01013v1-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 July, 2019; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> July 2019. </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, 25 pages, plus Appendix</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1904.08947">arXiv:1904.08947</a> <span> [<a href="https://arxiv.org/pdf/1904.08947">pdf</a>, <a href="https://arxiv.org/format/1904.08947">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="Plasma Physics">physics.plasm-ph</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/10.1063/1.5090803">10.1063/1.5090803 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Atomic Modeling of Photoionization Fronts in Nitrogen Gas </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Gray%2C+W+J">William J. Gray</a>, <a href="/search/astro-ph?searchtype=author&query=Keiter%2C+P+A">P. A. Keiter</a>, <a href="/search/astro-ph?searchtype=author&query=Lefevre%2C+H">H. Lefevre</a>, <a href="/search/astro-ph?searchtype=author&query=Patterson%2C+C+R">C. R. Patterson</a>, <a href="/search/astro-ph?searchtype=author&query=Davis%2C+J+S">J. S. Davis</a>, <a href="/search/astro-ph?searchtype=author&query=Powell%2C+K+G">K. G. Powell</a>, <a href="/search/astro-ph?searchtype=author&query=Kuranz%2C+C+C">C. C. Kuranz</a>, <a href="/search/astro-ph?searchtype=author&query=Drake%2C+R+P">R. P. Drake</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="1904.08947v1-abstract-short" style="display: inline;"> Photoionization fronts play a dominant role in many astrophysical environments, but remain difficult to achieve in a laboratory experiment. Recent papers have suggested that experiments using a nitrogen medium held at ten atmospheres of pressure that is irradiated by a source with a radiation temperature of T$_{\rm R}\sim$ 100 eV can produce viable photoionization fronts. We present a suite of one… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1904.08947v1-abstract-full').style.display = 'inline'; document.getElementById('1904.08947v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1904.08947v1-abstract-full" style="display: none;"> Photoionization fronts play a dominant role in many astrophysical environments, but remain difficult to achieve in a laboratory experiment. Recent papers have suggested that experiments using a nitrogen medium held at ten atmospheres of pressure that is irradiated by a source with a radiation temperature of T$_{\rm R}\sim$ 100 eV can produce viable photoionization fronts. We present a suite of one-dimensional numerical simulations using the \helios\ multi-material radiation hydrodynamics code that models these conditions and the formation of a photoionization front. We study the effects of varying the atomic kinetics and radiative transfer model on the hydrodynamics and ionization state of the nitrogen gas, finding that more sophisticated physics, in particular a multi-angle long characteristic radiative transfer model and a collisional-radiative atomics model, dramatically changes the atomic kinetic evolution of the gas. A photoionization front is identified by computing the ratios between the photoionization rate, the electron impact ionization rate, and the total recombination rate. We find that due to the increased electron temperatures found using more advanced physics that photoionization fronts are likely to form in our nominal model. We report results of several parameter studies. In one of these, the nitrogen pressure is fixed at ten atmospheres and varies the source radiation temperature while another fixes the temperature at 100 eV and varied the nitrogen pressure. Lower nitrogen pressures increase the likelihood of generating a photoionization front while varying the peak source temperature has little effect. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1904.08947v1-abstract-full').style.display = 'none'; document.getElementById('1904.08947v1-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 April, 2019; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> April 2019. </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, accepted to physics of plasmas</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1904.04731">arXiv:1904.04731</a> <span> [<a href="https://arxiv.org/pdf/1904.04731">pdf</a>, <a href="https://arxiv.org/ps/1904.04731">ps</a>, <a href="https://arxiv.org/format/1904.04731">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/10.1093/mnras/stz1071">10.1093/mnras/stz1071 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Gas phase SiO in the circumstellar environment of the recurrent nova T Coronae Borealis </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Evans%2C+A">A. Evans</a>, <a href="/search/astro-ph?searchtype=author&query=Pavlenko%2C+Y+V">Ya. V. Pavlenko</a>, <a href="/search/astro-ph?searchtype=author&query=Banerjee%2C+D+P+K">D. P. K. Banerjee</a>, <a href="/search/astro-ph?searchtype=author&query=Munari%2C+U">U. Munari</a>, <a href="/search/astro-ph?searchtype=author&query=Gehrz%2C+R+D">R. D. Gehrz</a>, <a href="/search/astro-ph?searchtype=author&query=Woodward%2C+C+E">C. E. Woodward</a>, <a href="/search/astro-ph?searchtype=author&query=Starrfield%2C+S">S. Starrfield</a>, <a href="/search/astro-ph?searchtype=author&query=Helton%2C+L+A">L. A. Helton</a>, <a href="/search/astro-ph?searchtype=author&query=Shahbandeh%2C+M">M. Shahbandeh</a>, <a href="/search/astro-ph?searchtype=author&query=Davis%2C+S">S. Davis</a>, <a href="/search/astro-ph?searchtype=author&query=Dallaporta%2C+S">S. Dallaporta</a>, <a href="/search/astro-ph?searchtype=author&query=Cherini%2C+G">G. Cherini</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="1904.04731v1-abstract-short" style="display: inline;"> We report the discovery of the diatomic molecule SiO in the gas phase in the environment of the recurrent nova T Coronae Borealis. While some of the SiO is photospheric, a substantial portion must arise in the wind from the red giant component of T CrB. A simple fit to the SiO feature, assuming local thermodynamic equilibrium, suggests a SiO column density of 2.8x10^17 /cm2 and temperature ~1000K;… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1904.04731v1-abstract-full').style.display = 'inline'; document.getElementById('1904.04731v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1904.04731v1-abstract-full" style="display: none;"> We report the discovery of the diatomic molecule SiO in the gas phase in the environment of the recurrent nova T Coronae Borealis. While some of the SiO is photospheric, a substantial portion must arise in the wind from the red giant component of T CrB. A simple fit to the SiO feature, assuming local thermodynamic equilibrium, suggests a SiO column density of 2.8x10^17 /cm2 and temperature ~1000K; the SiO column density is similar to that present in the winds of field red giants. A search for SiO maser emission is encouraged both before and after the next anticipated eruption. We find that the 12C/13C ratio in the red giant is <9, with a best fit value of ~5, a factor ~18 times lower than the solar value of 89. We find no convincing evidence for the presence of dust in the environment of T CrB, which we attribute to the destructive effects on nucleation sites of hard X-ray emission. When the next eruption of T CrB occurs, the ejected material will shock the wind, producing X-ray and coronal line emission, as is the case for the recurrent nova RS Oph. T CrB is also a good candidate for very high energy gamma-ray emission, as first observed during the 2010 outburst of V407 Cyg. We include in the paper a wide variety of infrared spectroscopic and photometric data. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1904.04731v1-abstract-full').style.display = 'none'; document.getElementById('1904.04731v1-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 April, 2019; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> April 2019. </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 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/1904.01674">arXiv:1904.01674</a> <span> [<a href="https://arxiv.org/pdf/1904.01674">pdf</a>, <a href="https://arxiv.org/format/1904.01674">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/ab4a00">10.3847/1538-4357/ab4a00 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Global Radiation Magneto-hydrodynamic Simulations of Sub-Eddington Accretion Disks around Supermassive Black Holes </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Jiang%2C+Y">Yan-Fei Jiang</a>, <a href="/search/astro-ph?searchtype=author&query=Blaes%2C+O">Omer Blaes</a>, <a href="/search/astro-ph?searchtype=author&query=Stone%2C+J">James Stone</a>, <a href="/search/astro-ph?searchtype=author&query=Davis%2C+S+W">Shane W. Davis</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="1904.01674v1-abstract-short" style="display: