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</div> <div class="control"> <button class="button is-small is-link">Go</button> </div> </div> </form> </div> </div> <nav class="pagination is-small is-centered breathe-horizontal" role="navigation" aria-label="pagination"> <a href="" class="pagination-previous is-invisible">Previous </a> <a href="/search/?searchtype=author&query=Krisciunas%2C+K&start=50" class="pagination-next" >Next </a> <ul class="pagination-list"> <li> <a href="/search/?searchtype=author&query=Krisciunas%2C+K&start=0" class="pagination-link is-current" aria-label="Goto page 1">1 </a> </li> <li> <a href="/search/?searchtype=author&query=Krisciunas%2C+K&start=50" class="pagination-link " aria-label="Page 2" aria-current="page">2 </a> </li> <li> <a href="/search/?searchtype=author&query=Krisciunas%2C+K&start=100" class="pagination-link " aria-label="Page 3" aria-current="page">3 </a> </li> </ul> </nav> <ol class="breathe-horizontal" start="1"> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2411.02401">arXiv:2411.02401</a> <span> [<a href="https://arxiv.org/pdf/2411.02401">pdf</a>, <a href="https://arxiv.org/ps/2411.02401">ps</a>, <a href="https://arxiv.org/format/2411.02401">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="Popular Physics">physics.pop-ph</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Physics and Society">physics.soc-ph</span> </div> </div> <p class="title is-5 mathjax"> A Civilian Astronomer's Guide to UAP Research </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Villarroel%2C+B">Beatriz Villarroel</a>, <a href="/search/astro-ph?searchtype=author&query=Krisciunas%2C+K">Kevin Krisciunas</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="2411.02401v1-abstract-short" style="display: inline;"> Unidentified Anomalous Phenomena (UAP) have historically been stigmatized and regarded as pseudoscience due to a general lack of robust evidence. Recently, however, the subject has gained interest among astronomers and the military. This review explores how astronomers can enhance our understanding of these enigmatic phenomena by focusing on empirical tests of specific hypotheses (e.g. the hypothe… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2411.02401v1-abstract-full').style.display = 'inline'; document.getElementById('2411.02401v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2411.02401v1-abstract-full" style="display: none;"> Unidentified Anomalous Phenomena (UAP) have historically been stigmatized and regarded as pseudoscience due to a general lack of robust evidence. Recently, however, the subject has gained interest among astronomers and the military. This review explores how astronomers can enhance our understanding of these enigmatic phenomena by focusing on empirical tests of specific hypotheses (e.g. the hypothesis of extraterrestrial visitations) rather than solely collecting and categorizing data. We compare the investigation of UAP to the process of calibration and interpretations of astronomical discoveries and propose a toy model involving a network of neuro-interface extraterrestrial probes to model exotic UAP. This model aids in predicting probe signatures and behaviour, improving detection methods, and addressing ethical concerns in UAP research. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2411.02401v1-abstract-full').style.display = 'none'; document.getElementById('2411.02401v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 17 October, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> November 2024. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">Submitted. Constructive 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/2410.06738">arXiv:2410.06738</a> <span> [<a href="https://arxiv.org/pdf/2410.06738">pdf</a>, <a href="https://arxiv.org/format/2410.06738">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"> Optical and near-infrared photometry of 94 type II supernovae from the Carnegie Supernova Project </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Anderson%2C+J+P">J. P. Anderson</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+D">M. D. Stritzinger</a>, <a href="/search/astro-ph?searchtype=author&query=Hamuy%2C+M">M. Hamuy</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+B">N. B. Suntzeff</a>, <a href="/search/astro-ph?searchtype=author&query=Morrell%2C+N">N. Morrell</a>, <a href="/search/astro-ph?searchtype=author&query=Gonzalez-Gaitan%2C+S">S. Gonzalez-Gaitan</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=Burns%2C+C+R">C. R. 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=Anais%2C+J">J. Anais</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=Bersten%2C+M">M. Bersten</a>, <a href="/search/astro-ph?searchtype=author&query=Busta%2C+L">L. Busta</a>, <a href="/search/astro-ph?searchtype=author&query=Castellon%2C+S">S. Castellon</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=DePoy%2C+D">D. DePoy</a>, <a href="/search/astro-ph?searchtype=author&query=Filippenko%2C+A+V">A. V. Filippenko</a>, <a href="/search/astro-ph?searchtype=author&query=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=Galbany%2C+L">L. Galbany</a>, <a href="/search/astro-ph?searchtype=author&query=Gall%2C+C">C. Gall</a> , et al. (21 additional authors not shown) </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2410.06738v1-abstract-short" style="display: inline;"> Type II supernovae (SNeII) mark the endpoint in the lives of hydrogen-rich massive stars. Their large explosion energies and luminosities allow us to measure distances, metallicities, and star formation rates into the distant Universe. To fully exploit their use in answering different astrophysical problems, high-quality low-redshift data sets are required. Such samples are vital to understand the… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2410.06738v1-abstract-full').style.display = 'inline'; document.getElementById('2410.06738v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2410.06738v1-abstract-full" style="display: none;"> Type II supernovae (SNeII) mark the endpoint in the lives of hydrogen-rich massive stars. Their large explosion energies and luminosities allow us to measure distances, metallicities, and star formation rates into the distant Universe. To fully exploit their use in answering different astrophysical problems, high-quality low-redshift data sets are required. Such samples are vital to understand the physics of SNeII, but also to serve as calibrators for distinct - and often lower-quality - samples. We present uBgVri optical and YJH near-infrared (NIR) photometry for 94 low-redshift SNeII observed by the Carnegie Supernova Project (CSP). A total of 9817 optical and 1872 NIR photometric data points are released, leading to a sample of high-quality SNII light curves during the first ~150 days post explosion on a well-calibrated photometric system. The sample is presented and its properties are analysed and discussed through comparison to literature events. We also focus on individual SNeII as examples of classically defined subtypes and outlier objects. Making a cut in the plateau decline rate of our sample (s2), a new subsample of fast-declining SNeII is presented. The sample has a median redshift of 0.015, with the nearest event at 0.001 and the most distant at 0.07. At optical wavelengths (V), the sample has a median cadence of 4.7 days over the course of a median coverage of 80 days. In the NIR (J), the median cadence is 7.2 days over the course of 59 days. The fast-declining subsample is more luminous than the full sample and shows shorter plateau phases. Of the non-standard SNeII highlighted, SN2009A particularly stands out with a steeply declining then rising light curve, together with what appears to be two superimposed P-Cygni profiles of H-alpha in its spectra. We outline the significant utility of these data, and finally provide an outlook of future SNII science. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2410.06738v1-abstract-full').style.display = 'none'; document.getElementById('2410.06738v1-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 October, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> October 2024. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">Accepted for publication in A&A. Photometric data will be uploaded to the CDS and the CSP website, and can also be requested from the first author</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2405.15027">arXiv:2405.15027</a> <span> [<a href="https://arxiv.org/pdf/2405.15027">pdf</a>, <a href="https://arxiv.org/ps/2405.15027">ps</a>, <a href="https://arxiv.org/format/2405.15027">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"> 1991T-like Supernovae </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Phillips%2C+M+M">M. M. Phillips</a>, <a href="/search/astro-ph?searchtype=author&query=Ashall%2C+C">C. Ashall</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=Galbany%2C+L">L. Galbany</a>, <a href="/search/astro-ph?searchtype=author&query=Tucker%2C+M+A">M. A. Tucker</a>, <a href="/search/astro-ph?searchtype=author&query=Burns%2C+C+R">Christopher R. Burns</a>, <a href="/search/astro-ph?searchtype=author&query=Contreras%2C+C">Carlos Contreras</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=Kumar%2C+S">S. Kumar</a>, <a href="/search/astro-ph?searchtype=author&query=Morrell%2C+N">Nidia Morrell</a>, <a href="/search/astro-ph?searchtype=author&query=Uddin%2C+S+A">Syed A. Uddin</a>, <a href="/search/astro-ph?searchtype=author&query=Baron%2C+E">E. Baron</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=Krisciunas%2C+K">Kevin Krisciunas</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=Shappee%2C+B+J">B. J. Shappee</a>, <a href="/search/astro-ph?searchtype=author&query=Stritzinger%2C+M">Maximilian 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=Chakraborty%2C+S">Sudeshna Chakraborty</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=Lu%2C+J">J. 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=Polin%2C+A">Abigail Polin</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="2405.15027v1-abstract-short" style="display: inline;"> Understanding the nature of the luminous 1991T-like supernovae is of great importance to supernova cosmology as they are likely to have been more common in the early universe. In this paper we explore the observational properties of 1991T-like supernovae to study their relationship to other luminous, slow-declining Type~Ia supernovae (SNe Ia). From the spectroscopic and photometric criteria define… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2405.15027v1-abstract-full').style.display = 'inline'; document.getElementById('2405.15027v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2405.15027v1-abstract-full" style="display: none;"> Understanding the nature of the luminous 1991T-like supernovae is of great importance to supernova cosmology as they are likely to have been more common in the early universe. In this paper we explore the observational properties of 1991T-like supernovae to study their relationship to other luminous, slow-declining Type~Ia supernovae (SNe Ia). From the spectroscopic and photometric criteria defined in Phillips et al. (1992), we identify 17 1991T-like supernovae from the literature. Combining these objects with ten 1991T-like supernovae from the Carnegie Supernova Project-II, the spectra, light curves, and colors of these events, along with their host galaxy properties, are examined in detail. We conclude that 1991T-like supernovae are closely related in essentially all of their UV, optical, and near-infrared properties -- as well as their host galaxy parameters -- to the slow-declining subset of Branch core-normal supernovae and to the intermediate 1999aa-like events, forming a continuum of luminous SNe Ia. The overriding difference between these three subgroups appears to be the extent to which $^{56}$Ni mixes into the ejecta, producing the pre-maximum spectra dominated by Fe III absorption, the broader UV light curves, and the higher luminosities that characterize the 1991T-like events. Nevertheless, the association of 1991T-like SNe with the rare Type Ia CSM supernovae would seem to run counter to this hypothesis, in which case 1991T-like events may form a separate subclass of SNe Ia, possibly arising from single-degenerate progenitor systems. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2405.15027v1-abstract-full').style.display = 'none'; document.getElementById('2405.15027v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 23 May, 2024; <span class="has-text-black-bis has-text-weight-semibold">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">Accepted for publication in ApJS</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2404.19208">arXiv:2404.19208</a> <span> [<a href="https://arxiv.org/pdf/2404.19208">pdf</a>, <a href="https://arxiv.org/format/2404.19208">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"> Optical Spectroscopy of Type Ia Supernovae by the Carnegie Supernova Projects I and II </p> <p class="authors"> <span class="search-hit">Authors:</span> <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=Folatelli%2C+G">G. Folatelli</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=Hamuy%2C+M">M. Hamuy</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=Hsiao%2C+E+Y">E. Y. Hsiao</a>, <a href="/search/astro-ph?searchtype=author&query=Taddia%2C+F">F. Taddia</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=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=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=Lu%2C+J">J. Lu</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=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=Burrow%2C+A">A. Burrow</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=Diamond%2C+T">T. Diamond</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=Gonz%C3%A1lez%2C+C">C. Gonz谩lez</a> , et al. (35 additional authors not shown) </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2404.19208v2-abstract-short" style="display: inline;"> We present the second and final release of optical spectroscopy of Type Ia Supernovae (SNe Ia) obtained during the first and second phases of the Carnegie Supernova Project (CSP-I and CSP-II). The newly released data consist of 148 spectra of 30 SNe Ia observed in the course of the CSP-I, and 234 spectra of 127 SNe Ia obtained during the CSP-II. We also present 216 optical spectra of 46 historical… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2404.19208v2-abstract-full').style.display = 'inline'; document.getElementById('2404.19208v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2404.19208v2-abstract-full" style="display: none;"> We present the second and final release of optical spectroscopy of Type Ia Supernovae (SNe Ia) obtained during the first and second phases of the Carnegie Supernova Project (CSP-I and CSP-II). The newly released data consist of 148 spectra of 30 SNe Ia observed in the course of the CSP-I, and 234 spectra of 127 SNe Ia obtained during the CSP-II. We also present 216 optical spectra of 46 historical SNe Ia, including 53 spectra of 30 SNe Ia observed by the Cal谩n/Tololo Supernova Survey. We combine these observations with previously published CSP data and publicly-available spectra to compile a large sample of measurements of spectroscopic parameters at maximum light, consisting of pseudo-equivalent widths and expansion velocities of selected features, for 232 CSP and historical SNe Ia (including more than 1000 spectra). Finally, we review some of the strongest correlations between spectroscopic and photometric properties of SNe Ia. Specifically, we define two samples: one consisting of SNe Ia discovered by targeted searches (most of them CSP-I objects) and the other composed of SNe Ia discovered by untargeted searches, which includes most of the CSP-II objects. The analysed correlations are similar for both samples. We find a larger incidence of SNe Ia belonging to the Cool (CL)and Broad Line (BL) Branch subtypes among the events discovered by targeted searches, Shallow Silicon (SS) SNe Ia are present with similar frequencies in both samples, while Core Normal (CN) SNe Ia are more frequent in untargeted searches. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2404.19208v2-abstract-full').style.display = 'none'; document.getElementById('2404.19208v2-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, 2024; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 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">59 pages, 16 figures, accepted for publication in The Astrophysical Journal. May 7, 2024: LaTex file updated: corrected one missing comma and an extraneous space in Table 2</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2404.17043">arXiv:2404.17043</a> <span> [<a href="https://arxiv.org/pdf/2404.17043">pdf</a>, <a href="https://arxiv.org/format/2404.17043">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="High Energy Astrophysical Phenomena">astro-ph.HE</span> </div> </div> <p class="title is-5 mathjax"> A JWST Medium Resolution MIRI Spectrum and Models of the Type Ia supernova 2021aefx at +415 d </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Ashall%2C+C">C. Ashall</a>, <a href="/search/astro-ph?searchtype=author&query=Hoeflich%2C+P">P. Hoeflich</a>, <a href="/search/astro-ph?searchtype=author&query=Baron%2C+E">E. Baron</a>, <a href="/search/astro-ph?searchtype=author&query=Shahbandeh%2C+M">M. Shahbandeh</a>, <a href="/search/astro-ph?searchtype=author&query=DerKacy%2C+J+M">J. M. DerKacy</a>, <a href="/search/astro-ph?searchtype=author&query=Medler%2C+K">K. Medler</a>, <a href="/search/astro-ph?searchtype=author&query=Shappee%2C+B+J">B. J. Shappee</a>, <a href="/search/astro-ph?searchtype=author&query=Tucker%2C+M+A">M. A. Tucker</a>, <a href="/search/astro-ph?searchtype=author&query=Fereidouni%2C+E">E. Fereidouni</a>, <a href="/search/astro-ph?searchtype=author&query=Mera%2C+T">T. Mera</a>, <a href="/search/astro-ph?searchtype=author&query=Andrews%2C+J">J. Andrews</a>, <a href="/search/astro-ph?searchtype=author&query=Baade%2C+D">D. Baade</a>, <a href="/search/astro-ph?searchtype=author&query=Bostroem%2C+K+A">K. A. Bostroem</a>, <a href="/search/astro-ph?searchtype=author&query=Brown%2C+P+J">P. J. Brown</a>, <a href="/search/astro-ph?searchtype=author&query=Burns%2C+C+R">C. R. Burns</a>, <a href="/search/astro-ph?searchtype=author&query=Burrow%2C+A">A. Burrow</a>, <a href="/search/astro-ph?searchtype=author&query=Cikota%2C+A">A. Cikota</a>, <a href="/search/astro-ph?searchtype=author&query=de+Jaeger%2C+T">T. de Jaeger</a>, <a href="/search/astro-ph?searchtype=author&query=Do%2C+A">A. Do</a>, <a href="/search/astro-ph?searchtype=author&query=Dong%2C+Y">Y. Dong</a>, <a href="/search/astro-ph?searchtype=author&query=Dominguez%2C+I">I. Dominguez</a>, <a href="/search/astro-ph?searchtype=author&query=Fox%2C+O">O. Fox</a>, <a href="/search/astro-ph?searchtype=author&query=Galbany%2C+L">L. Galbany</a>, <a href="/search/astro-ph?searchtype=author&query=Hsiao%2C+E+Y">E. Y. Hsiao</a>, <a href="/search/astro-ph?searchtype=author&query=Krisciunas%2C+K">K. Krisciunas</a> , et al. (17 additional authors not shown) </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2404.17043v2-abstract-short" style="display: inline;"> We present a JWST MIRI/MRS spectrum (5-27 $\mathrm渭$m) of the Type Ia supernova (SN Ia), SN 2021aefx at $+415$ days past $B$-band maximum. The spectrum, which was obtained during the iron-dominated nebular phase, has been analyzed in combination with previous JWST observations of SN 2021aefx, to provide the first JWST time series analysis of an SN Ia. We find the temporal evolution of the [Co III]… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2404.17043v2-abstract-full').style.display = 'inline'; document.getElementById('2404.17043v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2404.17043v2-abstract-full" style="display: none;"> We present a JWST MIRI/MRS spectrum (5-27 $\mathrm渭$m) of the Type Ia supernova (SN Ia), SN 2021aefx at $+415$ days past $B$-band maximum. The spectrum, which was obtained during the iron-dominated nebular phase, has been analyzed in combination with previous JWST observations of SN 2021aefx, to provide the first JWST time series analysis of an SN Ia. We find the temporal evolution of the [Co III] 11.888 $\mathrm渭$m feature directly traces the decay of $^{56}$Co. The spectra, line profiles, and their evolution are analyzed with off-center delayed-detonation models. Best fits were obtained with White Dwarf (WD) central densities of $蟻_c=0.9-1.1\times 10^9$g cm$^{-3}$, a WD mass of M$_{\mathrm{WD}}$=1.33-1.35M$_\odot$, a WD magnetic field of $\approx10^6$G, and an off-center deflagration-to-detonation transition at $\approx$ 0.5 $M_\odot$ seen opposite to the line of sight of the observer (-30). The inner electron capture core is dominated by energy deposition from $纬$-rays whereas a broader region is dominated by positron deposition, placing SN 2021aefx at +415 d in the transitional phase of the evolution to the positron-dominated regime. The formerly `flat-tilted' profile at 9 $\mathrm渭$m now has significant contribution from [Ni IV], [Fe II], and [Fe III] and less from [Ar III], which alters the shape of the feature as positrons excite mostly the low-velocity Ar. Overall, the strength of the stable Ni features in the spectrum is dominated by positron transport rather than the Ni mass. Based on multi-dimensional models, our analysis is consistent with a single-spot, close-to-central ignition with an indication for a pre-existing turbulent velocity field, and excludes a multiple-spot, off-center ignition. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2404.17043v2-abstract-full').style.display = 'none'; document.getElementById('2404.17043v2-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 2 July, 2024; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 25 April, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> April 2024. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">Accepted for publication in ApJ</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2404.04724">arXiv:2404.04724</a> <span> [<a href="https://arxiv.org/pdf/2404.04724">pdf</a>, <a href="https://arxiv.org/format/2404.04724">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"> Extrapolation of Type Ia Supernova Spectra into the Near-Infrared Using PCA </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Burrow%2C+A">Anthony Burrow</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">Christopher R. Burns</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=Lu%2C+J">Jing Lu</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+J">Peter J. Brown</a>, <a href="/search/astro-ph?searchtype=author&query=DerKacy%2C+J+M">James M. DerKacy</a>, <a href="/search/astro-ph?searchtype=author&query=Folatelli%2C+G">G. Folatelli</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=Hoeflich%2C+P">P. Hoeflich</a>, <a href="/search/astro-ph?searchtype=author&query=Krisciunas%2C+K">Kevin Krisciunas</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=Shappee%2C+B+J">Benjamin J. Shappee</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> </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="2404.04724v1-abstract-short" style="display: inline;"> We present a method of extrapolating the spectroscopic behavior of Type Ia supernovae (SNe Ia) in the near-infrared (NIR) wavelength regime up to 2.30 $渭$m using optical spectroscopy. Such a process is useful for accurately estimating K-corrections and other photometric quantities of SNe Ia in the NIR. Principal component analysis is performed on data consisting of Carnegie Supernova Project I & I… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2404.04724v1-abstract-full').style.display = 'inline'; document.getElementById('2404.04724v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2404.04724v1-abstract-full" style="display: none;"> We present a method of extrapolating the spectroscopic behavior of Type Ia supernovae (SNe Ia) in the near-infrared (NIR) wavelength regime up to 2.30 $渭$m using optical spectroscopy. Such a process is useful for accurately estimating K-corrections and other photometric quantities of SNe Ia in the NIR. Principal component analysis is performed on data consisting of Carnegie Supernova Project I & II optical and near-infrared FIRE spectra to produce models capable of making these extrapolations. This method differs from previous spectral template methods by not parameterizing models strictly by photometric light-curve properties of SNe Ia, allowing for more flexibility of the resulting extrapolated NIR flux. A difference of around -3.1% to -2.7% in the total integrated NIR flux between these extrapolations and the observations is seen here for most test cases including Branch core-normal and shallow-silicon subtypes. However, larger deviations from the observation are found for other tests, likely due to the limited high-velocity and broad-line SNe Ia in the training sample. Maximum-light principal components are shown to allow for spectroscopic predictions of the color-stretch light-curve parameter, $s_{BV}$, within approximately $\pm$0.1 units of the value measured with photometry. We also show these results compare well with NIR templates, although in most cases the templates are marginally more fitting to observations, illustrating a need for more concurrent optical+NIR spectroscopic observations to truly understand the diversity of SNe Ia in the NIR. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2404.04724v1-abstract-full').style.display = 'none'; document.getElementById('2404.04724v1-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 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">25 pages, 16 figures, ApJ, in press</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2401.14474">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/2311.03473">arXiv:2311.03473</a> <span> [<a href="https://arxiv.org/pdf/2311.03473">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> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Cosmology and Nongalactic Astrophysics">astro-ph.CO</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/ad4702">10.3847/1538-4357/ad4702 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Type Ia Supernova Progenitor Properties and Their Host Galaxies </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Chakraborty%2C+S">Sudeshna Chakraborty</a>, <a href="/search/astro-ph?searchtype=author&query=Sadler%2C+B">Benjamin Sadler</a>, <a href="/search/astro-ph?searchtype=author&query=Hoeflich%2C+P">Peter Hoeflich</a>, <a href="/search/astro-ph?searchtype=author&query=Hsiao%2C+E">Eric 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=Burns%2C+C+R">C. R. Burns</a>, <a href="/search/astro-ph?searchtype=author&query=Diamond%2C+T">T. Diamond</a>, <a href="/search/astro-ph?searchtype=author&query=Dominguez%2C+I">I. Dominguez</a>, <a href="/search/astro-ph?searchtype=author&query=Galbany%2C+L">L. Galbany</a>, <a href="/search/astro-ph?searchtype=author&query=Uddin%2C+S+A">S. A. Uddin</a>, <a href="/search/astro-ph?searchtype=author&query=Ashall%2C+C">C. Ashall</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=Mera%2C+T+B">T. B. Mera</a>, <a href="/search/astro-ph?searchtype=author&query=Morrell%2C+N">N. Morrell</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+M+C">M. C. Contreras</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+N">N. N. Suntzeff</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="2311.03473v3-abstract-short" style="display: inline;"> We present an eigenfunction method to analyze 161 visual light curves (LCs) of Type Ia supernovae (SNe Ia) obtained by the Carnegie Supernova Project to characterize their diversity and host-galaxy correlations. The eigenfunctions are based on the delayed-detonation scenario using three parameters: the LC stretch being determined by the amount of deflagration-burning governing the 56Ni production,… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2311.03473v3-abstract-full').style.display = 'inline'; document.getElementById('2311.03473v3-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2311.03473v3-abstract-full" style="display: none;"> We present an eigenfunction method to analyze 161 visual light curves (LCs) of Type Ia supernovae (SNe Ia) obtained by the Carnegie Supernova Project to characterize their diversity and host-galaxy correlations. The eigenfunctions are based on the delayed-detonation scenario using three parameters: the LC stretch being determined by the amount of deflagration-burning governing the 56Ni production, the main-sequence mass M_MS of the progenitor white dwarf controlling the explosion energy, and its central density rho_c shifting the 56Ni distribution. Our analysis tool (SPAT) extracts the parameters from observations and projects them into physical space using their allowed ranges M_MS < 8 M_sun, rho_c < 7-8x10^9g/cc. The residuals between fits and individual LC-points are ~ 1-3% for ~ 92% of objects. We find two distinct M_MS groups corresponding to a fast (~ 40-65 Myrs) and a slow(~ 200-500 Myrs) stellar evolution. Most underluminous SNe Ia have hosts with low star formation but high M_MS, suggesting slow evolution times of the progenitor system. 91T-likes SNe show very similar LCs and high M_MS and are correlated to star formation regions, making them potentially important tracers of star formation in the early Universe out to z = 4-11. Some 6% outliers with `non-physical' parameters can be attributed to superluminous SNe Ia and subluminous SNe Ia with hosts of active star formation. For deciphering the SNe Ia diversity and high-precision SNe Ia cosmology, the importance is shown for LCs covering out to ~ 60 days past maximum. Finally, our method and results are discussed within the framework of multiple explosion scenarios, and in light of upcoming surveys. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2311.03473v3-abstract-full').style.display = 'none'; document.getElementById('2311.03473v3-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 July, 2024; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 6 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">42 pages, 22 figures, 6 tables in main text, 2 tables in appendix. This work has been published in the ApJ journal and is in partial fulfillment of the PhD thesis of the first author</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> The Astrophysical Journal (2024), Volume 969, Number 2, 80 </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2310.09153">arXiv:2310.09153</a> <span> [<a href="https://arxiv.org/pdf/2310.09153">pdf</a>, <a href="https://arxiv.org/format/2310.09153">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="High Energy Astrophysical Phenomena">astro-ph.HE</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> </div> </div> <p class="title is-5 mathjax"> JWST MIRI/MRS Observations and Spectral Models of the Under-luminous Type Ia Supernova 2022xkq </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=DerKacy%2C+J+M">J. M. DerKacy</a>, <a href="/search/astro-ph?searchtype=author&query=Ashall%2C+C">C. Ashall</a>, <a href="/search/astro-ph?searchtype=author&query=Hoeflich%2C+P">P. Hoeflich</a>, <a href="/search/astro-ph?searchtype=author&query=Baron%2C+E">E. Baron</a>, <a href="/search/astro-ph?searchtype=author&query=Shahbandeh%2C+M">M. Shahbandeh</a>, <a href="/search/astro-ph?searchtype=author&query=Shappee%2C+B+J">B. J. Shappee</a>, <a href="/search/astro-ph?searchtype=author&query=Andrews%2C+J">J. Andrews</a>, <a href="/search/astro-ph?searchtype=author&query=Baade%2C+D">D. Baade</a>, <a href="/search/astro-ph?searchtype=author&query=Balangan%2C+E+F">E. F Balangan</a>, <a href="/search/astro-ph?searchtype=author&query=Bostroem%2C+K+A">K. A. Bostroem</a>, <a href="/search/astro-ph?searchtype=author&query=Brown%2C+P+J">P. J. Brown</a>, <a href="/search/astro-ph?searchtype=author&query=Burns%2C+C+R">C. R. Burns</a>, <a href="/search/astro-ph?searchtype=author&query=Burrow%2C+A">A. Burrow</a>, <a href="/search/astro-ph?searchtype=author&query=Cikota%2C+A">A. Cikota</a>, <a href="/search/astro-ph?searchtype=author&query=de+Jaeger%2C+T">T. de Jaeger</a>, <a href="/search/astro-ph?searchtype=author&query=Do%2C+A">A. Do</a>, <a href="/search/astro-ph?searchtype=author&query=Dong%2C+Y">Y. Dong</a>, <a href="/search/astro-ph?searchtype=author&query=Dominguez%2C+I">I. Dominguez</a>, <a href="/search/astro-ph?searchtype=author&query=Fox%2C+O">O. Fox</a>, <a href="/search/astro-ph?searchtype=author&query=Galbany%2C+L">L. Galbany</a>, <a href="/search/astro-ph?searchtype=author&query=Hoang%2C+E+T">E. T. Hoang</a>, <a href="/search/astro-ph?searchtype=author&query=Hsiao%2C+E+Y">E. Y. Hsiao</a>, <a href="/search/astro-ph?searchtype=author&query=Janzen%2C+D">D. Janzen</a>, <a href="/search/astro-ph?searchtype=author&query=Jencson%2C+J+E">J. E. Jencson</a>, <a href="/search/astro-ph?searchtype=author&query=Krisciunas%2C+K">K. Krisciunas</a> , et al. (22 additional authors not shown) </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2310.09153v2-abstract-short" style="display: inline;"> We present a JWST mid-infrared spectrum of the under-luminous Type Ia Supernova (SN Ia) 2022xkq, obtained with the medium-resolution spectrometer on the Mid-Infrared Instrument (MIRI) $\sim130$ days post-explosion. We identify the first MIR lines beyond 14 $渭$m in SN Ia observations. We find features unique to under-luminous SNe Ia, including: isolated emission of stable Ni, strong blends of [Ti I… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2310.09153v2-abstract-full').style.display = 'inline'; document.getElementById('2310.09153v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2310.09153v2-abstract-full" style="display: none;"> We present a JWST mid-infrared spectrum of the under-luminous Type Ia Supernova (SN Ia) 2022xkq, obtained with the medium-resolution spectrometer on the Mid-Infrared Instrument (MIRI) $\sim130$ days post-explosion. We identify the first MIR lines beyond 14 $渭$m in SN Ia observations. We find features unique to under-luminous SNe Ia, including: isolated emission of stable Ni, strong blends of [Ti II], and large ratios of singly ionized to doubly ionized species in both [Ar] and [Co]. Comparisons to normal-luminosity SNe Ia spectra at similar phases show a tentative trend between the width of the [Co III] 11.888 $渭$m feature and the SN light curve shape. Using non-LTE-multi-dimensional radiation hydro simulations and the observed electron capture elements we constrain the mass of the exploding white dwarf. The best-fitting model shows that SN 2022xkq is consistent with an off-center delayed-detonation explosion of a near-Chandrasekhar mass WD (M$_{\rm ej}$ $\approx 1.37$ M$_{\odot}$) of high-central density ($蟻_c \geq 2.0\times10^{9}$ g cm$^{-3}$) seen equator on, which produced M($^{56}$Ni) $= 0.324$ M$_{\odot}$ and M($^{58}$Ni) $\geq 0.06$ M$_{\odot}$. The observed line widths are consistent with the overall abundance distribution; and the narrow stable Ni lines indicate little to no mixing in the central regions, favoring central ignition of sub-sonic carbon burning followed by an off-center DDT beginning at a single point. Additional observations may further constrain the physics revealing the presence of additional species including Cr and Mn. Our work demonstrates the power of using the full coverage of MIRI in combination with detailed modeling to elucidate the physics of SNe Ia at a level not previously possible. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2310.09153v2-abstract-full').style.display = 'none'; document.getElementById('2310.09153v2-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 7 November, 2023; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 13 October, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> October 2023. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">31 pages, 18 figures, accepted to ApJ; updated to accepted version</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/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/2301.03647">arXiv:2301.03647</a> <span> [<a href="https://arxiv.org/pdf/2301.03647">pdf</a>, <a href="https://arxiv.org/format/2301.03647">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="High Energy Astrophysical Phenomena">astro-ph.HE</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.3847/2041-8213/acb8a8">10.3847/2041-8213/acb8a8 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> JWST Low-Resolution MIRI Spectral Observations of SN~2021aefx: High-density Burning in a Type Ia Supernova </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=DerKacy%2C+J+M">J. M. DerKacy</a>, <a href="/search/astro-ph?searchtype=author&query=Ashall%2C+C">C. Ashall</a>, <a href="/search/astro-ph?searchtype=author&query=Hoeflich%2C+P">P. Hoeflich</a>, <a href="/search/astro-ph?searchtype=author&query=Baron%2C+E">E. Baron</a>, <a href="/search/astro-ph?searchtype=author&query=Shappee%2C+B+J">B. J. Shappee</a>, <a href="/search/astro-ph?searchtype=author&query=Baade%2C+D">D. Baade</a>, <a href="/search/astro-ph?searchtype=author&query=Andrews%2C+J">J. Andrews</a>, <a href="/search/astro-ph?searchtype=author&query=Bostroem%2C+K+A">K. A. Bostroem</a>, <a href="/search/astro-ph?searchtype=author&query=Brown%2C+P+J">P. J. Brown</a>, <a href="/search/astro-ph?searchtype=author&query=Burns%2C+C+R">C. R. Burns</a>, <a href="/search/astro-ph?searchtype=author&query=Burrow%2C+A">A. Burrow</a>, <a href="/search/astro-ph?searchtype=author&query=Cikota%2C+A">A. Cikota</a>, <a href="/search/astro-ph?searchtype=author&query=de+Jaeger%2C+T">T. de Jaeger</a>, <a href="/search/astro-ph?searchtype=author&query=Do%2C+A">A. Do</a>, <a href="/search/astro-ph?searchtype=author&query=Dong%2C+Y">Y. Dong</a>, <a href="/search/astro-ph?searchtype=author&query=Dominguez%2C+I">I. Dominguez</a>, <a href="/search/astro-ph?searchtype=author&query=Galbany%2C+L">L. Galbany</a>, <a href="/search/astro-ph?searchtype=author&query=Hsiao%2C+E+Y">E. Y. Hsiao</a>, <a href="/search/astro-ph?searchtype=author&query=Karamehmetoglu%2C+E">E. Karamehmetoglu</a>, <a href="/search/astro-ph?searchtype=author&query=Krisciunas%2C+K">K. Krisciunas</a>, <a href="/search/astro-ph?searchtype=author&query=Kumar%2C+S">S. Kumar</a>, <a href="/search/astro-ph?searchtype=author&query=Lu%2C+J">J. Lu</a>, <a href="/search/astro-ph?searchtype=author&query=Evans%2C+T+B+M">T. B. Mera Evans</a>, <a href="/search/astro-ph?searchtype=author&query=Maund%2C+J+R">J. R. Maund</a>, <a href="/search/astro-ph?searchtype=author&query=Mazzali%2C+P">P. Mazzali</a> , et al. (16 additional authors not shown) </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2301.03647v2-abstract-short" style="display: inline;"> We present a JWST/MIRI low-resolution mid-infrared (MIR) spectroscopic observation of the normal Type Ia supernova (SN Ia) SN 2021aefx at +323 days past rest-frame B-band maximum light. The spectrum ranges from 4-14 um, and shows many unique qualities including a flat-topped [Ar III] 8.991 um profile, a strongly tilted [Co III] 11.888 um feature, and multiple stable Ni lines. These features provid… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2301.03647v2-abstract-full').style.display = 'inline'; document.getElementById('2301.03647v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2301.03647v2-abstract-full" style="display: none;"> We present a JWST/MIRI low-resolution mid-infrared (MIR) spectroscopic observation of the normal Type Ia supernova (SN Ia) SN 2021aefx at +323 days past rest-frame B-band maximum light. The spectrum ranges from 4-14 um, and shows many unique qualities including a flat-topped [Ar III] 8.991 um profile, a strongly tilted [Co III] 11.888 um feature, and multiple stable Ni lines. These features provide critical information about the physics of the explosion. The observations are compared to synthetic spectra from detailed NLTE multi-dimensional models. The results of the best-fitting model are used to identify the components of the spectral blends and provide a quantitative comparison to the explosion physics. Emission line profiles and the presence of electron capture (EC) elements are used to constrain the mass of the exploding white dwarf (WD) and the chemical asymmetries in the ejecta. We show that the observations of SN 2021aefx are consistent with an off-center delayed-detonation explosion of a near-Chandrasekhar mass (Mch) WD at a viewing angle of -30 degrees relative to the point of the deflagration-to-detonation transition. From the strength of the stable Ni lines we determine that there is little to no mixing in the central regions of the ejecta. Based on both the presence of stable Ni and the Ar velocity distributions, we obtain a strict lower limit of 1.2 Msun of the initial WD, implying that most sub-Mch explosions models are not viable models for SN 2021aefx. The analysis here shows the crucial importance of MIR spectra for distinguishing between explosion scenarios for SNe Ia. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2301.03647v2-abstract-full').style.display = 'none'; document.getElementById('2301.03647v2-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 2 February, 2023; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 9 January, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> January 2023. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">21 pages, 9 figures, 4 tables, accepted to ApJL; updated to accepted version</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2212.06195">arXiv:2212.06195</a> <span> [<a href="https://arxiv.org/pdf/2212.06195">pdf</a>, <a href="https://arxiv.org/format/2212.06195">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/stad1171">10.1093/mnras/stad1171 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> SN 2021fxy: Mid-Ultraviolet Flux Suppression is a Common Feature of Type Ia Supernovae </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=DerKacy%2C+J+M">J. M. DerKacy</a>, <a href="/search/astro-ph?searchtype=author&query=Paugh%2C+S">S. Paugh</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=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=Hsiao%2C+E+Y">E. Y. Hsiao</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=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=Shahbandeh%2C+M">M. Shahbandeh</a>, <a href="/search/astro-ph?searchtype=author&query=Shappee%2C+B+J">B. J. Shappee</a>, <a href="/search/astro-ph?searchtype=author&query=Stritzinger%2C+M+D">M. D. Stritzinger</a>, <a href="/search/astro-ph?searchtype=author&query=Tucker%2C+M+A">M. A. Tucker</a>, <a href="/search/astro-ph?searchtype=author&query=Yarbrough%2C+Z">Z. Yarbrough</a>, <a href="/search/astro-ph?searchtype=author&query=Boutsia%2C+K">K. Boutsia</a>, <a href="/search/astro-ph?searchtype=author&query=Hoeflich%2C+P">P. Hoeflich</a>, <a href="/search/astro-ph?searchtype=author&query=Wang%2C+L">L. Wang</a>, <a href="/search/astro-ph?searchtype=author&query=Galbany%2C+L">L. Galbany</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=Mazzali%2C+P">P. Mazzali</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=Suntzeff%2C+N+B">N. B. Suntzeff</a> , et al. (4 additional authors not shown) </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2212.06195v1-abstract-short" style="display: inline;"> We present ultraviolet (UV) to near-infrared (NIR) observations and analysis of the nearby Type Ia supernova SN 2021fxy. Our observations include UV photometry from Swift/UVOT, UV spectroscopy from HST/STIS, and high-cadence optical photometry with the Swope 1-m telescope capturing intra-night rises during the early light curve. Early $B-V$ colours show SN 2021fxy is the first "shallow-silicon" (S… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2212.06195v1-abstract-full').style.display = 'inline'; document.getElementById('2212.06195v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2212.06195v1-abstract-full" style="display: none;"> We present ultraviolet (UV) to near-infrared (NIR) observations and analysis of the nearby Type Ia supernova SN 2021fxy. Our observations include UV photometry from Swift/UVOT, UV spectroscopy from HST/STIS, and high-cadence optical photometry with the Swope 1-m telescope capturing intra-night rises during the early light curve. Early $B-V$ colours show SN 2021fxy is the first "shallow-silicon" (SS) SN Ia to follow a red-to-blue evolution, compared to other SS objects which show blue colours from the earliest observations. Comparisons to other spectroscopically normal SNe Ia with HST UV spectra reveal SN 2021fxy is one of several SNe Ia with flux suppression in the mid-UV. These SNe also show blue-shifted mid-UV spectral features and strong high-velocity Ca II features. One possible origin of this mid-UV suppression is the increased effective opacity in the UV due to increased line blanketing from high velocity material, but differences in the explosion mechanism cannot be ruled out. Among SNe Ia with mid-UV suppression, SNe 2021fxy and 2017erp show substantial similarities in their optical properties despite belonging to different Branch subgroups, and UV flux differences of the same order as those found between SNe 2011fe and 2011by. Differential comparisons to multiple sets of synthetic SN Ia UV spectra reveal this UV flux difference likely originates from a luminosity difference between SNe 2021fxy and 2017erp, and not differing progenitor metallicities as suggested for SNe 2011by and 2011fe. These comparisons illustrate the complicated nature of UV spectral formation, and the need for more UV spectra to determine the physical source of SNe Ia UV diversity. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2212.06195v1-abstract-full').style.display = 'none'; document.getElementById('2212.06195v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 12 December, 2022; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> December 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">26 pages, 19 figures, 9 tables; submitted to MNRAS, posted after receiving referee comments</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/2211.00038">arXiv:2211.00038</a> <span> [<a href="https://arxiv.org/pdf/2211.00038">pdf</a>, <a href="https://arxiv.org/format/2211.00038">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/acb4ec">10.3847/2041-8213/acb4ec <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> A JWST Near- and Mid-Infrared Nebular Spectrum of the Type Ia Supernova 2021aefx </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Kwok%2C+L+A">Lindsey A. Kwok</a>, <a href="/search/astro-ph?searchtype=author&query=Jha%2C+S+W">Saurabh W. Jha</a>, <a href="/search/astro-ph?searchtype=author&query=Temim%2C+T">Tea Temim</a>, <a href="/search/astro-ph?searchtype=author&query=Fox%2C+O+D">Ori D. Fox</a>, <a href="/search/astro-ph?searchtype=author&query=Larison%2C+C">Conor Larison</a>, <a href="/search/astro-ph?searchtype=author&query=Camacho-Neves%2C+Y">Yssavo Camacho-Neves</a>, <a href="/search/astro-ph?searchtype=author&query=Newman%2C+M+J+B">Max J. Brenner Newman</a>, <a href="/search/astro-ph?searchtype=author&query=Pierel%2C+J+D+R">Justin D. R. Pierel</a>, <a href="/search/astro-ph?searchtype=author&query=Foley%2C+R+J">Ryan J. Foley</a>, <a href="/search/astro-ph?searchtype=author&query=Andrews%2C+J+E">Jennifer E. Andrews</a>, <a href="/search/astro-ph?searchtype=author&query=Badenes%2C+C">Carles Badenes</a>, <a href="/search/astro-ph?searchtype=author&query=Barna%2C+B">Barnabas Barna</a>, <a href="/search/astro-ph?searchtype=author&query=Bostroem%2C+K+A">K. Azalee Bostroem</a>, <a href="/search/astro-ph?searchtype=author&query=Deckers%2C+M">Maxime Deckers</a>, <a href="/search/astro-ph?searchtype=author&query=Flors%2C+A">Andreas Flors</a>, <a href="/search/astro-ph?searchtype=author&query=Garnavich%2C+P">Peter Garnavich</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=Graur%2C+O">Or Graur</a>, <a href="/search/astro-ph?searchtype=author&query=Hosseinzadeh%2C+G">Griffin Hosseinzadeh</a>, <a href="/search/astro-ph?searchtype=author&query=Howell%2C+D+A">D. Andrew Howell</a>, <a href="/search/astro-ph?searchtype=author&query=Hughes%2C+J+P">John P. Hughes</a>, <a href="/search/astro-ph?searchtype=author&query=Johansson%2C+J">Joel Johansson</a>, <a href="/search/astro-ph?searchtype=author&query=Kendrew%2C+S">Sarah Kendrew</a>, <a href="/search/astro-ph?searchtype=author&query=Kerzendorf%2C+W+E">Wolfgang E. Kerzendorf</a>, <a href="/search/astro-ph?searchtype=author&query=Maeda%2C+K">Keiichi Maeda</a> , et al. (33 additional authors not shown) </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2211.00038v2-abstract-short" style="display: inline;"> We present JWST near- and mid-infrared spectroscopic observations of the nearby normal Type Ia supernova SN 2021aefx in the nebular phase at $+255$ days past maximum light. Our Near Infrared Spectrograph (NIRSpec) and Mid Infrared Instrument (MIRI) observations, combined with ground-based optical data from the South African Large Telescope (SALT), constitute the first complete optical $+$ NIR $+$… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2211.00038v2-abstract-full').style.display = 'inline'; document.getElementById('2211.00038v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2211.00038v2-abstract-full" style="display: none;"> We present JWST near- and mid-infrared spectroscopic observations of the nearby normal Type Ia supernova SN 2021aefx in the nebular phase at $+255$ days past maximum light. Our Near Infrared Spectrograph (NIRSpec) and Mid Infrared Instrument (MIRI) observations, combined with ground-based optical data from the South African Large Telescope (SALT), constitute the first complete optical $+$ NIR $+$ MIR nebular SN Ia spectrum covering 0.3$-$14 $渭$m. This spectrum unveils the previously unobserved 2.5$-$5 $渭$m region, revealing strong nebular iron and stable nickel emission, indicative of high-density burning that can constrain the progenitor mass. The data show a significant improvement in sensitivity and resolution compared to previous Spitzer MIR data. We identify numerous NIR and MIR nebular emission lines from iron-group elements and as well as lines from the intermediate-mass element argon. The argon lines extend to higher velocities than the iron-group elements, suggesting stratified ejecta that are a hallmark of delayed-detonation or double-detonation SN Ia models. We present fits to simple geometric line profiles to features beyond 1.2 $渭$m and find that most lines are consistent with Gaussian or spherical emission distributions, while the [Ar III] 8.99 $渭$m line has a distinctively flat-topped profile indicating a thick spherical shell of emission. Using our line profile fits, we investigate the emissivity structure of SN 2021aefx and measure kinematic properties. Continued observations of SN 2021aefx and other SNe Ia with JWST will be transformative to the study of SN Ia composition, ionization structure, density, and temperature, and will provide important constraints on SN Ia progenitor and explosion models. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2211.00038v2-abstract-full').style.display = 'none'; document.getElementById('2211.00038v2-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 February, 2023; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 31 October, 2022; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> November 2022. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">published in ApJ Letters, 17 pages, 12 figures</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> ApJL, Volume 944 L3, 2023 </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/2209.08031">arXiv:2209.08031</a> <span> [<a href="https://arxiv.org/pdf/2209.08031">pdf</a>, <a href="https://arxiv.org/ps/2209.08031">ps</a>, <a href="https://arxiv.org/format/2209.08031">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/ac9305">10.3847/1538-4357/ac9305 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> The Absolute Magnitudes of 1991T-like Supernovae </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Phillips%2C+M+M">M. M. Phillips</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">Christopher R. Burns</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">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=Hsiao%2C+E+Y">E. Y. Hsiao</a>, <a href="/search/astro-ph?searchtype=author&query=Morrell%2C+N">Nidia Morrell</a>, <a href="/search/astro-ph?searchtype=author&query=Nugent%2C+P">Peter Nugent</a>, <a href="/search/astro-ph?searchtype=author&query=Uddin%2C+S+A">Syed A. Uddin</a>, <a href="/search/astro-ph?searchtype=author&query=Baron%2C+E">E. Baron</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=Harris%2C+C+E">Chelsea E. Harris</a>, <a href="/search/astro-ph?searchtype=author&query=Krisciunas%2C+K">Kevin 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=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=Polin%2C+A">Abigail Polin</a>, <a href="/search/astro-ph?searchtype=author&query=Shahbandeh"> Shahbandeh</a>, <a href="/search/astro-ph?searchtype=author&query=M."> M.</a>, <a href="/search/astro-ph?searchtype=author&query=Stritzinger%2C+M">Maximilian Stritzinger</a>, <a href="/search/astro-ph?searchtype=author&query=Suntzeff%2C+N+B">Nicholas B. Suntzeff</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="2209.08031v1-abstract-short" style="display: inline;"> 1991T-like supernovae are the luminous, slow-declining extreme of the Branch shallow-silicon (SS) subclass of Type Ia supernovae. They are distinguished by extremely weak Ca II H & K and Si II $\lambda6355$ and strong Fe III absorption features in their optical spectra at pre-maximum phases, and have long been suspected to be over-luminous compared to normal Type Ia supernovae. In this paper, the… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2209.08031v1-abstract-full').style.display = 'inline'; document.getElementById('2209.08031v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2209.08031v1-abstract-full" style="display: none;"> 1991T-like supernovae are the luminous, slow-declining extreme of the Branch shallow-silicon (SS) subclass of Type Ia supernovae. They are distinguished by extremely weak Ca II H & K and Si II $\lambda6355$ and strong Fe III absorption features in their optical spectra at pre-maximum phases, and have long been suspected to be over-luminous compared to normal Type Ia supernovae. In this paper, the pseudo equivalent width of the Si II $位$6355 absorption obtained at light curve phases from $\leq+10$ days is combined with the morphology of the $i$-band light curve to identify a sample of 1991T-like supernovae in the Carnegie Supernova Project-II. Hubble diagram residuals show that, at optical as well as near-infrared wavelengths, these events are over-luminous by $\sim$0.1-0.5 mag with respect to the less extreme Branch SS (1999aa-like) and Branch core-normal supernovae with similar $B$-band light curve decline rates. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2209.08031v1-abstract-full').style.display = 'none'; document.getElementById('2209.08031v1-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 September, 2022; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> September 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 (Aug 30, 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/2209.06301">arXiv:2209.06301</a> <span> [<a href="https://arxiv.org/pdf/2209.06301">pdf</a>, <a href="https://arxiv.org/format/2209.06301">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/ac8c97">10.3847/1538-4357/ac8c97 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Using 1991T/1999aa-like Type Ia Supernovae as Standardizable Candles </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Yang%2C+J">Jiawen Yang</a>, <a href="/search/astro-ph?searchtype=author&query=Wang%2C+L">Lifan Wang</a>, <a href="/search/astro-ph?searchtype=author&query=Suntzeff%2C+N">Nicholas Suntzeff</a>, <a href="/search/astro-ph?searchtype=author&query=Hu%2C+L">Lei Hu</a>, <a href="/search/astro-ph?searchtype=author&query=Aldoroty%2C+L">Lauren Aldoroty</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=Krisciunas%2C+K">Kevin Krisciunas</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=Galbany%2C+L">Llu铆s Galbany</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>, <a href="/search/astro-ph?searchtype=author&query=McCully%2C+C">Curtis McCully</a>, <a href="/search/astro-ph?searchtype=author&query=Pellegrino%2C+C">Craig Pellegrino</a>, <a href="/search/astro-ph?searchtype=author&query=Valenti%2C+S">Stefano Valenti</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="2209.06301v1-abstract-short" style="display: inline;"> We present the photometry of 16 91T/99aa-like Type Ia Supernovae (SNe Ia) observed by the Las Cumbres Observatory. We also use an additional set of 21 91T/99aa-like SNe Ia and 87 normal SNe Ia from the literature for an analysis of the standardizability of the luminosity of 91T/99aa-like SNe. We find that 91T/99aa-like SNe are 0.2 mag brighter than normal SNe Ia, even when fully corrected by the l… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2209.06301v1-abstract-full').style.display = 'inline'; document.getElementById('2209.06301v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2209.06301v1-abstract-full" style="display: none;"> We present the photometry of 16 91T/99aa-like Type Ia Supernovae (SNe Ia) observed by the Las Cumbres Observatory. We also use an additional set of 21 91T/99aa-like SNe Ia and 87 normal SNe Ia from the literature for an analysis of the standardizability of the luminosity of 91T/99aa-like SNe. We find that 91T/99aa-like SNe are 0.2 mag brighter than normal SNe Ia, even when fully corrected by the light curve shapes and colors. The weighted root-mean-square of 91T/99aa-like SNe (with $z_{CMB}>0.01$) Hubble residuals is $0.25\pm0.03$ mag, suggesting that 91T/99aa-like SNe are also excellent relative distance indicators to $\pm$12%. We compare the Hubble residuals with the pseudo-equivalent width (pEW) of Si II $位位$6355 around the date of maximum brightness. We find that there is a broken linear correlation in between those two measurements for our sample including both 91T/99aa-like and normal SNe Ia. As the $pEW_{max}$(Si II $位位$6355) increasing, the Hubble residual increases when $pEW_{max}$(Si II $位位$6355)$<55.6$ 脜. However, the Hubble residual stays constant beyond this. Given that 91T/99aa-like SNe possess shallower Si II lines than normal SNe Ia, the linear correlation at $pEW_{max}$(Si II $位位$6355)$<55.6$ 脜 can account for the overall discrepancy of Hubble residuals derived from the two subgroups. Such a systematic effect needs to be taken into account when using SNe Ia to measure luminosity distances. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2209.06301v1-abstract-full').style.display = 'none'; document.getElementById('2209.06301v1-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, 2022; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> September 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">25 pages, 10 figures, 10 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/2205.00606">arXiv:2205.00606</a> <span> [<a href="https://arxiv.org/pdf/2205.00606">pdf</a>, <a href="https://arxiv.org/format/2205.00606">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/ac7235">10.3847/2041-8213/ac7235 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> A Speed Bump: SN 2021aefx Shows that Doppler Shift Alone can Explain Early-Excess Blue Flux in Some 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=Shappee%2C+B+J">B. J. Shappee</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=Hsiao%2C+E+Y">E. Y. Hsiao</a>, <a href="/search/astro-ph?searchtype=author&query=Kumar%2C+S">S. Kumar</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=Shahbandeh%2C+M">M. Shahbandeh</a>, <a href="/search/astro-ph?searchtype=author&query=Baron%2C+E">E. Baron</a>, <a href="/search/astro-ph?searchtype=author&query=Boutsia%2C+K">K. Boutsia</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=DerKacy%2C+J+M">J. M. DerKacy</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=Krisciunas%2C+K">K. Krisciunas</a>, <a href="/search/astro-ph?searchtype=author&query=Mazzali%2C+P">P. Mazzali</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=Stritzinger%2C+M+D">M. D. Stritzinger</a>, <a href="/search/astro-ph?searchtype=author&query=Suntzeff%2C+N+B">N. B. Suntzeff</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="2205.00606v2-abstract-short" style="display: inline;"> We present early-time photometric and spectroscopic observations of the Type Ia Supernova (SN Ia) 2021aefx. The early time u-band light curve shows an excess flux when compared to normal SNe Ia. We suggest that the early-excess blue flux may be due to a rapid change in spectral velocity in the first few days post explosion, produced by the emission of the Ca II H&K feature passing from the u to th… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2205.00606v2-abstract-full').style.display = 'inline'; document.getElementById('2205.00606v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2205.00606v2-abstract-full" style="display: none;"> We present early-time photometric and spectroscopic observations of the Type Ia Supernova (SN Ia) 2021aefx. The early time u-band light curve shows an excess flux when compared to normal SNe Ia. We suggest that the early-excess blue flux may be due to a rapid change in spectral velocity in the first few days post explosion, produced by the emission of the Ca II H&K feature passing from the u to the B bands on the time scale of a few days. This effect could be dominant for all SNe Ia which have broad absorption features and early-time velocities over 25,000 km/s. It is likely to be one of the main causes of early-excess u-band flux in SNe Ia which have early-time high-velocities. This effect may also be dominant in the UV filters, as well as in places where the SN spectral energy distribution is quickly rising to longer wavelengths. The rapid change in velocity can only produce a monotonic change (in flux-space) in the u-band. For objects which explode at lower velocities, and have a more structured shape in the early-excess emission, there must also be an additional parameter producing the early-time diversity. More early time observations, in particular early spectra, are required to determine how prominent this effect is within SNe Ia. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2205.00606v2-abstract-full').style.display = 'none'; document.getElementById('2205.00606v2-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 23 May, 2022; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 1 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">Accepted for publication in ApJ Letters on 22nd May 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/2201.06066">arXiv:2201.06066</a> <span> [<a href="https://arxiv.org/pdf/2201.06066">pdf</a>, <a href="https://arxiv.org/ps/2201.06066">ps</a>, <a href="https://arxiv.org/format/2201.06066">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/ac4e17">10.3847/1538-4357/ac4e17 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> SN 2012ij: A low-luminosity type Ia supernova and evidence for continuous distribution from 91bg-like explosion to normal ones </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Li%2C+Z">Zhitong Li</a>, <a href="/search/astro-ph?searchtype=author&query=Zhang%2C+T">Tianmeng Zhang</a>, <a href="/search/astro-ph?searchtype=author&query=Wang%2C+X">Xiaofeng Wang</a>, <a href="/search/astro-ph?searchtype=author&query=Sai%2C+H">Hanna Sai</a>, <a href="/search/astro-ph?searchtype=author&query=Zhang%2C+J">Jujia Zhang</a>, <a href="/search/astro-ph?searchtype=author&query=Chen%2C+J">Juncheng Chen</a>, <a href="/search/astro-ph?searchtype=author&query=Zhao%2C+X">Xulin Zhao</a>, <a href="/search/astro-ph?searchtype=author&query=Yan%2C+S">Shengyu Yan</a>, <a href="/search/astro-ph?searchtype=author&query=Wang%2C+B">Bo Wang</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=Hsiao%2C+E+Y">Eric Y. Hsiao</a>, <a href="/search/astro-ph?searchtype=author&query=Morrell%2C+N">Nidia Morrell</a>, <a href="/search/astro-ph?searchtype=author&query=Contreras%2C+C">Carlos Contreras</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">Christopher Ashall</a>, <a href="/search/astro-ph?searchtype=author&query=Stritzinger%2C+M">Maximilian Stritzinger</a>, <a href="/search/astro-ph?searchtype=author&query=Krisciunas%2C+K">Kevin Krisciunas</a>, <a href="/search/astro-ph?searchtype=author&query=Prieto%2C+J">Jose Prieto</a>, <a href="/search/astro-ph?searchtype=author&query=Zou%2C+H">Hu Zou</a>, <a href="/search/astro-ph?searchtype=author&query=Wang%2C+J">Jiali Wang</a>, <a href="/search/astro-ph?searchtype=author&query=Ma%2C+J">Jun Ma</a>, <a href="/search/astro-ph?searchtype=author&query=Nie%2C+J">Jundan Nie</a>, <a href="/search/astro-ph?searchtype=author&query=Xue%2C+S">Suijian Xue</a>, <a href="/search/astro-ph?searchtype=author&query=Zhou%2C+X">Xu Zhou</a>, <a href="/search/astro-ph?searchtype=author&query=Zhou%2C+Z">Zhimin Zhou</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="2201.06066v1-abstract-short" style="display: inline;"> In this paper, we present photometric and spectroscopic observations of a subluminous type Ia supernova (SN Ia) 2012ij, which has an absolute $B$-band peak magnitude $M_{B,\rm{max}}$ = $-$17.95 $\pm$ 0.15 mag. The $B$-band light curve exhibits a fast post-peak decline with $螖m_{15}(B)$ = 1.86 $\pm$ 0.05 mag. All the $R$ and $I$/$i$-band light curves show a weak secondary peak/shoulder feature at a… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2201.06066v1-abstract-full').style.display = 'inline'; document.getElementById('2201.06066v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2201.06066v1-abstract-full" style="display: none;"> In this paper, we present photometric and spectroscopic observations of a subluminous type Ia supernova (SN Ia) 2012ij, which has an absolute $B$-band peak magnitude $M_{B,\rm{max}}$ = $-$17.95 $\pm$ 0.15 mag. The $B$-band light curve exhibits a fast post-peak decline with $螖m_{15}(B)$ = 1.86 $\pm$ 0.05 mag. All the $R$ and $I$/$i$-band light curves show a weak secondary peak/shoulder feature at about 3 weeks after the peak, like some transitional subclass of SNe Ia, which could result from an incomplete merger of near-infrared (NIR) double peaks. The spectra are characterized by Ti~{\sc ii} and strong Si~{\sc ii} $位$5972 absorption features that are usually seen in low-luminosity objects like SN 1999by. The NIR spectrum before maximum light reveals weak carbon absorption features, implying the existence of unburned materials. We compare the observed properties of SN 2012ij with those predicted by the sub-Chandrasekhar-mass and the Chandrasekhar-mass delayed-detonation models, and find that both optical and NIR spectral properties can be explained to some extent by these two models. By comparing the secondary maximum features in $I$ and $i$ bands, we suggest that SN 2012ij is a transitional object linking normal SNe Ia to typical 91bg-like ones. From the published sample of SNe Ia from the $Carnegie~Supernova~Project~II$ (CSP-II), we estimate that the fraction of SN 2012ij-like SNe Ia is not lower than $\sim$ 2%. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2201.06066v1-abstract-full').style.display = 'none'; document.getElementById('2201.06066v1-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 January, 2022; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> January 2022. </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2112.03122">arXiv:2112.03122</a> <span> [<a href="https://arxiv.org/pdf/2112.03122">pdf</a>, <a href="https://arxiv.org/format/2112.03122">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 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/stab3593">10.1093/mnras/stab3593 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Carnegie Supernova Project: kinky $i$-band light-curves of Type Ia 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=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=Anderson%2C+J+P">J. P. Anderson</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=Uddin%2C+S">S. Uddin</a>, <a href="/search/astro-ph?searchtype=author&query=Galbany%2C+L">L. Galbany</a>, <a href="/search/astro-ph?searchtype=author&query=Phiilips%2C+M+M">M. M. Phiilips</a>, <a href="/search/astro-ph?searchtype=author&query=Morrell%2C+N">N. Morrell</a>, <a href="/search/astro-ph?searchtype=author&query=Ashall%2C+C">C. Ashall</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=Hamuy%2C+M">M. Hamuy</a>, <a href="/search/astro-ph?searchtype=author&query=Hoeflich%2C+P">P. Hoeflich</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=Martinez%2C+L">L. Martinez</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=Shahbandeh%2C+M">M. Shahbandeh</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> </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="2112.03122v1-abstract-short" style="display: inline;"> We present detailed investigation of a specific $i$-band light-curve feature in Type Ia supernovae (SNe Ia) using the rapid cadence and high signal-to-noise ratio light-curves obtained by the Carnegie Supernova Project. The feature is present in most SNe Ia and emerges a few days after the $i$-band maximum. It is an abrupt change in curvature in the light-curve over a few days and appears as a fla… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2112.03122v1-abstract-full').style.display = 'inline'; document.getElementById('2112.03122v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2112.03122v1-abstract-full" style="display: none;"> We present detailed investigation of a specific $i$-band light-curve feature in Type Ia supernovae (SNe Ia) using the rapid cadence and high signal-to-noise ratio light-curves obtained by the Carnegie Supernova Project. The feature is present in most SNe Ia and emerges a few days after the $i$-band maximum. It is an abrupt change in curvature in the light-curve over a few days and appears as a flattening in mild cases and a strong downward concave shape, or a "kink", in the most extreme cases. We computed the second derivatives of Gaussian Process interpolations to study 54 rapid-cadence light-curves. From the second derivatives we measure: 1) the timing of the feature in days relative to $i$-band maximum; tdm$_{2}$($i$) and 2) the strength and direction of the concavity in mag d$^{-2}$ ; dm$_{2}$($i$). 76$\%$ of the SNe Ia show a negative dm$_{2}$($i$), representing a downward concavity - either a mild flattening or a strong "kink". The tdm$_{2}$($i$) parameter is shown to correlate with the color-stretch parameter s$_{\mathrm{BV}}$, a SN Ia primary parameter. The dm$_{2}$($i$) parameter shows no correlation with s$_{\mathrm{BV}}$ and therefore provides independent information. It is also largely independent of the spectroscopic and environmental properties. Dividing the sample based on the strength of the light-curve feature as measured by dm$_{2}$($i$), SNe Ia with strong features have a Hubble diagram dispersion of 0.107 mag, 0.075 mag smaller than the group with weak features. Although larger samples should be obtained to test this result, it potentially offers a new method for improving SN Ia distance determinations without shifting to more costly near-infrared or spectroscopic observations. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2112.03122v1-abstract-full').style.display = 'none'; document.getElementById('2112.03122v1-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 December, 2021; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> December 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">15 pages, 13 figures, accepted to be published on 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/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/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/2107.02876">arXiv:2107.02876</a> <span> [<a href="https://arxiv.org/pdf/2107.02876">pdf</a>, <a href="https://arxiv.org/format/2107.02876">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> <p class="title is-5 mathjax"> Including Atmospheric Extinction in a Performance Evaluation of a Fixed Grid of Solar Panels </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Krisciunas%2C+K">Kevin Krisciunas</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="2107.02876v3-abstract-short" style="display: inline;"> We characterize the performance of a fixed grid of solar panels on the basis of data taken under clear sky conditions over 12 months. We confirm that the power output is linearly proportional to cos(theta), where theta is the angular difference of direction toward the Sun and the vector perpendicular to the panels. In order to confirm this we applied methods from astronomical photometry reduction.… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2107.02876v3-abstract-full').style.display = 'inline'; document.getElementById('2107.02876v3-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2107.02876v3-abstract-full" style="display: none;"> We characterize the performance of a fixed grid of solar panels on the basis of data taken under clear sky conditions over 12 months. We confirm that the power output is linearly proportional to cos(theta), where theta is the angular difference of direction toward the Sun and the vector perpendicular to the panels. In order to confirm this we applied methods from astronomical photometry reduction. From late March through August we find that the median effective atmospheric extinction term is 0.145 mag/airmass. From October to mid-March the median extinction term is 0.081 mag/airmass. The proportionality "constant" scaling cos(theta) appears to be seasonally dependent, with the smallest scaling factors occurring when the extinction term is largest. Finally, we find that extinction-corrected power often underperforms the linear relationship late in the morning or early in the afternoon. This is most likely because the efficiency of solar panels depends on their operating temperature, and the panel temperature increases over the course of time on a sunny day. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2107.02876v3-abstract-full').style.display = 'none'; document.getElementById('2107.02876v3-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 8 June, 2022; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 6 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">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/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/2012.02858">arXiv:2012.02858</a> <span> [<a href="https://arxiv.org/pdf/2012.02858">pdf</a>, <a href="https://arxiv.org/format/2012.02858">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/abf7c3">10.3847/1538-4357/abf7c3 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Strong Near-Infrared Carbon Absorption in the Transitional Type Ia SN 2015bp </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Wyatt%2C+S+D">S. D. Wyatt</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=Hsiao%2C+E+Y">E. Y. Hsiao</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=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=Lundquist%2C+M">M. Lundquist</a>, <a href="/search/astro-ph?searchtype=author&query=Galbany%2C+L">L. Galbany</a>, <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=Diamond%2C+T+R">T. R. Diamond</a>, <a href="/search/astro-ph?searchtype=author&query=Filippenko%2C+A+V">A. V. Filippenko</a>, <a href="/search/astro-ph?searchtype=author&query=Graham%2C+M+L">M. L. Graham</a>, <a href="/search/astro-ph?searchtype=author&query=Hoeflich%2C+P">P. Hoeflich</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+I">N. I. Morrell</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=Phillips%2C+M+M">M. M. Phillips</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> </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="2012.02858v2-abstract-short" style="display: inline;"> Unburned carbon is potentially a powerful probe of Type Ia supernova (SN) explosion mechanisms. We present comprehensive optical and near-infrared (NIR) data on the "transitional" Type Ia SN 2015bp. An early NIR spectrum ($t = -$9.9 days with respect to B-band maximum) displays a striking C I $\lambda1.0693\,渭\rm{m}$ line at $11.9 \times 10^3$~km s$^{-1}$, distinct from the prominent Mg II… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2012.02858v2-abstract-full').style.display = 'inline'; document.getElementById('2012.02858v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2012.02858v2-abstract-full" style="display: none;"> Unburned carbon is potentially a powerful probe of Type Ia supernova (SN) explosion mechanisms. We present comprehensive optical and near-infrared (NIR) data on the "transitional" Type Ia SN 2015bp. An early NIR spectrum ($t = -$9.9 days with respect to B-band maximum) displays a striking C I $\lambda1.0693\,渭\rm{m}$ line at $11.9 \times 10^3$~km s$^{-1}$, distinct from the prominent Mg II $\lambda1.0927\,渭\rm{m}$ feature, which weakens toward maximum light. SN 2015bp also displays a clear C II $\lambda6580$A notch early ($t = -10.9$ days) at $13.2 \times 10^3$~km s$^{-1}$, consistent with our NIR carbon detection. At $M_B = -$18.46, SN 2015bp is less luminous than a normal SN Ia and, along with iPTF13ebh, is the second member of the transitional subclass to display prominent early-time NIR carbon absorption. We find it unlikely that the C I feature is misidentified He I $\lambda1.0830\,渭\rm{m}$ because this feature grows weaker toward maximum light, while the helium line produced in some double-detonation models grows stronger at these times. Intrigued by these strong NIR carbon detections, but lacking NIR data for other SNe Ia, we investigated the incidence of optical carbon in the sample of nine transitional SNe Ia with early-time data ($t \lesssim-$4 days). We find that four display C II $位$6580A, while two others show tentative detections, in line with the SN Ia population as a whole. We conclude that at least $\sim$50% of transitional SNe Ia in our sample do not come from sub-Chandrasekhar mass explosions due to the clear presence of carbon in their NIR and optical spectra. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2012.02858v2-abstract-full').style.display = 'none'; document.getElementById('2012.02858v2-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 5 April, 2021; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 4 December, 2020; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> December 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">23 pages, 12 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/2008.07636">arXiv:2008.07636</a> <span> [<a href="https://arxiv.org/pdf/2008.07636">pdf</a>, <a href="https://arxiv.org/format/2008.07636">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/abafa2">10.3847/1538-4357/abafa2 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Carnegie Supernova Project: Classification of Type Ia Supernovae </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Burrow%2C+A">Anthony Burrow</a>, <a href="/search/astro-ph?searchtype=author&query=Baron%2C+E">E. Baron</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=Morrell%2C+N">N. Morrell</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=Brown%2C+P+J">Peter J. Brown</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=Galbany%2C+L">Llu铆s Galbany</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">Eric Y. Hsiao</a>, <a href="/search/astro-ph?searchtype=author&query=Krisciunas%2C+K">Kevin Krisciunas</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=Piro%2C+A+L">Anthony L. Piro</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=Uddin%2C+S">Syed 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="2008.07636v1-abstract-short" style="display: inline;"> We use the spectroscopy and homogeneous photometry of 97 Type Ia supernovae obtained by the \emph{Carnegie Supernova Project} as well as a subset of 36 Type Ia supernovae presented by Zheng et al. (2018) to examine maximum-light correlations in a four-dimensional (4-D) parameter space: $B$-band absolute magnitude, $M_B$, \ion{Si}{2}~$\lambda6355$ velocity, \vsi, and \ion{Si}{2} pseudo-equivalent w… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2008.07636v1-abstract-full').style.display = 'inline'; document.getElementById('2008.07636v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2008.07636v1-abstract-full" style="display: none;"> We use the spectroscopy and homogeneous photometry of 97 Type Ia supernovae obtained by the \emph{Carnegie Supernova Project} as well as a subset of 36 Type Ia supernovae presented by Zheng et al. (2018) to examine maximum-light correlations in a four-dimensional (4-D) parameter space: $B$-band absolute magnitude, $M_B$, \ion{Si}{2}~$\lambda6355$ velocity, \vsi, and \ion{Si}{2} pseudo-equivalent widths pEW(\ion{Si}{2}~$\lambda6355$) and pEW(\ion{Si}{2}~$\lambda5972$). It is shown using Gaussian mixture models (GMMs) that the original four groups in the Branch diagram are well-defined and robust in this parameterization. We find three continuous groups that describe the behavior of our sample in [$M_B$, \vsi] space. Extending the GMM into the full 4-D space yields a grouping system that only slightly alters group definitions in the [$M_B$, \vsi] projection, showing that most of the clustering information in [$M_B$, \vsi] is already contained in the 2-D GMM groupings. However, the full 4-D space does divide group membership for faster objects between core-normal and broad-line objects in the Branch diagram. A significant correlation between $M_B$ and pEW(\ion{Si}{2}~$\lambda5972$) is found, which implies that Branch group membership can be well-constrained by spectroscopic quantities alone. In general, we find that higher-dimensional GMMs reduce the uncertainty of group membership for objects between the originally defined Branch groups. We also find that the broad-line Branch group becomes nearly distinct with the inclusion of \vsi, indicating that this subclass of SNe Ia may be somehow different from the other groups. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2008.07636v1-abstract-full').style.display = 'none'; document.getElementById('2008.07636v1-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 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, 19 figures, ApJ, in press</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/2006.15164">arXiv:2006.15164</a> <span> [<a href="https://arxiv.org/pdf/2006.15164">pdf</a>, <a href="https://arxiv.org/format/2006.15164">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> <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/abafb7">10.3847/1538-4357/abafb7 <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-I: Correlation Between Type Ia Supernovae and Their Host Galaxies from Optical to Near-Infrared Bands </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">M. 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=Contreras%2C+C">Carlos Contreras</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=Morrell%2C+N">Nidia Morrell</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=Stritzinger%2C+M">Maximilian Stritzinger</a>, <a href="/search/astro-ph?searchtype=author&query=Hoeflich%2C+P">Peter Hoeflich</a>, <a href="/search/astro-ph?searchtype=author&query=Ashall%2C+C">Chris Ashall</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=Freedman%2C+W+L">Wendy L. Freedman</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=Krisciunas%2C+K">Kevin Krisciunas</a>, <a href="/search/astro-ph?searchtype=author&query=Brown%2C+P">Peter Brown</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="2006.15164v3-abstract-short" style="display: inline;"> We present optical and near-infrared ($ugriYJH$) photometry of host galaxies of Type Ia supernovae (SN~Ia) observed by the \textit{Carnegie Supernova Project-I}. We determine host galaxy stellar masses and, for the first time, study their correlation with SN~Ia standardized luminosity across optical and near-infrared ($uBgVriYJH$) bands. In the individual bands, we find that SNe~Ia are more lumino… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2006.15164v3-abstract-full').style.display = 'inline'; document.getElementById('2006.15164v3-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2006.15164v3-abstract-full" style="display: none;"> We present optical and near-infrared ($ugriYJH$) photometry of host galaxies of Type Ia supernovae (SN~Ia) observed by the \textit{Carnegie Supernova Project-I}. We determine host galaxy stellar masses and, for the first time, study their correlation with SN~Ia standardized luminosity across optical and near-infrared ($uBgVriYJH$) bands. In the individual bands, we find that SNe~Ia are more luminous in more massive hosts with luminosity offsets ranging between $-0.07 \pm0.03$ mag to $-0.15\pm0.04$ mag after light-curve standardization. The slope of the SN~Ia Hubble residual-host mass relation is negative across all $uBgVriYJH$ bands with values ranging between $-0.036\pm 0.025$ mag/dex to $-0.097\pm 0.027$ mag/dex -- implying that SNe~Ia in more massive galaxies are brighter than expected. The near-constant observed correlations across optical and near-infrared bands indicate that dust may not play a significant role in the observed luminosity offset--host mass correlation. We measure projected separations between SNe~Ia and their host centers, and find that SNe~Ia that explode beyond a projected 10 kpc have a $\rm 30\% \ to \ 50\%$ reduction of the dispersion in Hubble residuals across all bands -- making them a more uniform subset of SNe~Ia. Dust in host galaxies, peculiar velocities of nearby SN~Ia, or a combination of both may drive this result as the color excesses of SNe~Ia beyond 10 kpc are found to be generally lower than those interior, but there is also a diminishing trend of the dispersion as we exclude nearby events. We do not find that SN~Ia average luminosity varies significantly when they are grouped in various host morphological types. Host galaxy data from this work will be useful, in conjunction with future high-redshift samples, in constraining cosmological parameters. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2006.15164v3-abstract-full').style.display = 'none'; document.getElementById('2006.15164v3-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 14 August, 2020; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 26 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">Accepted to 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/2004.13069">arXiv:2004.13069</a> <span> [<a href="https://arxiv.org/pdf/2004.13069">pdf</a>, <a href="https://arxiv.org/format/2004.13069">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Astrophysics of Galaxies">astro-ph.GA</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="High Energy Astrophysical Phenomena">astro-ph.HE</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.3847/1538-4357/ab8e3e">10.3847/1538-4357/ab8e3e <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> SN 2013aa and SN 2017cbv: Two Sibling Type Ia Supernovae in the spiral galaxy NGC 5643 </p> <p class="authors"> <span class="search-hit">Authors:</span> <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=Contreras%2C+C">Carlos Contreras</a>, <a href="/search/astro-ph?searchtype=author&query=Brown%2C+P">Peter Brown</a>, <a href="/search/astro-ph?searchtype=author&query=Stritzinger%2C+M">Maximilian 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=Flores%2C+R">Ricardo Flores</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=Hsiao%2C+E+Y">Eric Y Hsiao</a>, <a href="/search/astro-ph?searchtype=author&query=Uddin%2C+S">Syed Uddin</a>, <a href="/search/astro-ph?searchtype=author&query=Simon%2C+J+D">Joshua D Simon</a>, <a href="/search/astro-ph?searchtype=author&query=Krisciunas%2C+K">Kevin Krisciunas</a>, <a href="/search/astro-ph?searchtype=author&query=Campillay%2C+A">Abdo Campillay</a>, <a href="/search/astro-ph?searchtype=author&query=Foley%2C+R+J">Ryan J Foley</a>, <a href="/search/astro-ph?searchtype=author&query=Freedman%2C+W+L">Wendy L Freedman</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%2C+C">Consuelo Gonz谩lez</a>, <a href="/search/astro-ph?searchtype=author&query=Hoeflich%2C+P">Peter Hoeflich</a>, <a href="/search/astro-ph?searchtype=author&query=Holmbo%2C+S">S Holmbo</a>, <a href="/search/astro-ph?searchtype=author&query=Kilpatrick%2C+C+D">Charles D Kilpatrick</a>, <a href="/search/astro-ph?searchtype=author&query=Kirshner%2C+R+P">Robert P Kirshner</a>, <a href="/search/astro-ph?searchtype=author&query=Morrell%2C+N">Nidia Morrell</a>, <a href="/search/astro-ph?searchtype=author&query=Mu%C3%B1oz-Elgueta%2C+N">Nahir Mu帽oz-Elgueta</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=Rojas-Bravo%2C+C">C茅sar Rojas-Bravo</a> , et al. (4 additional authors not shown) </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2004.13069v1-abstract-short" style="display: inline;"> We present photometric and spectroscopic observations of SN 2013aa and SN 2017cbv, two nearly identical type Ia supernovae (SNe Ia) in the host galaxy NGC 5643. The optical photometry has been obtained using the same telescope and instruments used by the Carnegie Supernova Project. This eliminates most instrumental systematics and provides light curves in a stable and well-understood photometric s… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2004.13069v1-abstract-full').style.display = 'inline'; document.getElementById('2004.13069v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2004.13069v1-abstract-full" style="display: none;"> We present photometric and spectroscopic observations of SN 2013aa and SN 2017cbv, two nearly identical type Ia supernovae (SNe Ia) in the host galaxy NGC 5643. The optical photometry has been obtained using the same telescope and instruments used by the Carnegie Supernova Project. This eliminates most instrumental systematics and provides light curves in a stable and well-understood photometric system. Having the same host galaxy also eliminates systematics due to distance and peculiar velocity, providing an opportunity to directly test the relative precision of SNe Ia as standard candles. The two SNe have nearly identical decline rates, negligible reddening, and remarkably similar spectra and, at a distance of $\sim 20$ Mpc, are ideal as potential calibrators for the absolute distance using primary indicators such as Cepheid variables. We discuss to what extent these two SNe can be considered twins and compare them with other supernova "siblings" in the literature and their likely progenitor scenarios. Using 12 galaxies that hosted 2 or more SNe~Ia, we find that when using SNe~Ia, and after accounting for all sources of observational error, one gets consistency in distance to 3 percent. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2004.13069v1-abstract-full').style.display = 'none'; document.getElementById('2004.13069v1-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 April, 2020; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> April 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 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/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/1911.05068">arXiv:1911.05068</a> <span> [<a href="https://arxiv.org/pdf/1911.05068">pdf</a>, <a href="https://arxiv.org/format/1911.05068">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="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/10.3847/1538-3881/ab570f">10.3847/1538-3881/ab570f <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> The Vanishing & Appearing Sources during a Century of Observations project: I. USNO objects missing in modern sky surveys and follow-up observations of a "missing star" </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Villarroel%2C+B">Beatriz Villarroel</a>, <a href="/search/astro-ph?searchtype=author&query=Soodla%2C+J">Johan Soodla</a>, <a href="/search/astro-ph?searchtype=author&query=Comer%C3%B3n%2C+S">S茅bastien Comer贸n</a>, <a href="/search/astro-ph?searchtype=author&query=Mattsson%2C+L">Lars Mattsson</a>, <a href="/search/astro-ph?searchtype=author&query=Pelckmans%2C+K">Kristiaan Pelckmans</a>, <a href="/search/astro-ph?searchtype=author&query=L%C3%B3pez-Corredoira%2C+M">Mart铆n L贸pez-Corredoira</a>, <a href="/search/astro-ph?searchtype=author&query=Krisciunas%2C+K">Kevin Krisciunas</a>, <a href="/search/astro-ph?searchtype=author&query=Guerras%2C+E">Eduardo Guerras</a>, <a href="/search/astro-ph?searchtype=author&query=Kochukhov%2C+O">Oleg Kochukhov</a>, <a href="/search/astro-ph?searchtype=author&query=Bergstedt%2C+J">Josefine Bergstedt</a>, <a href="/search/astro-ph?searchtype=author&query=Buelens%2C+B">Bart Buelens</a>, <a href="/search/astro-ph?searchtype=author&query=B%C3%A4r%2C+R+E">Rudolf E. B盲r</a>, <a href="/search/astro-ph?searchtype=author&query=Cubo%2C+R">Rub茅n Cubo</a>, <a href="/search/astro-ph?searchtype=author&query=Enriquez%2C+J+E">J. Emilio Enriquez</a>, <a href="/search/astro-ph?searchtype=author&query=Gupta%2C+A+C">Alok C. Gupta</a>, <a href="/search/astro-ph?searchtype=author&query=Imaz%2C+I">I帽igo Imaz</a>, <a href="/search/astro-ph?searchtype=author&query=Karlsson%2C+T">Torgny Karlsson</a>, <a href="/search/astro-ph?searchtype=author&query=Prieto%2C+M+A">M. Almudena Prieto</a>, <a href="/search/astro-ph?searchtype=author&query=Shlyapnikov%2C+A+A">Aleksey A. Shlyapnikov</a>, <a href="/search/astro-ph?searchtype=author&query=de+Souza%2C+R+S">Rafael S. de Souza</a>, <a href="/search/astro-ph?searchtype=author&query=Vavilova%2C+I+B">Irina B. Vavilova</a>, <a href="/search/astro-ph?searchtype=author&query=Ward%2C+M+J">Martin J. Ward</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="1911.05068v2-abstract-short" style="display: inline;"> In this paper we report the current status of a new research program. The primary goal of the "Vanishing & Appearing Sources during a Century of Observations" (VASCO) project is to search for vanishing and appearing sources using existing survey data to find examples of exceptional astrophysical transients. The implications of finding such objects extend from traditional astrophysics fields to the… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1911.05068v2-abstract-full').style.display = 'inline'; document.getElementById('1911.05068v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1911.05068v2-abstract-full" style="display: none;"> In this paper we report the current status of a new research program. The primary goal of the "Vanishing & Appearing Sources during a Century of Observations" (VASCO) project is to search for vanishing and appearing sources using existing survey data to find examples of exceptional astrophysical transients. The implications of finding such objects extend from traditional astrophysics fields to the more exotic searches for evidence of technologically advanced civilizations. In this first paper we present new, deeper observations of the tentative candidate discovered by Villarroel et al. (2016). We then perform the first searches for vanishing objects throughout the sky by comparing 600 million objects from the US Naval Observatory Catalogue (USNO) B1.0 down to a limiting magnitude of $\sim 20 - 21$ with the recent Pan-STARRS Data Release-1 (DR1) with a limiting magnitude of $\sim$ 23.4. We find about 150,000 preliminary candidates that do not have any Pan-STARRS counterpart within a 30 arcsec radius. We show that these objects are redder and have larger proper motions than typical USNO objects. We visually examine the images for a subset of about 24,000 candidates, superseding the 2016 study with a sample ten times larger. We find about $\sim$ 100 point sources visible in only one epoch in the red band of the USNO which may be of interest in searches for strong M dwarf flares, high-redshift supernovae or other catagories of unidentified red transients. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1911.05068v2-abstract-full').style.display = 'none'; document.getElementById('1911.05068v2-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 November, 2019; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 12 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">SETI meets time domain astronomy. Accepted into the Astronomical 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/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/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/1903.04553">arXiv:1903.04553</a> <span> [<a href="https://arxiv.org/pdf/1903.04553">pdf</a>, <a href="https://arxiv.org/ps/1903.04553">ps</a>, <a href="https://arxiv.org/format/1903.04553">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="Cosmology and Nongalactic Astrophysics">astro-ph.CO</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"> Gravity and Light: Combining Gravitational Wave and Electromagnetic Observations in the 2020s </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Foley%2C+R+J">R. J. Foley</a>, <a href="/search/astro-ph?searchtype=author&query=Alexander%2C+K+D">K. D. Alexander</a>, <a href="/search/astro-ph?searchtype=author&query=Andreoni%2C+I">I. Andreoni</a>, <a href="/search/astro-ph?searchtype=author&query=Arcavi%2C+I">I. Arcavi</a>, <a href="/search/astro-ph?searchtype=author&query=Auchettl%2C+K">K. Auchettl</a>, <a href="/search/astro-ph?searchtype=author&query=Barnes%2C+J">J. Barnes</a>, <a href="/search/astro-ph?searchtype=author&query=Baym%2C+G">G. Baym</a>, <a href="/search/astro-ph?searchtype=author&query=Bellm%2C+E+C">E. C. Bellm</a>, <a href="/search/astro-ph?searchtype=author&query=Beloborodov%2C+A+M">A. M. Beloborodov</a>, <a href="/search/astro-ph?searchtype=author&query=Blagorodnova%2C+N">N. Blagorodnova</a>, <a href="/search/astro-ph?searchtype=author&query=Blakeslee%2C+J+P">J. P. Blakeslee</a>, <a href="/search/astro-ph?searchtype=author&query=Brady%2C+P+R">P. R. Brady</a>, <a href="/search/astro-ph?searchtype=author&query=Branchesi%2C+M">M. Branchesi</a>, <a href="/search/astro-ph?searchtype=author&query=Brown%2C+J+S">J. S. Brown</a>, <a href="/search/astro-ph?searchtype=author&query=Butler%2C+N">N. Butler</a>, <a href="/search/astro-ph?searchtype=author&query=Cantiello%2C+M">M. Cantiello</a>, <a href="/search/astro-ph?searchtype=author&query=Chornock%2C+R">R. Chornock</a>, <a href="/search/astro-ph?searchtype=author&query=Cook%2C+D+O">D. O. Cook</a>, <a href="/search/astro-ph?searchtype=author&query=Cooke%2C+J">J. Cooke</a>, <a href="/search/astro-ph?searchtype=author&query=Coppejans%2C+D+L">D. L. Coppejans</a>, <a href="/search/astro-ph?searchtype=author&query=Corsi%2C+A">A. Corsi</a>, <a href="/search/astro-ph?searchtype=author&query=Couch%2C+S+M">S. M. Couch</a>, <a href="/search/astro-ph?searchtype=author&query=Coughlin%2C+M+W">M. W. Coughlin</a>, <a href="/search/astro-ph?searchtype=author&query=Coulter%2C+D+A">D. A. Coulter</a>, <a href="/search/astro-ph?searchtype=author&query=Cowperthwaite%2C+P+S">P. S. Cowperthwaite</a> , et al. (88 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="1903.04553v1-abstract-short" style="display: inline;"> As of today, we have directly detected exactly one source in both gravitational waves (GWs) and electromagnetic (EM) radiation, the binary neutron star merger GW170817, its associated gamma-ray burst GRB170817A, and the subsequent kilonova SSS17a/AT 2017gfo. Within ten years, we will detect hundreds of events, including new classes of events such as neutron-star-black-hole mergers, core-collapse s… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1903.04553v1-abstract-full').style.display = 'inline'; document.getElementById('1903.04553v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1903.04553v1-abstract-full" style="display: none;"> As of today, we have directly detected exactly one source in both gravitational waves (GWs) and electromagnetic (EM) radiation, the binary neutron star merger GW170817, its associated gamma-ray burst GRB170817A, and the subsequent kilonova SSS17a/AT 2017gfo. Within ten years, we will detect hundreds of events, including new classes of events such as neutron-star-black-hole mergers, core-collapse supernovae, and almost certainly something completely unexpected. As we build this sample, we will explore exotic astrophysical topics ranging from nucleosynthesis, stellar evolution, general relativity, high-energy astrophysics, nuclear matter, to cosmology. The discovery potential is extraordinary, and investments in this area will yield major scientific breakthroughs. Here we outline some of the most exciting scientific questions that can be answered by combining GW and EM observations. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1903.04553v1-abstract-full').style.display = 'none'; document.getElementById('1903.04553v1-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 March, 2019; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> March 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 Astro2020</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/1812.04982">arXiv:1812.04982</a> <span> [<a href="https://arxiv.org/pdf/1812.04982">pdf</a>, <a href="https://arxiv.org/ps/1812.04982">ps</a>, <a href="https://arxiv.org/format/1812.04982">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> <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/10.1093/mnras/sty3396">10.1093/mnras/sty3396 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Type II Supernovae as Distance Indicators at Near-IR Wavelengths </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Rodr%C3%ADguez%2C+%C3%93">脫. Rodr铆guez</a>, <a href="/search/astro-ph?searchtype=author&query=Pignata%2C+G">G. Pignata</a>, <a href="/search/astro-ph?searchtype=author&query=Hamuy%2C+M">M. Hamuy</a>, <a href="/search/astro-ph?searchtype=author&query=Clocchiatti%2C+A">A. Clocchiatti</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=Krisciunas%2C+K">K. Krisciunas</a>, <a href="/search/astro-ph?searchtype=author&query=Morrell%2C+N+I">N. I. Morrell</a>, <a href="/search/astro-ph?searchtype=author&query=Folatelli%2C+G">G. Folatelli</a>, <a href="/search/astro-ph?searchtype=author&query=Roth%2C+M">M. Roth</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=Jang%2C+I+S">I. S. Jang</a>, <a href="/search/astro-ph?searchtype=author&query=Apostolovski%2C+Y">Y. Apostolovski</a>, <a href="/search/astro-ph?searchtype=author&query=L%C3%B3pez%2C+P">P. L贸pez</a>, <a href="/search/astro-ph?searchtype=author&query=Marchi%2C+S">S. Marchi</a>, <a href="/search/astro-ph?searchtype=author&query=Ram%C3%ADrez%2C+R">R. Ram铆rez</a>, <a href="/search/astro-ph?searchtype=author&query=S%C3%A1nchez%2C+P">P. S谩nchez</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="1812.04982v1-abstract-short" style="display: inline;"> Motivated by the advantages of observing at near-IR wavelengths, we investigate Type II supernovae (SNe II) as distance indicators at those wavelengths through the Photospheric Magnitude Method (PMM). For the analysis, we use $BVIJH$ photometry and optical spectroscopy of 24 SNe II during the photospheric phase. To correct photometry for extinction and redshift effects, we compute total-to-selecti… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1812.04982v1-abstract-full').style.display = 'inline'; document.getElementById('1812.04982v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1812.04982v1-abstract-full" style="display: none;"> Motivated by the advantages of observing at near-IR wavelengths, we investigate Type II supernovae (SNe II) as distance indicators at those wavelengths through the Photospheric Magnitude Method (PMM). For the analysis, we use $BVIJH$ photometry and optical spectroscopy of 24 SNe II during the photospheric phase. To correct photometry for extinction and redshift effects, we compute total-to-selective broadband extinction ratios and $K$-corrections up to $z=0.032$. To estimate host galaxy colour excesses, we use the colour-colour curve method with the $V\!-\!I$ versus $B\!-\!V$ as colour combination. We calibrate the PMM using four SNe II in galaxies having Tip of the Red Giant Branch distances. Among our 24 SNe II, nine are at $cz>2000$ km s$^{-1}$, which we use to construct Hubble diagrams (HDs). To further explore the PMM distance precision, we include into HDs the four SNe used for calibration and other two in galaxies with Cepheid and SN Ia distances. With a set of 15 SNe II we obtain a HD rms of 0.13 mag for the $J$-band, which compares to the rms of 0.15-0.26 mag for optical bands. This reflects the benefits of measuring PMM distances with near-IR instead of optical photometry. With the evidence we have, we can set the PMM distance precision with $J$-band below 10 per cent with a confidence level of 99 per cent. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1812.04982v1-abstract-full').style.display = 'none'; document.getElementById('1812.04982v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 12 December, 2018; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> December 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">24 pages, 13 figures. Accepted for publication 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/1811.08969">arXiv:1811.08969</a> <span> [<a href="https://arxiv.org/pdf/1811.08969">pdf</a>, <a href="https://arxiv.org/ps/1811.08969">ps</a>, <a href="https://arxiv.org/format/1811.08969">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="Cosmology and Nongalactic Astrophysics">astro-ph.CO</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/sty3178">10.1093/mnras/sty3178 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Probing type Ia supernova properties using bolometric light curves from the Carnegie Supernova Project and the CfA Supernova Group </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Scalzo%2C+R+A">Richard A. Scalzo</a>, <a href="/search/astro-ph?searchtype=author&query=Parent%2C+E">Emilie Parent</a>, <a href="/search/astro-ph?searchtype=author&query=Burns%2C+C">Christopher Burns</a>, <a href="/search/astro-ph?searchtype=author&query=Childress%2C+M+J">Michael J. Childress</a>, <a href="/search/astro-ph?searchtype=author&query=Tucker%2C+B+E">Brad E. Tucker</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=Contreras%2C+C">Carlos Contreras</a>, <a href="/search/astro-ph?searchtype=author&query=Hsiao%2C+E">Eric Hsiao</a>, <a href="/search/astro-ph?searchtype=author&query=Krisciunas%2C+K">Kevin Krisciunas</a>, <a href="/search/astro-ph?searchtype=author&query=Morrell%2C+N">Nidia Morrell</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=Piro%2C+A+L">Anthony L. Piro</a>, <a href="/search/astro-ph?searchtype=author&query=Stritzinger%2C+M">Maximilian Stritzinger</a>, <a href="/search/astro-ph?searchtype=author&query=Suntzeff%2C+N">Nicholas Suntzeff</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="1811.08969v1-abstract-short" style="display: inline;"> We present bolometric light curves constructed from multi-wavelength photometry of Type Ia supernovae (SNe Ia) from the Carnegie Supernova Project and the CfA Supernova Group, using near-infrared observations to provide robust constraints on host galaxy dust extinction. This set of light curves form a well-measured reference set for comparison with theoretical models. Ejected mass and synthesized… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1811.08969v1-abstract-full').style.display = 'inline'; document.getElementById('1811.08969v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1811.08969v1-abstract-full" style="display: none;"> We present bolometric light curves constructed from multi-wavelength photometry of Type Ia supernovae (SNe Ia) from the Carnegie Supernova Project and the CfA Supernova Group, using near-infrared observations to provide robust constraints on host galaxy dust extinction. This set of light curves form a well-measured reference set for comparison with theoretical models. Ejected mass and synthesized $^{56}$Ni mass are inferred for each SN Ia from its bolometric light curve using a semi-analytic Bayesian light curve model, and fitting formulae provided in terms of light curve width parameters from the SALT2 and SNooPy light curve fitters. A weak bolometric width-luminosity relation is confirmed, along with a correlation between ejected mass and the bolometric light curve width. SNe Ia likely to have sub-Chandrasekhar ejected masses belong preferentially to the broad-line and cool-photosphere spectroscopic subtypes, and have higher photospheric velocities and populate older, higher-mass host galaxies than SNe Ia consistent with Chandrasekhar-mass explosions. Two peculiar events, SN 2006bt and SN 2006ot, have normal peak luminosities but appear to have super-Chandrasekhar ejected masses. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1811.08969v1-abstract-full').style.display = 'none'; document.getElementById('1811.08969v1-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 November, 2018; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> November 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">26 pages, 14 figures; accepted to MNRAS. An online-only appendix in the MNRAS version is included as a supplemental appendix to the arXiv text; online-only tables, including bolometric light curves and MCMC inversion results, are included as ancillary files</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1810.09252">arXiv:1810.09252</a> <span> [<a href="https://arxiv.org/pdf/1810.09252">pdf</a>, <a href="https://arxiv.org/format/1810.09252">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/10.1088/1538-3873/aae8bd">10.1088/1538-3873/aae8bd <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: Extending the Near-Infrared Hubble Diagram for Type Ia Supernovae to $z\sim0.1$ </p> <p class="authors"> <span class="search-hit">Authors:</span> <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">Carlos Contreras</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=Morrell%2C+N">Nidia Morrell</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=Stritzinger%2C+M">Maximilian Stritzinger</a>, <a href="/search/astro-ph?searchtype=author&query=Ashall%2C+C">C. Ashall</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=Hoeflich%2C+P">P. Hoeflich</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=Suntzeff%2C+N+B">Nicholas B. Suntzeff</a>, <a href="/search/astro-ph?searchtype=author&query=Uddin%2C+S+A">Syed A. Uddin</a>, <a href="/search/astro-ph?searchtype=author&query=Anais%2C+J">Jorge Anais</a>, <a href="/search/astro-ph?searchtype=author&query=Baron%2C+E">E. Baron</a>, <a href="/search/astro-ph?searchtype=author&query=Busta%2C+L">Luis Busta</a>, <a href="/search/astro-ph?searchtype=author&query=Campillay%2C+A">Abdo Campillay</a>, <a href="/search/astro-ph?searchtype=author&query=Castell%C3%B3n%2C+S">Sergio Castell贸n</a>, <a href="/search/astro-ph?searchtype=author&query=Corco%2C+C">Carlos Corco</a>, <a href="/search/astro-ph?searchtype=author&query=Diamond%2C+T">T. Diamond</a>, <a href="/search/astro-ph?searchtype=author&query=Gall%2C+C">Christa Gall</a>, <a href="/search/astro-ph?searchtype=author&query=Gonzalez%2C+C">Consuelo Gonzalez</a>, <a href="/search/astro-ph?searchtype=author&query=Holmbo%2C+S">Simon Holmbo</a>, <a href="/search/astro-ph?searchtype=author&query=Krisciunas%2C+K">Kevin Krisciunas</a>, <a href="/search/astro-ph?searchtype=author&query=Roth%2C+M">Miguel Roth</a> , et al. (19 additional authors not shown) </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="1810.09252v1-abstract-short" style="display: inline;"> The Carnegie Supernova Project-II (CSP-II) was an NSF-funded, four-year program to obtain optical and near-infrared observations of a "Cosmology" sample of $\sim100$ Type Ia supernovae located in the smooth Hubble flow ($0.03 \lesssim z \lesssim 0.10$). Light curves were also obtained of a "Physics" sample composed of 90 nearby Type Ia supernovae at $z \leq 0.04$ selected for near-infrared spectro… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1810.09252v1-abstract-full').style.display = 'inline'; document.getElementById('1810.09252v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1810.09252v1-abstract-full" style="display: none;"> The Carnegie Supernova Project-II (CSP-II) was an NSF-funded, four-year program to obtain optical and near-infrared observations of a "Cosmology" sample of $\sim100$ Type Ia supernovae located in the smooth Hubble flow ($0.03 \lesssim z \lesssim 0.10$). Light curves were also obtained of a "Physics" sample composed of 90 nearby Type Ia supernovae at $z \leq 0.04$ selected for near-infrared spectroscopic time-series observations. The primary emphasis of the CSP-II is to use the combination of optical and near-infrared photometry to achieve a distance precision of better than 5%. In this paper, details of the supernova sample, the observational strategy, and the characteristics of the photometric data are provided. In a companion paper, the near-infrared spectroscopy component of the project is presented. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1810.09252v1-abstract-full').style.display = 'none'; document.getElementById('1810.09252v1-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 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">43 pages, 10 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/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/1810.01149">arXiv:1810.01149</a> <span> [<a href="https://arxiv.org/pdf/1810.01149">pdf</a>, <a href="https://arxiv.org/format/1810.01149">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/aaef34">10.3847/1538-4357/aaef34 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Investigating the Unusual Spectroscopic Time-Evolution in SN 2012fr </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Cain%2C+C">C. Cain</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=Ashall%2C+C">C. Ashall</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=Burns%2C+C">C. Burns</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=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=Krisciunas%2C+K">K. Krisciunas</a>, <a href="/search/astro-ph?searchtype=author&query=Suntzeff%2C+N+B">N. B. Suntzeff</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="1810.01149v2-abstract-short" style="display: inline;"> The type Ia supernova (SN) 2012fr displayed an unusual combination of its Si II 位位5972, 6355 features. This includes the ratio of their pseudo equivalent widths, placing it at the border of the Shallow Silicon (SS) and Core Normal (CN) spectral subtype in the Branch diagram, while the Si II 位6355 expansion velocities places it as a High-Velocity (HV) object in the Wang et al. spectral type that mo… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1810.01149v2-abstract-full').style.display = 'inline'; document.getElementById('1810.01149v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1810.01149v2-abstract-full" style="display: none;"> The type Ia supernova (SN) 2012fr displayed an unusual combination of its Si II 位位5972, 6355 features. This includes the ratio of their pseudo equivalent widths, placing it at the border of the Shallow Silicon (SS) and Core Normal (CN) spectral subtype in the Branch diagram, while the Si II 位6355 expansion velocities places it as a High-Velocity (HV) object in the Wang et al. spectral type that most interestingly evolves slowly, placing it in the Low Velocity Gradient (LVG) typing of Benetti et al. Only 5% of SNe Ia are HV and located in the SS+CN portion of the Branch diagram and less than 10% of SNe Ia are both HV and LVG. These features point towards SN 2012fr being quite unusual, similar in many ways to the peculiar SN 2000cx. We modeled the spectral evolution of SN 2012fr to see if we could gain some insight into its evolutionary behavior. We use the parameterized radiative transfer code SYNOW to probe the abundance stratification of SN 2012fr at pre-maximum, maximum, and post-maximum light epochs. We also use a grid of W7 models in the radiative transfer code PHOENIX to probe the effect of different density structures on the formation of the Si II 位6355 absorption feature at post-maximum epochs. We find that the unusual features observed in SN 2012fr are likely due to a shell-like density enhancement in the outer ejecta. We comment on possible reasons for atypical Ca II absorption features, and suggest that they are related to the Si II features. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1810.01149v2-abstract-full').style.display = 'none'; document.getElementById('1810.01149v2-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 October, 2018; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 2 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">26 pages, 13 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/1809.06381">arXiv:1809.06381</a> <span> [<a href="https://arxiv.org/pdf/1809.06381">pdf</a>, <a href="https://arxiv.org/format/1809.06381">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 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/aae51c">10.3847/1538-4357/aae51c <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: Absolute Calibration and the Hubble Constant </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Burns%2C+C+R">Christopher. R. Burns</a>, <a href="/search/astro-ph?searchtype=author&query=Parent%2C+E">Emilie Parent</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">Maximillian Stritzinger</a>, <a href="/search/astro-ph?searchtype=author&query=Krisciunas%2C+K">Kevin Krisciunas</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=Hsiao%2C+E+Y">Eric Y. Hsiao</a>, <a href="/search/astro-ph?searchtype=author&query=Contreras%2C+C">Carlos Contreras</a>, <a href="/search/astro-ph?searchtype=author&query=Anais%2C+J">Jorge Anais</a>, <a href="/search/astro-ph?searchtype=author&query=Boldt%2C+L">Luis Boldt</a>, <a href="/search/astro-ph?searchtype=author&query=Busta%2C+L">Luis Busta</a>, <a href="/search/astro-ph?searchtype=author&query=Campillay%2C+A">Abdo Campillay</a>, <a href="/search/astro-ph?searchtype=author&query=Castellon%2C+S">Sergio Castellon</a>, <a href="/search/astro-ph?searchtype=author&query=Folatelli%2C+G">Gaston 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=Gonzalez%2C+C">Consuelo Gonzalez</a>, <a href="/search/astro-ph?searchtype=author&query=Hamuy%2C+M">Mario Hamuy</a>, <a href="/search/astro-ph?searchtype=author&query=Heoflich%2C+P">Peter Heoflich</a>, <a href="/search/astro-ph?searchtype=author&query=Krzeminski%2C+W">Wojtek Krzeminski</a>, <a href="/search/astro-ph?searchtype=author&query=Madore%2C+B+F">Barry F. Madore</a>, <a href="/search/astro-ph?searchtype=author&query=Morrell%2C+N">Nidia Morrell</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=Roth%2C+M">Miguel Roth</a>, <a href="/search/astro-ph?searchtype=author&query=Salgado%2C+F">Francisco Salgado</a>, <a href="/search/astro-ph?searchtype=author&query=Seron%2C+J">Jacqueline Seron</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="1809.06381v2-abstract-short" style="display: inline;"> We present an analysis of the final data release of the Carnegie Supernova Project I, focusing on the absolute calibration of the luminosity-decline-rate relation for Type Ia supernovae (SNeIa) using new intrinsic color relations with respect to the color-stretch parameter, $s_{BV}$, enabling improved dust extinction corrections. We investigate to what degree the so-called fast-declining SNeIa can… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1809.06381v2-abstract-full').style.display = 'inline'; document.getElementById('1809.06381v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1809.06381v2-abstract-full" style="display: none;"> We present an analysis of the final data release of the Carnegie Supernova Project I, focusing on the absolute calibration of the luminosity-decline-rate relation for Type Ia supernovae (SNeIa) using new intrinsic color relations with respect to the color-stretch parameter, $s_{BV}$, enabling improved dust extinction corrections. We investigate to what degree the so-called fast-declining SNeIa can be used to determine accurate extragalactic distances. We estimate the intrinsic scatter in the luminosity-decline-rate relation, and find it ranges from $\pm 0.13$ mag to $\pm 0.18$ mag with no obvious dependence on wavelength. Using the Cepheid variable star data from the SH0ES project (Riess et al., 2016), the SNIa distance scale is calibrated and the Hubble constant is estimated using our optical and near-infrared sample, and these results are compared to those determined exclusively from a near-infrared sub-sample. The systematic effect of the supernova's host galaxy mass is investigated as a function of wavelength and is found to decrease toward redder wavelengths, suggesting this effect may be due to dust properties of the host. Using estimates of the dust extinction derived from optical and NIR wavelengths, and applying these to H band, we derive a Hubble constant $H_0 = 73.2 \pm 2.3$ km/s/Mpc, whereas using a simple $B-V$ color-correction applied to B band yields $H_0 = 72.7 \pm 2.1$ km/s/Mpc. Photometry of two calibrating SNeIa from the CSP-II sample, SN2012ht and SN2015F, is presented and used to improve the calibration of the SNIa distance ladder. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1809.06381v2-abstract-full').style.display = 'none'; document.getElementById('1809.06381v2-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 19 September, 2018; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 17 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">Version 2: fixed author list. Originally submitted to ApJ Aug 30, 2018. Re-submitted Sept 12, 2018 following referee's report. 28 pages, 12 figures, 11 tables</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1809.01359">arXiv:1809.01359</a> <span> [<a href="https://arxiv.org/pdf/1809.01359">pdf</a>, <a href="https://arxiv.org/format/1809.01359">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/10.1051/0004-6361/201834389">10.1051/0004-6361/201834389 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> The first 48: Discovery and progenitor constraints on the Type Ia supernova 2013gy </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Holmbo%2C+S">S. Holmbo</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+J">B. J. Shappee</a>, <a href="/search/astro-ph?searchtype=author&query=Tucker%2C+M+A">M. A. Tucker</a>, <a href="/search/astro-ph?searchtype=author&query=Zheng%2C+W">W. Zheng</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=Contreras%2C+C">C. Contreras</a>, <a href="/search/astro-ph?searchtype=author&query=Filippenko%2C+A+V">A. V. Filippenko</a>, <a href="/search/astro-ph?searchtype=author&query=Hoeflich%2C+P">P. Hoeflich</a>, <a href="/search/astro-ph?searchtype=author&query=Huber%2C+M">M. Huber</a>, <a href="/search/astro-ph?searchtype=author&query=Wang%2C+X+F">X. F. Wang</a>, <a href="/search/astro-ph?searchtype=author&query=Zhang%2C+J+-">J. -J. Zhang</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=Burns%2C+C+R">C. R. Burns</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=Hsiao%2C+E+Y">E. Y. Hsiao</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=Nielsen%2C+M+T+B">M. T. B. Nielsen</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">A. Piro</a> , et al. (4 additional authors not shown) </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="1809.01359v1-abstract-short" style="display: inline;"> We present an early-phase $g$-band light curve and visual-wavelength spectra of the normal Type Ia supernova (SN) 2013gy. The light curve is constructed by determining the appropriate S-corrections to transform KAIT natural-system $B$- and $V$-band photometry and Carnegie Supernova Project natural-system $g$-band photometry to the Pan-STARRS1 $g$-band natural photometric system. A Markov Chain Mon… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1809.01359v1-abstract-full').style.display = 'inline'; document.getElementById('1809.01359v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1809.01359v1-abstract-full" style="display: none;"> We present an early-phase $g$-band light curve and visual-wavelength spectra of the normal Type Ia supernova (SN) 2013gy. The light curve is constructed by determining the appropriate S-corrections to transform KAIT natural-system $B$- and $V$-band photometry and Carnegie Supernova Project natural-system $g$-band photometry to the Pan-STARRS1 $g$-band natural photometric system. A Markov Chain Monte Carlo calculation provides a best-fit single power-law function to the first ten epochs of photometry described by an exponent of $2.16^{+0.06}_{-0.06}$ and a time of first light of MJD 56629.4$^{+0.1}_{-0.1}$, which is $1.93^{+0.12}_{-0.13}$ days (i.e., $<48$~hr) before the discovery date (2013 December 4.84 UT) and $-19.10^{+0.12}_{-0.13}$ days before the time of $B$-band maximum (MJD 56648.5$\pm0.1$). The estimate of the time of first light is consistent with the explosion time inferred from the evolution of the Si II $位$6355 Doppler velocity. Furthermore, discovery photometry and previous nondetection limits enable us to constrain the companion radius down to $R_c \leq 4\,R_{\odot}$. In addition to our early-time constraints, we use a deep +235 day nebular-phase spectrum from Magellan/IMACS to place a stripped H-mass limit of $< 0.018\,M_{\odot}$. Combined, these limits effectively rule out H-rich nondegenerate companions. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1809.01359v1-abstract-full').style.display = 'none'; document.getElementById('1809.01359v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 5 September, 2018; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> September 2018. </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1803.10095">arXiv:1803.10095</a> <span> [<a href="https://arxiv.org/pdf/1803.10095">pdf</a>, <a href="https://arxiv.org/format/1803.10095">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/aabaf8">10.3847/1538-4357/aabaf8 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> SN 2012fr: Ultraviolet, Optical, and Near-Infrared Light Curves of a Type Ia Supernova Observed Within a Day of Explosion </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Contreras%2C+C">Carlos Contreras</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=Burns%2C+C+R">Christopher R. Burns</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=Shappee%2C+B+J">B. J. Shappee</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=Baltay%2C+C">C. Baltay</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=Conseil%2C+E">Emmanuel Conseil</a>, <a href="/search/astro-ph?searchtype=author&query=Klotz%2C+A">Alain Klotz</a>, <a href="/search/astro-ph?searchtype=author&query=Nugent%2C+P+E">Peter E. Nugent</a>, <a href="/search/astro-ph?searchtype=author&query=Turpin%2C+D">Damien Turpin</a>, <a href="/search/astro-ph?searchtype=author&query=Parker%2C+S">Stu Parker</a>, <a href="/search/astro-ph?searchtype=author&query=Rabinowitz%2C+D">D. Rabinowitz</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=Morrell%2C+N">Nidia Morrell</a>, <a href="/search/astro-ph?searchtype=author&query=Campillay%2C+A">Abdo Campillay</a>, <a href="/search/astro-ph?searchtype=author&query=Castell%C3%B3n%2C+S">Sergio Castell贸n</a>, <a href="/search/astro-ph?searchtype=author&query=Corco%2C+C">Carlos Corco</a>, <a href="/search/astro-ph?searchtype=author&query=Gonz%C3%A1lez%2C+C">Consuelo Gonz谩lez</a>, <a href="/search/astro-ph?searchtype=author&query=Krisciunas%2C+K">Kevin Krisciunas</a>, <a href="/search/astro-ph?searchtype=author&query=Ser%C3%B3n%2C+J">Jacqueline Ser贸n</a>, <a href="/search/astro-ph?searchtype=author&query=Tucker%2C+B+E">Brad E. Tucker</a>, <a href="/search/astro-ph?searchtype=author&query=Walker%2C+E+S">E. S. Walker</a>, <a href="/search/astro-ph?searchtype=author&query=Baron%2C+E">E. Baron</a> , et al. (10 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="1803.10095v3-abstract-short" style="display: inline;"> We present detailed ultraviolet, optical and near-infrared light curves of the Type Ia supernova (SN) 2012fr, which exploded in the Fornax cluster member NGC 1365. These precise high-cadence light curves provide a dense coverage of the flux evolution from $-$12 to $+$140 days with respect to the epoch of $B$-band maximum (\tmax). Supplementary imaging at the earliest epochs reveals an initial slow… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1803.10095v3-abstract-full').style.display = 'inline'; document.getElementById('1803.10095v3-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1803.10095v3-abstract-full" style="display: none;"> We present detailed ultraviolet, optical and near-infrared light curves of the Type Ia supernova (SN) 2012fr, which exploded in the Fornax cluster member NGC 1365. These precise high-cadence light curves provide a dense coverage of the flux evolution from $-$12 to $+$140 days with respect to the epoch of $B$-band maximum (\tmax). Supplementary imaging at the earliest epochs reveals an initial slow, nearly linear rise in luminosity with a duration of $\sim$2.5 days, followed by a faster rising phase that is well reproduced by an explosion model with a moderate amount of $^{56}$Ni mixing in the ejecta. From an analysis of the light curves, we conclude: $(i)$ explosion occurred $< 22$ hours before the first detection of the supernova, $(ii)$ the rise time to peak bolometric ($位> 1800 $脜) luminosity was $16.5 \pm 0.6$ days, $(iii)$ the supernova suffered little or no host-galaxy dust reddening, $(iv)$ the peak luminosity in both the optical and near-infrared was consistent with the bright end of normal Type Ia diversity, and $(v)$ $0.60 \pm 0.15 M_{\odot}$ of $^{56}$Ni was synthesized in the explosion. Despite its normal luminosity, SN 2012fr displayed unusually prevalent high-velocity \ion{Ca}{2} and \ion{Si}{2} absorption features, and a nearly constant photospheric velocity of the \ion{Si}{2} $位$6355 line at $\sim$12,000 \kms\ beginning $\sim$5 days before \tmax. Other peculiarities in the early phase photometry and the spectral evolution are highlighted. SN 2012fr also adds to a growing number of Type Ia supernovae hosted by galaxies with direct Cepheid distance measurements. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1803.10095v3-abstract-full').style.display = 'none'; document.getElementById('1803.10095v3-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 13 April, 2018; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 27 March, 2018; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> March 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">88 pages, 29 figures, 12 tables</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1711.10345">arXiv:1711.10345</a> <span> [<a href="https://arxiv.org/pdf/1711.10345">pdf</a>, <a href="https://arxiv.org/ps/1711.10345">ps</a>, <a href="https://arxiv.org/format/1711.10345">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> <p class="title is-5 mathjax"> Optical and Infrared Photometry of SN 2005df </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Krisciunas%2C+K">Kevin Krisciunas</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=Espinoza%2C+J">Juan Espinoza</a>, <a href="/search/astro-ph?searchtype=author&query=Gonzalez%2C+D">David Gonzalez</a>, <a href="/search/astro-ph?searchtype=author&query=Miranda%2C+A">Alberto Miranda</a>, <a href="/search/astro-ph?searchtype=author&query=Sanhueza%2C+P">Pedro Sanhueza</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="1711.10345v1-abstract-short" style="display: inline;"> We present optical BVRI and near-infrared YJHK_s photometry of the normal Type Ia supernova 2005df, obtained with the CTIO 1.3-m and 0.9-m telescopes. The B- and V-band photometry, S-corrected to the filter prescriptions of Bessell(1990), matches the corresponding photometry from the ANU published by Milne et al. (2010). The R-band photometry from CTIO and ANU matches well without any corrections.… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1711.10345v1-abstract-full').style.display = 'inline'; document.getElementById('1711.10345v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1711.10345v1-abstract-full" style="display: none;"> We present optical BVRI and near-infrared YJHK_s photometry of the normal Type Ia supernova 2005df, obtained with the CTIO 1.3-m and 0.9-m telescopes. The B- and V-band photometry, S-corrected to the filter prescriptions of Bessell(1990), matches the corresponding photometry from the ANU published by Milne et al. (2010). The R-band photometry from CTIO and ANU matches well without any corrections. A combination of V-band and near-IR photometry shows that SN 2005df is unreddened in its host galaxy. Spectropolarimetry of this supernova was obtained with the VLT, and the distance to the host galaxy is being determined from observations of Cepheids using the Hubble Space Telescope. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1711.10345v1-abstract-full').style.display = 'none'; document.getElementById('1711.10345v1-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, 2017; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> November 2017. </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">12 pages, 3 figures, to be published in Research Notes of the AAS</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1711.03154">arXiv:1711.03154</a> <span> [<a href="https://arxiv.org/pdf/1711.03154">pdf</a>, <a href="https://arxiv.org/ps/1711.03154">ps</a>, <a href="https://arxiv.org/format/1711.03154">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> <p class="title is-5 mathjax"> Why is the Main Sequence of NGC 2482 So Fat? </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Krisciunas%2C+K">Kevin Krisciunas</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=Nagasawa%2C+D+Q">Daniel Q. Nagasawa</a>, <a href="/search/astro-ph?searchtype=author&query=Johnson%2C+M+C">Marshall C. Johnson</a>, <a href="/search/astro-ph?searchtype=author&query=Cochran%2C+W">William Cochran</a>, <a href="/search/astro-ph?searchtype=author&query=Endl%2C+M">Michael Endl</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="1711.03154v1-abstract-short" style="display: inline;"> We present the results of high resolution spectra of seven stars in the field of NGC 2482, an open star cluster of age 447 Myr. We confirm the previously published values of the radial velocity and metallicity of one giant star. This gives us confidence that another giant star is a bona fide cluster member, and that three stars significantly above the main sequence in a color-magnitude diagram are… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1711.03154v1-abstract-full').style.display = 'inline'; document.getElementById('1711.03154v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1711.03154v1-abstract-full" style="display: none;"> We present the results of high resolution spectra of seven stars in the field of NGC 2482, an open star cluster of age 447 Myr. We confirm the previously published values of the radial velocity and metallicity of one giant star. This gives us confidence that another giant star is a bona fide cluster member, and that three stars significantly above the main sequence in a color-magnitude diagram are not members, on the basis of discordant radial velocities. Another star ~1.7 mag above the main sequence may or may not be a member. Its [Fe/H] value is ~0.1 dex more positive than two giant stars studied, and its radial velocity is 3-4 km/s less than that of the two giant stars, which is a significant difference if the velocity dispersion of the cluster is less than +/-1 km/s. To a large extent the width of the main sequence seems to be due to the presence of foreground and background stars in the same general direction, stars that masquerade as main sequence stars in the cluster. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1711.03154v1-abstract-full').style.display = 'none'; document.getElementById('1711.03154v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 8 November, 2017; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> November 2017. </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">7 pages, 1 figure. To be published in somewhat abbreviated form in the Research Notes of the AAS</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1710.07005">arXiv:1710.07005</a> <span> [<a href="https://arxiv.org/pdf/1710.07005">pdf</a>, <a href="https://arxiv.org/ps/1710.07005">ps</a>, <a href="https://arxiv.org/format/1710.07005">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> <p class="title is-5 mathjax"> A First Transients Survey with JWST: the FLARE project </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Wang%2C+L">Lifan Wang</a>, <a href="/search/astro-ph?searchtype=author&query=Baade%2C+D">D. Baade</a>, <a href="/search/astro-ph?searchtype=author&query=Baron%2C+E">E. Baron</a>, <a href="/search/astro-ph?searchtype=author&query=Bernard%2C+S">S. Bernard</a>, <a href="/search/astro-ph?searchtype=author&query=Bromm%2C+V">V. Bromm</a>, <a href="/search/astro-ph?searchtype=author&query=Brown%2C+P">P. Brown</a>, <a href="/search/astro-ph?searchtype=author&query=Clayton%2C+G">G. Clayton</a>, <a href="/search/astro-ph?searchtype=author&query=Cooke%2C+J">J. Cooke</a>, <a href="/search/astro-ph?searchtype=author&query=Croton%2C+D">D. Croton</a>, <a href="/search/astro-ph?searchtype=author&query=Curtin%2C+C">C. Curtin</a>, <a href="/search/astro-ph?searchtype=author&query=Drout%2C+M">M. Drout</a>, <a href="/search/astro-ph?searchtype=author&query=Doi%2C+M">M. Doi</a>, <a href="/search/astro-ph?searchtype=author&query=Dominguez%2C+I">I. Dominguez</a>, <a href="/search/astro-ph?searchtype=author&query=Finkelstein%2C+S">S. Finkelstein</a>, <a href="/search/astro-ph?searchtype=author&query=Gal-Yam%2C+A">A. Gal-Yam</a>, <a href="/search/astro-ph?searchtype=author&query=Geil%2C+P">P. Geil</a>, <a href="/search/astro-ph?searchtype=author&query=Heger%2C+A">A. Heger</a>, <a href="/search/astro-ph?searchtype=author&query=Hoeflich%2C+P">P. Hoeflich</a>, <a href="/search/astro-ph?searchtype=author&query=Jian%2C+J">J. Jian</a>, <a href="/search/astro-ph?searchtype=author&query=Krisciunas%2C+K">K. Krisciunas</a>, <a href="/search/astro-ph?searchtype=author&query=Koekemoer%2C+A">A. Koekemoer</a>, <a href="/search/astro-ph?searchtype=author&query=Lunnan%2C+R">R. Lunnan</a>, <a href="/search/astro-ph?searchtype=author&query=Maeda%2C+K">K. Maeda</a>, <a href="/search/astro-ph?searchtype=author&query=Maund%2C+J">J. Maund</a>, <a href="/search/astro-ph?searchtype=author&query=Modjaz%2C+M">M. Modjaz</a> , et al. (21 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="1710.07005v2-abstract-short" style="display: inline;"> JWST was conceived and built to answer one of the most fundamental questions that humans can address empirically: "How did the Universe make its first stars?". Our First Lights At REionization (FLARE) project transforms the quest for the epoch of reionization from the static to the time domain. It targets the complementary question: "What happened to those first stars?". It will be answered by obs… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1710.07005v2-abstract-full').style.display = 'inline'; document.getElementById('1710.07005v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1710.07005v2-abstract-full" style="display: none;"> JWST was conceived and built to answer one of the most fundamental questions that humans can address empirically: "How did the Universe make its first stars?". Our First Lights At REionization (FLARE) project transforms the quest for the epoch of reionization from the static to the time domain. It targets the complementary question: "What happened to those first stars?". It will be answered by observations of the most luminous events: supernovae and accretion on to black holes formed by direct collapse from the primordial gas clouds. These transients provide direct constraints on star-formation rates (SFRs) and the truly initial Initial Mass Function (IMF), and they may identify possible stellar seeds of supermassive black holes (SMBHs). Furthermore, our knowledge of the physics of these events at ultra-low metallicity will be much expanded. JWST's unique capabilities will detect these most luminous and earliest cosmic messengers easily in fairly shallow observations. However, these events are very rare at the dawn of cosmic structure formation and so require large area coverage. Time domain astronomy can be advanced to an unprecedented depth by means of a shallow field of JWST reaching 27 mag AB in 2 and 4.4 microns over a field as large as 0.1 square degree visited multiple times each year. Such a survey may set strong constraints or detect massive Pop III SNe at redshifts beyond 10, pinpointing the redshift of the first stars, or at least their death. Based on our current knowledge of superluminous supernovae (SLSNe), such a survey will find one or more SLSNe at redshifts above 6 in five years and possibly several direct collapse black holes. Although JWST is not designed as a wide field survey telescope, we show that such a wide field survey is possible with JWST and is critical in addressing several of its key scientific goals. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1710.07005v2-abstract-full').style.display = 'none'; document.getElementById('1710.07005v2-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> 26 November, 2017; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 19 October, 2017; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> October 2017. </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1709.05146">arXiv:1709.05146</a> <span> [<a href="https://arxiv.org/pdf/1709.05146">pdf</a>, <a href="https://arxiv.org/format/1709.05146">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Instrumentation and Methods for Astrophysics">astro-ph.IM</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="High Energy Astrophysical Phenomena">astro-ph.HE</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.3847/1538-3881/aa8df0">10.3847/1538-3881/aa8df0 <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 I: Third Photometry Data Release of Low-Redshift Type Ia Supernovae and Other White Dwarf Explosions </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Krisciunas%2C+K">Kevin Krisciunas</a>, <a href="/search/astro-ph?searchtype=author&query=Contreras%2C+C">Carlos Contreras</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">M. M. Phillips</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=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=Anais%2C+J">Jorge Anais</a>, <a href="/search/astro-ph?searchtype=author&query=Boldt%2C+L">Luis Boldt</a>, <a href="/search/astro-ph?searchtype=author&query=Busta%2C+L">Luis Busta</a>, <a href="/search/astro-ph?searchtype=author&query=Campillay%2C+A">Abdo Campillay</a>, <a href="/search/astro-ph?searchtype=author&query=Castellon%2C+S">Sergio Castellon</a>, <a href="/search/astro-ph?searchtype=author&query=Folatelli%2C+G">Gaston 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=Gonzalez%2C+C">Consuelo Gonzalez</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=Krzeminski%2C+W">Wojtek Krzeminski</a>, <a href="/search/astro-ph?searchtype=author&query=Persson%2C+S+E">Sven Eric Persson</a>, <a href="/search/astro-ph?searchtype=author&query=Roth%2C+M">Miguel Roth</a>, <a href="/search/astro-ph?searchtype=author&query=Salgado%2C+F">Francisco Salgado</a>, <a href="/search/astro-ph?searchtype=author&query=Seron%2C+J">Jacqueline Seron</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=Torres%2C+S">Simon Torres</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=Li%2C+W">Weidong Li</a> , et al. (5 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="1709.05146v3-abstract-short" style="display: inline;"> We present final natural system optical (ugriBV) and near-infrared (YJH) photometry of 134 supernovae (SNe) with probable white dwarf progenitors that were observed in 2004-2009 as part of the first stage of the Carnegie Supernova Project (CSP-I). The sample consists of 123 Type Ia SNe, 5 Type Iax SNe, 2 super-Chandrasekhar SN candidates, 2 Type Ia SNe interacting with circumstellar matter, and 2… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1709.05146v3-abstract-full').style.display = 'inline'; document.getElementById('1709.05146v3-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1709.05146v3-abstract-full" style="display: none;"> We present final natural system optical (ugriBV) and near-infrared (YJH) photometry of 134 supernovae (SNe) with probable white dwarf progenitors that were observed in 2004-2009 as part of the first stage of the Carnegie Supernova Project (CSP-I). The sample consists of 123 Type Ia SNe, 5 Type Iax SNe, 2 super-Chandrasekhar SN candidates, 2 Type Ia SNe interacting with circumstellar matter, and 2 SN 2006bt-like events. The redshifts of the objects range from z = 0.0037 to 0.0835; the median redshift is 0.0241. For 120 (90%) of these SNe, near-infrared photometry was obtained. Average optical extinction coefficients and color terms are derived and demonstrated to be stable during the five CSP-I observing campaigns. Measurements of the CSP-I near-infrared bandpasses are also described, and near-infrared color terms are estimated through synthetic photometry of stellar atmosphere models. Optical and near-infrared magnitudes of local sequences of tertiary standard stars for each supernova are given, and a new calibration of Y-band magnitudes of the Persson et al. (1998) standards in the CSP-I natural system is presented. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1709.05146v3-abstract-full').style.display = 'none'; document.getElementById('1709.05146v3-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 7 November, 2017; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 15 September, 2017; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> September 2017. </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">95 pages, 50 figures, published in Astronomical Journal, vol. 154, article 211 (November 2017). The full online version contains 114 more finder charts and 119 more light curve plots. Version 2 of this preprint has an updated Table 3, additional references, and two updated light curve plots. Version 3 has updated Table 4</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1709.02487">arXiv:1709.02487</a> <span> [<a href="https://arxiv.org/pdf/1709.02487">pdf</a>, <a href="https://arxiv.org/format/1709.02487">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/aa8f52">10.3847/1538-4357/aa8f52 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Type II supernova spectral diversity I: Observations, sample characterization and spectral line evolution </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Guti%C3%A9rrez%2C+C+P">Claudia P. Guti茅rrez</a>, <a href="/search/astro-ph?searchtype=author&query=Anderson%2C+J+P">Joseph P. Anderson</a>, <a href="/search/astro-ph?searchtype=author&query=Hamuy%2C+M">Mario Hamuy</a>, <a href="/search/astro-ph?searchtype=author&query=Morrell%2C+N">Nidia Morrell</a>, <a href="/search/astro-ph?searchtype=author&query=Gonz%C3%A1lez-Gaitan%2C+S">Santiago Gonz谩lez-Gaitan</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=Phillips%2C+M+M">Mark M. Phillips</a>, <a href="/search/astro-ph?searchtype=author&query=Galbany%2C+L">Lluis Galbany</a>, <a href="/search/astro-ph?searchtype=author&query=Folatelli%2C+G">Gast贸n Folatelli</a>, <a href="/search/astro-ph?searchtype=author&query=Dessart%2C+L">Luc Dessart</a>, <a href="/search/astro-ph?searchtype=author&query=Contreras%2C+C">Carlos Contreras</a>, <a href="/search/astro-ph?searchtype=author&query=Della+Valle%2C+M">Massimo Della Valle</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=Hsiao%2C+E+Y">Eric Y. Hsiao</a>, <a href="/search/astro-ph?searchtype=author&query=Krisciunas%2C+K">Kevin Krisciunas</a>, <a href="/search/astro-ph?searchtype=author&query=Madore%2C+B+F">Barry F. Madore</a>, <a href="/search/astro-ph?searchtype=author&query=Maza%2C+J">Jos茅 Maza</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=Prieto%2C+J+L">Jose Luis Prieto</a>, <a href="/search/astro-ph?searchtype=author&query=Gonz%C3%A1lez%2C+L">Luis Gonz谩lez</a>, <a href="/search/astro-ph?searchtype=author&query=Cappellaro%2C+E">Enrico Cappellaro</a>, <a href="/search/astro-ph?searchtype=author&query=Navarrete%2C+M">Mauricio Navarrete</a>, <a href="/search/astro-ph?searchtype=author&query=Pizzella%2C+A">Alessandro Pizzella</a>, <a href="/search/astro-ph?searchtype=author&query=Ruiz%2C+M+T">Maria T. Ruiz</a>, <a href="/search/astro-ph?searchtype=author&query=Smith%2C+R+C">R. Chris Smith</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="1709.02487v1-abstract-short" style="display: inline;"> We present 888 visual-wavelength spectra of 122 nearby type II supernovae (SNe II) obtained between 1986 and 2009, and ranging between 3 and 363 days post explosion. In this first paper, we outline our observations and data reduction techniques, together with a characterization based on the spectral diversity of SNe~II. A statistical analysis of the spectral matching technique is discussed as an a… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1709.02487v1-abstract-full').style.display = 'inline'; document.getElementById('1709.02487v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1709.02487v1-abstract-full" style="display: none;"> We present 888 visual-wavelength spectra of 122 nearby type II supernovae (SNe II) obtained between 1986 and 2009, and ranging between 3 and 363 days post explosion. In this first paper, we outline our observations and data reduction techniques, together with a characterization based on the spectral diversity of SNe~II. A statistical analysis of the spectral matching technique is discussed as an alternative to non-detection constraints for estimating SN explosion epochs. The time evolution of spectral lines is presented and analysed in terms of how this differs for SNe of different photometric, spectral, and environmental properties: velocities, pseudo-equivalent widths, decline rates, magnitudes, time durations, and environment metallicity. Our sample displays a large range in ejecta expansion velocities, from $\sim9600$ to $\sim1500$ km s$^{-1}$ at 50 days post explosion with a median H$_伪$ value of 7300 km s$^{-1}$. This is most likely explained through differing explosion energies. Significant diversity is also observed in the absolute strength of spectral lines, characterised through their pseudo-equivalent widths. This implies significant diversity in both temperature evolution (linked to progenitor radius) and progenitor metallicity between different SNe~II. Around 60\% of our sample show an extra absorption component on the blue side of the H$_伪$ P-Cygni profile ("Cachito" feature) between 7 and 120 days since explosion. Studying the nature of Cachito, we conclude that these features at early times (before $\sim35$ days) are associated with \ion{Si}{2} $\lambda6355$, while past the middle of the plateau phase they are related to high velocity (HV) features of hydrogen lines. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1709.02487v1-abstract-full').style.display = 'none'; document.getElementById('1709.02487v1-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, 2017; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> September 2017. </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. 112 pages, 153 figures, 9 tables</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1707.07616">arXiv:1707.07616</a> <span> [<a href="https://arxiv.org/pdf/1707.07616">pdf</a>, <a href="https://arxiv.org/format/1707.07616">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/10.1051/0004-6361/201730842">10.1051/0004-6361/201730842 <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 I: photometry data release of low-redshift stripped-envelope supernovae </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Stritzinger%2C+M+D">M. D. 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=Contreras%2C+C">C. Contreras</a>, <a href="/search/astro-ph?searchtype=author&query=Heinrich-Josties%2C+E">E. Heinrich-Josties</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=Anais%2C+J">J. Anais</a>, <a href="/search/astro-ph?searchtype=author&query=Boldt%2C+L">L. Boldt</a>, <a href="/search/astro-ph?searchtype=author&query=Busta%2C+L">L. Busta</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=Campillay%2C+A">A. Campillay</a>, <a href="/search/astro-ph?searchtype=author&query=Corco%2C+C">C. Corco</a>, <a href="/search/astro-ph?searchtype=author&query=Castellon%2C+S">S. Castellon</a>, <a href="/search/astro-ph?searchtype=author&query=Folatelli%2C+G">G. Folatelli</a>, <a href="/search/astro-ph?searchtype=author&query=Gonz%C3%A1lez%2C+C">C. Gonz谩lez</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=Krzeminski%2C+W">W. Krzeminski</a>, <a href="/search/astro-ph?searchtype=author&query=Salgado%2C+F">F. Salgado</a>, <a href="/search/astro-ph?searchtype=author&query=Ser%C3%B3n%2C+J">J. Ser贸n</a>, <a href="/search/astro-ph?searchtype=author&query=Torres-Robledo%2C+S">S. Torres-Robledo</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=Hamuy%2C+M">M. Hamuy</a>, <a href="/search/astro-ph?searchtype=author&query=Krisciunas%2C+K">K. Krisciunas</a>, <a href="/search/astro-ph?searchtype=author&query=Madore%2C+B+F">B. F. Madore</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="1707.07616v2-abstract-short" style="display: inline;"> The first phase of the Carnegie Supernova Project (CSP-I) was a dedicated supernova follow-up program based at the Las Campanas Observatory that collected science data of young, low-redshift supernovae between 2004 and 2009. Presented in this paper is the CSP-I photometric data release of low-redshift stripped-envelope core-collapse supernovae. The data consist of optical (uBgVri) photometry of 34… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1707.07616v2-abstract-full').style.display = 'inline'; document.getElementById('1707.07616v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1707.07616v2-abstract-full" style="display: none;"> The first phase of the Carnegie Supernova Project (CSP-I) was a dedicated supernova follow-up program based at the Las Campanas Observatory that collected science data of young, low-redshift supernovae between 2004 and 2009. Presented in this paper is the CSP-I photometric data release of low-redshift stripped-envelope core-collapse supernovae. The data consist of optical (uBgVri) photometry of 34 objects, with a subset of 26 having near-infrared (YJH) photometry. Twenty objects have optical pre-maximum coverage with a subset of 12 beginning at least five days prior to the epoch of B-band maximum brightness. In the near-infrared, 17 objects have pre-maximum observations with a subset of 14 beginning at least five days prior to the epoch of J-band maximum brightness. Analysis of this photometric data release is presented in companion papers focusing on techniques to estimate host-galaxy extinction (Stritzinger et al., submitted) and the light-curve and progenitor star properties of the sample (Taddia et al., submitted). The analysis of an accompanying visual-wavelength spectroscopy sample of ~150 spectra will be the subject of a future paper. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1707.07616v2-abstract-full').style.display = 'none'; document.getElementById('1707.07616v2-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 August, 2017; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 20 July, 2017; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> July 2017. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">Updated a couple of small errors</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> A&A 609, A134 (2018) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1707.05350">arXiv:1707.05350</a> <span> [<a href="https://arxiv.org/pdf/1707.05350">pdf</a>, <a href="https://arxiv.org/format/1707.05350">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/aa84b2">10.3847/1538-4357/aa84b2 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Light and color curve properties of type Ia supernovae: Theory vs. Observations </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=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=Burns%2C+C+R">C. R. Burns</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=Phillips%2C+M+M">M. M. Phillips</a>, <a href="/search/astro-ph?searchtype=author&query=Sand%2C+D">D. Sand</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">N. Suntzeff</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=Wang%2C+L">L. Wang</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="1707.05350v2-abstract-short" style="display: inline;"> We study optical light curve(LC) relations of type Ia supernovae(SNe~Ia) for their use in cosmology using high-quality photometry published by the Carnegie-Supernovae-Project (CSP-I). We revisit the classical luminosity-decline-rate ($螖m_{15}$) relation and the Lira-relation, as well as investigate the time evolution of the ($B-V$) color and $B(B-V)$, which serves as the basis of the color-stretch… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1707.05350v2-abstract-full').style.display = 'inline'; document.getElementById('1707.05350v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1707.05350v2-abstract-full" style="display: none;"> We study optical light curve(LC) relations of type Ia supernovae(SNe~Ia) for their use in cosmology using high-quality photometry published by the Carnegie-Supernovae-Project (CSP-I). We revisit the classical luminosity-decline-rate ($螖m_{15}$) relation and the Lira-relation, as well as investigate the time evolution of the ($B-V$) color and $B(B-V)$, which serves as the basis of the color-stretch relation and Color-MAGnitude-Intercept-Calibrations(CMAGIC). Our analysis is based on explosion and radiation transport simulations for spherically-symmetric delayed-detonation models(DDT) producing normal-bright and subluminous SNe~Ia. Empirical LC-relations can be understood as having the same physical underpinnings: i.e. the opacities, ionization balances in the photosphere, and radioactive energy deposition changing with time from below to above the photosphere. Some 3-4 weeks past maximum, the photosphere recedes to ${}^{56}$Ni-rich layers of similar density structure, leading to a similar color evolution. An important secondary parameter is the central density $蟻_c$ of the WD because at higher densities more electron capture elements are produced at the expense of ${}^{56}$Ni production. This results in a $螖m_{15}$ spread of 0.1 mag for normal-bright and 0.7 mag in sub-luminous SNe~Ia and $\approx0.2$ mag in the Lira-relation. We show why color-magnitude diagrams emphasize the transition between physical regimes, and allow to construct templates depend mostly on $螖m_{15}$ with little dispersion in both the CSP-I sample and our DDT-models. This allows to separate intrinsic SN~Ia variations from the interstellar reddening characterized by $E(B-V)$ and $R_{B}$. Mixing of different explosion scenarios causes a wide spread in empirical relations which may suggest one dominant scenario. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1707.05350v2-abstract-full').style.display = 'none'; document.getElementById('1707.05350v2-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 8 August, 2017; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 17 July, 2017; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> July 2017. </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">49 pages, 17 figures, 3 tables accepted (Original Version: 03/29/2017; revised: 6/30/2017; accepted: 8/4/2017)</span> </p> </li