inline;"> We use global three dimensional radiation magneto-hydrodynamic simulations to study the properties of inner regions of accretion disks around a 5\times 10^8 solar mass black hole with mass accretion rates reaching 7% and 20% of the Eddington value. This region of the disk is supported by magnetic pressure with surface density significantly smaller than the values predicted by the standard thin dis… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1904.01674v1-abstract-full').style.display = 'inline'; document.getElementById('1904.01674v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1904.01674v1-abstract-full" style="display: none;"> We use global three dimensional radiation magneto-hydrodynamic simulations to study the properties of inner regions of accretion disks around a 5\times 10^8 solar mass black hole with mass accretion rates reaching 7% and 20% of the Eddington value. This region of the disk is supported by magnetic pressure with surface density significantly smaller than the values predicted by the standard thin disk model but with a much larger disk scale height. The disks do not show any sign of thermal instability over many thermal time scales. More than half of the accretion is driven by radiation viscosity in the optically thin corona region for the lower accretion rate case, while accretion in the optically thick part of the disk is driven by the Maxwell and Reynolds stresses from MRI turbulence. Coronae with gas temperatures > 10^8 K are generated only in the inner \approx 10 gravitational radii in both simulations, being more compact in the higher accretion rate case. In contrast to the thin disk model, surface density increases with increasing mass accretion rate, which causes less dissipation in the optically thin region and a relatively weaker corona. The simulation results may explain the formation of X-ray coronae in Active Galactic Nuclei (AGNs), the compact size of such coronae, and the observed trend of optical to X-ray luminosity with Eddington ratio for many AGNs. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1904.01674v1-abstract-full').style.display = 'none'; document.getElementById('1904.01674v1-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, 2019; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> April 2019. </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, 12 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/1904.01633">arXiv:1904.01633</a> <span> [<a href="https://arxiv.org/pdf/1904.01633">pdf</a>, <a href="https://arxiv.org/format/1904.01633">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/ab204b">10.3847/1538-4357/ab204b <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> A Physical Basis for the H-band Blue-edge Velocity and Light-Curve Shape Correlation in Context of Type Ia Supernova Explosion Physics </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=Hsiao%2C+E+Y">E. Y. Hsiao</a>, <a href="/search/astro-ph?searchtype=author&query=Phillips%2C+M+M">M. M. Phillips</a>, <a href="/search/astro-ph?searchtype=author&query=Stritzinger%2C+M">M. Stritzinger</a>, <a href="/search/astro-ph?searchtype=author&query=Baron%2C+E">E. Baron</a>, <a href="/search/astro-ph?searchtype=author&query=Piro%2C+A+L">A. L. Piro</a>, <a href="/search/astro-ph?searchtype=author&query=Burns%2C+C">C. Burns</a>, <a href="/search/astro-ph?searchtype=author&query=Contreras%2C+C">C. Contreras</a>, <a href="/search/astro-ph?searchtype=author&query=Davis%2C+S">S. Davis</a>, <a href="/search/astro-ph?searchtype=author&query=Galbany%2C+L">L. Galbany</a>, <a href="/search/astro-ph?searchtype=author&query=Holmbo%2C+S">S. Holmbo</a>, <a href="/search/astro-ph?searchtype=author&query=Kirshner%2C+R+P">R. P. Kirshner</a>, <a href="/search/astro-ph?searchtype=author&query=Krisciunas%2C+K">K. Krisciunas</a>, <a href="/search/astro-ph?searchtype=author&query=Marion%2C+G+H">G. H. Marion</a>, <a href="/search/astro-ph?searchtype=author&query=Morrell%2C+N">N. Morrell</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=Shahbandeh%2C+M">M. Shahbandeh</a>, <a href="/search/astro-ph?searchtype=author&query=Suntzeff%2C+N+B">N. B. Suntzeff</a>, <a href="/search/astro-ph?searchtype=author&query=Taddia%2C+F">F. Taddia</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="1904.01633v3-abstract-short" style="display: inline;"> Our recent work demonstrates a correlation between the high-velocity blue edge, $v_{edge}$, of the iron-peak Fe/Co/Ni $H$-band emission feature and the optical light curve shape of normal, transitional and sub-luminous type Ia Supernovae (SNe Ia). We explain this correlation in terms of SN Ia physics. $v_{edge}$ corresponds to the sharp transition between the complete and incomplete silicon burnin… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1904.01633v3-abstract-full').style.display = 'inline'; document.getElementById('1904.01633v3-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1904.01633v3-abstract-full" style="display: none;"> Our recent work demonstrates a correlation between the high-velocity blue edge, $v_{edge}$, of the iron-peak Fe/Co/Ni $H$-band emission feature and the optical light curve shape of normal, transitional and sub-luminous type Ia Supernovae (SNe Ia). We explain this correlation in terms of SN Ia physics. $v_{edge}$ corresponds to the sharp transition between the complete and incomplete silicon burning regions in the ejecta. It measures the point in velocity space where the outer $^{56}$Ni mass fraction, $X_{\rm{Ni}}$, falls to the order of 0.03-0.10. For a given $^{56}$Ni mass, $M(^{56}Ni)$, $v_{edge}$ is sensitive to the specific kinetic energy $E_{\rm kin}$($M(^{56}Ni)/M_{WD}$) of the corresponding region. Combining $v_{edge}$ with light curve parameters (i.e., s$_{BV}$, $螖m_{15,s}$ in $B$ and $V$) allows us to distinguish between explosion scenarios. The correlation between $v_{edge}$ and light-curve shape is consistent with explosion models near the Chandrasekhar limit. However, the available sub-$M_{Ch}$ WD explosion model based on SN 1999by exhibits velocities which are too large to explain the observations. Finally, the sub-luminous SN 2015bo exhibits signatures of a dynamical merger of two WDs demonstrating diversity among explosion scenarios at the faint end of the SNe Ia population. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1904.01633v3-abstract-full').style.display = 'none'; document.getElementById('1904.01633v3-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 May, 2019; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 2 April, 2019; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> April 2019. </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 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/1902.10088">arXiv:1902.10088</a> <span> [<a href="https://arxiv.org/pdf/1902.10088">pdf</a>, <a href="https://arxiv.org/format/1902.10088">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/ab1654">10.3847/2041-8213/ab1654 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Carnegie Supernova Project-II: Using Near-Infrared Spectroscopy to determine the location of the outer $^{56}$Ni in Type Ia Supernovae </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=Hsiao%2C+E+Y">E. Y. Hsiao</a>, <a href="/search/astro-ph?searchtype=author&query=Hoeflich%2C+P">P. Hoeflich</a>, <a href="/search/astro-ph?searchtype=author&query=Stritzinger%2C+M">M. Stritzinger</a>, <a href="/search/astro-ph?searchtype=author&query=Phillips%2C+M+M">M. M. Phillips</a>, <a href="/search/astro-ph?searchtype=author&query=Morrell%2C+N">N. Morrell</a>, <a href="/search/astro-ph?searchtype=author&query=Davis%2C+S">S. Davis</a>, <a href="/search/astro-ph?searchtype=author&query=Baron%2C+E">E. Baron</a>, <a href="/search/astro-ph?searchtype=author&query=Piro%2C+A+L">A. L. Piro</a>, <a href="/search/astro-ph?searchtype=author&query=Burns%2C+C">C. Burns</a>, <a href="/search/astro-ph?searchtype=author&query=Contreras%2C+C">C. Contreras</a>, <a href="/search/astro-ph?searchtype=author&query=Galbany%2C+L">L. Galbany</a>, <a href="/search/astro-ph?searchtype=author&query=Holmbo%2C+S">S. Holmbo</a>, <a href="/search/astro-ph?searchtype=author&query=Kirshner%2C+R+P">R. P. Kirshner</a>, <a href="/search/astro-ph?searchtype=author&query=Krisciunas%2C+K">K. Krisciunas</a>, <a href="/search/astro-ph?searchtype=author&query=Marion%2C+G+H">G. H. Marion</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=Shahbandeh%2C+M">M. Shahbandeh</a>, <a href="/search/astro-ph?searchtype=author&query=Suntzeff%2C+N+B">N. B. Suntzeff</a>, <a href="/search/astro-ph?searchtype=author&query=Taddia%2C+F">F. Taddia</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="1902.10088v2-abstract-short" style="display: inline;"> We present the $H$-band wavelength region of thirty post-maximum light near-infrared (NIR) spectra of fourteen transitional and sub-luminous type Ia supernovae (SNe Ia), extending from $+$5d to +20d relative to the epoch of $B$-band maximum. We introduce a new observable, the blue-edge velocity, $v_{edge}$, of the prominent Fe/Co/Ni-peak $H$-band emission feature which is quantitatively measured.… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1902.10088v2-abstract-full').style.display = 'inline'; document.getElementById('1902.10088v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1902.10088v2-abstract-full" style="display: none;"> We present the $H$-band wavelength region of thirty post-maximum light near-infrared (NIR) spectra of fourteen transitional and sub-luminous type Ia supernovae (SNe Ia), extending from $+$5d to +20d relative to the epoch of $B$-band maximum. We introduce a new observable, the blue-edge velocity, $v_{edge}$, of the prominent Fe/Co/Ni-peak $H$-band emission feature which is quantitatively measured. The $v_{edge}$ parameter is found to slowly decrease over sub-type ranging from around $-$13,000km/s for transitional SNe~Ia, down to $-$5,000km/s for the sub-luminous SNe Ia. Furthermore, inspection of the +10$\pm$3d spectra indicates that $v_{edge}$ is correlated with the color-stretch parameter, s$_{BV}$, and hence with peak luminosity. These results follow the previous findings that brighter SNe Ia tend to have $^{56}$Ni located at higher velocities as compared to sub-luminous objects. As $v_{edge}$ is a model-independent parameter, we propose it can be used in combination with traditional observational diagnostics to provide a new avenue to robustly distinguish between leading SNe Ia explosion models. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1902.10088v2-abstract-full').style.display = 'none'; document.getElementById('1902.10088v2-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 April, 2019; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 26 February, 2019; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> February 2019. </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 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/1810.08213">arXiv:1810.08213</a> <span> [<a href="https://arxiv.org/pdf/1810.08213">pdf</a>, <a href="https://arxiv.org/ps/1810.08213">ps</a>, <a href="https://arxiv.org/format/1810.08213">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/10.1088/1538-3873/aae961">10.1088/1538-3873/aae961 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Carnegie Supernova Project-II: The Near-infrared Spectroscopy Program </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Hsiao%2C+E+Y">E. Y. Hsiao</a>, <a href="/search/astro-ph?searchtype=author&query=Phillips%2C+M+M">M. M. Phillips</a>, <a href="/search/astro-ph?searchtype=author&query=Marion%2C+G+H">G. H. Marion</a>, <a href="/search/astro-ph?searchtype=author&query=Kirshner%2C+R+P">R. P. Kirshner</a>, <a href="/search/astro-ph?searchtype=author&query=Morrell%2C+N">N. Morrell</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=Burns%2C+C+R">C. R. Burns</a>, <a href="/search/astro-ph?searchtype=author&query=Contreras%2C+C">C. Contreras</a>, <a href="/search/astro-ph?searchtype=author&query=Hoeflich%2C+P">P. Hoeflich</a>, <a href="/search/astro-ph?searchtype=author&query=Stritzinger%2C+M+D">M. D. Stritzinger</a>, <a href="/search/astro-ph?searchtype=author&query=Valenti%2C+S">S. Valenti</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=Ashall%2C+C">C. Ashall</a>, <a href="/search/astro-ph?searchtype=author&query=Baltay%2C+C">C. Baltay</a>, <a href="/search/astro-ph?searchtype=author&query=Baron%2C+E">E. Baron</a>, <a href="/search/astro-ph?searchtype=author&query=Banerjee%2C+D+P+K">D. P. K. Banerjee</a>, <a href="/search/astro-ph?searchtype=author&query=Davis%2C+S">S. Davis</a>, <a href="/search/astro-ph?searchtype=author&query=Diamond%2C+T+R">T. R. Diamond</a>, <a href="/search/astro-ph?searchtype=author&query=Folatelli%2C+G">G. Folatelli</a>, <a href="/search/astro-ph?searchtype=author&query=Freedman%2C+W+L">Wendy L. Freedman</a>, <a href="/search/astro-ph?searchtype=author&query=F%C3%B6rster%2C+F">F. F枚rster</a>, <a href="/search/astro-ph?searchtype=author&query=Galbany%2C+L">L. Galbany</a>, <a href="/search/astro-ph?searchtype=author&query=Gall%2C+C">C. Gall</a>, <a href="/search/astro-ph?searchtype=author&query=Gonz%C3%A1lez-Gait%C3%A1n%2C+S">S. Gonz谩lez-Gait谩n</a>, <a href="/search/astro-ph?searchtype=author&query=Goobar%2C+A">A. Goobar</a> , et al. (20 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="1810.08213v2-abstract-short" style="display: inline;"> Shifting the focus of Type Ia supernova (SN Ia) cosmology to the near-infrared (NIR) is a promising way to significantly reduce the systematic errors, as the strategy minimizes our reliance on the empirical width-luminosity relation and uncertain dust laws. Observations in the NIR are also crucial for our understanding of the origins and evolution of these events, further improving their cosmologi… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1810.08213v2-abstract-full').style.display = 'inline'; document.getElementById('1810.08213v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1810.08213v2-abstract-full" style="display: none;"> Shifting the focus of Type Ia supernova (SN Ia) cosmology to the near-infrared (NIR) is a promising way to significantly reduce the systematic errors, as the strategy minimizes our reliance on the empirical width-luminosity relation and uncertain dust laws. Observations in the NIR are also crucial for our understanding of the origins and evolution of these events, further improving their cosmological utility. Any future experiments in the rest-frame NIR will require knowledge of the SN Ia NIR spectroscopic diversity, which is currently based on a small sample of observed spectra. Along with the accompanying paper, Phillips et al. (2018), we introduce the Carnegie Supernova Project-II (CSP-II), to follow up nearby SNe Ia in both the optical and the NIR. In particular, this paper focuses on the CSP-II NIR spectroscopy program, describing the survey strategy, instrumental setups, data reduction, sample characteristics, and future analyses on the data set. In collaboration with the Harvard-Smithsonian Center for Astrophysics (CfA) Supernova Group, we obtained 661 NIR spectra of 157 SNe Ia. Within this sample, 451 NIR spectra of 90 SNe Ia have corresponding CSP-II follow-up light curves. Such a sample will allow detailed studies of the NIR spectroscopic properties of SNe Ia, providing a different perspective on the properties of the unburned material, radioactive and stable nickel produced, progenitor magnetic fields, and searches for possible signatures of companion stars. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1810.08213v2-abstract-full').style.display = 'none'; document.getElementById('1810.08213v2-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 December, 2018; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 18 October, 2018; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> October 2018. </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, 7 figures, accepted for publication in PASP</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1809.05134">arXiv:1809.05134</a> <span> [<a href="https://arxiv.org/pdf/1809.05134">pdf</a>, <a href="https://arxiv.org/format/1809.05134">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/ab05c5">10.3847/1538-4357/ab05c5 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Spectral Hardening in Black Hole Accretion: Giving Spectral Modelers an f </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Davis%2C+S+W">Shane W. Davis</a>, <a href="/search/astro-ph?searchtype=author&query=El-Abd%2C+S">Samer El-Abd</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="1809.05134v1-abstract-short" style="display: inline;"> By fitting synthetic spectral models computed via the TLUSTY code, we examine how the spectra from thin accretion disks are expected to vary in accreting black hole systems. We fit color-corrected blackbody models to our synthetic spectra to estimate the spectral hardening factor f, which parameterizes the departure from blackbody and is commonly used to help interpret multitemperature blackbody f… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1809.05134v1-abstract-full').style.display = 'inline'; document.getElementById('1809.05134v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1809.05134v1-abstract-full" style="display: none;"> By fitting synthetic spectral models computed via the TLUSTY code, we examine how the spectra from thin accretion disks are expected to vary in accreting black hole systems. We fit color-corrected blackbody models to our synthetic spectra to estimate the spectral hardening factor f, which parameterizes the departure from blackbody and is commonly used to help interpret multitemperature blackbody fitting results. We find we can define a reasonably robust f value to spectra when the effects of Compton scattering dominate radiation transfer. We examine the evolution of f with black hole mass and accretion rate, typically finding a moderate variation (f ~ 1.4-2) for accretion rates between 1% and 100% of the Eddington rate. Consistent with most previous work, we find f tends to increase with accretion rate, but we also infer a weaker correlation of f with black holes mass. We find that f is rarely much larger than 2 unless the disk becomes photon starved, in contention with some previous calculations. Significant spectral hardening (f > 2) is only found when the disk mass surface density is lower than expected for alpha-disk models unless alpha is near unity or larger. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1809.05134v1-abstract-full').style.display = 'none'; document.getElementById('1809.05134v1-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 September, 2018; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> September 2018. </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">9 pages, 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/1804.01539">arXiv:1804.01539</a> <span> [<a href="https://arxiv.org/pdf/1804.01539">pdf</a>, <a href="https://arxiv.org/format/1804.01539">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="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/aabc0f">10.3847/1538-4357/aabc0f <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Laboratory Photoionization Fronts in Nitrogen Gas: A Numerical Feasibility and Parameter Study </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Gray%2C+W+J">William J Gray</a>, <a href="/search/astro-ph?searchtype=author&query=Keiter%2C+P+A">P. A. Keiter</a>, <a href="/search/astro-ph?searchtype=author&query=Lefevre%2C+H">H. Lefevre</a>, <a href="/search/astro-ph?searchtype=author&query=Patterson%2C+C+R">C. R. Patterson</a>, <a href="/search/astro-ph?searchtype=author&query=Davis%2C+J+S">J. S. Davis</a>, <a href="/search/astro-ph?searchtype=author&query=van+Der+Holst%2C+B">B. van Der Holst</a>, <a href="/search/astro-ph?searchtype=author&query=Powell%2C+K+G">K. G. Powell</a>, <a href="/search/astro-ph?searchtype=author&query=Drake%2C+R+P">R. P. Drake</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="1804.01539v1-abstract-short" style="display: inline;"> Photoionization fronts play a dominant role in many astrophysical situations, but remain difficult to achieve in a laboratory experiment. We present the results from a computational parameter study evaluating the feasibility of the photoionization experiment presented in the design paper by Drake, R. P., Hazak, G., Keiter, P. A., Davis, J. S., Patterson, C. R., Frank, A., Blackman, E. G., & Busque… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1804.01539v1-abstract-full').style.display = 'inline'; document.getElementById('1804.01539v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1804.01539v1-abstract-full" style="display: none;"> Photoionization fronts play a dominant role in many astrophysical situations, but remain difficult to achieve in a laboratory experiment. We present the results from a computational parameter study evaluating the feasibility of the photoionization experiment presented in the design paper by Drake, R. P., Hazak, G., Keiter, P. A., Davis, J. S., Patterson, C. R., Frank, A., Blackman, E. G., & Busquet, M. 2016, ApJ, 833, 249 in which a photoionization front is generated in a nitrogen medium . The nitrogen gas density and the Planckian radiation temperature of the x-ray source define each simulation. Simulations modeled experiments in which the x-ray flux is generated by a laser-heated gold foil, suitable for experiments using many kJ of laser energy, and experiments in which the flux is generated by a "z-pinch" device, which implodes a cylindrical shell of conducting wires. The models are run using CRASH, our block-adaptive-mesh code for multi-material radiation hydrodynamics. The radiative transfer model uses multi-group, flux-limited diffusion with thirty radiation groups. In addition, electron heat conduction is modeled using a single-group, flux-limited diffusion. In the theory, a photoionization front can exist only when the ratios of the electron recombination rate to the photoionization rate and the electron impact ionization rate to the recombination rate lie in certain ranges. These ratios are computed for several ionization states of nitrogen. Photoionization fronts are found to exist for laser driven models with moderate nitrogen densities ($\sim$10$^{21}$ cm$^{-3}$) and radiation temperatures above 90 eV. For "z-pinch" driven models, lower nitrogen densities are preferred ($<$10$^{21}$ cm$^{-3}$). We conclude that the proposed experiments are likely to generate photoionization fronts. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1804.01539v1-abstract-full').style.display = 'none'; document.getElementById('1804.01539v1-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 April, 2018; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> April 2018. </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">22 pages, 14 figures, 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/1804.01333">arXiv:1804.01333</a> <span> [<a href="https://arxiv.org/pdf/1804.01333">pdf</a>, <a href="https://arxiv.org/ps/1804.01333">ps</a>, <a href="https://arxiv.org/format/1804.01333">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/10.1051/0004-6361/201832717">10.1051/0004-6361/201832717 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Infrared spectroscopy of the merger candidate KIC 9832227 </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Pavlenko%2C+Y+V">Ya. V. Pavlenko</a>, <a href="/search/astro-ph?searchtype=author&query=Evans%2C+A">A. Evans</a>, <a href="/search/astro-ph?searchtype=author&query=Banerjee%2C+D+P+K">D. P. K. Banerjee</a>, <a href="/search/astro-ph?searchtype=author&query=Southworth%2C+J">J. Southworth</a>, <a href="/search/astro-ph?searchtype=author&query=Shahbandeh%2C+M">M. Shahbandeh</a>, <a href="/search/astro-ph?searchtype=author&query=Davis%2C+S">S. Davis</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="1804.01333v1-abstract-short" style="display: inline;"> Context: It has been predicted that the object KIC 9832227 - a contact binary star - will undergo a merger in 2022.2+/-0.7. We describe the near infrared spectrum of this object as an impetus to obtain pre-merger data. Aims: We aim to characterise (i)~the nature of the individual components of the binary and (ii)~the likely circumbinary environment, so that the merger - if and when it occurs - c… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1804.01333v1-abstract-full').style.display = 'inline'; document.getElementById('1804.01333v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1804.01333v1-abstract-full" style="display: none;"> Context: It has been predicted that the object KIC 9832227 - a contact binary star - will undergo a merger in 2022.2+/-0.7. We describe the near infrared spectrum of this object as an impetus to obtain pre-merger data. Aims: We aim to characterise (i)~the nature of the individual components of the binary and (ii)~the likely circumbinary environment, so that the merger - if and when it occurs - can be interpreted in an informed manner. Methods: We use infrared spectroscopy in the wavelength range 0.7micron - 2.5microns, to which we fit model atmospheres to represent the individual stars. We use the binary ephemeris to determine the orbital phase at the time of observation. Results: We find that the infrared spectrum is best fitted by a single component having effective temperature 5920K, log[g]=4.1 and solar metallicity, consistent with the fact that the system was observed at conjunction. Conclusions: The strength of the infrared H lines is consistent with a high value of log[g], and the strength of the CaII triplet indicates the presence of a chromosphere, as might be expected from rapid stellar rotation. The HeI absorption we observe likely arises in He excited by coronal activity in a circumstellar envelope, suggesting that the weakness of the CaII triplet is also likely chromospheric in origin. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1804.01333v1-abstract-full').style.display = 'none'; document.getElementById('1804.01333v1-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 April, 2018; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> April 2018. </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 Astronomy & Astrophysics</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> A&A 615, A120 (2018) </p> 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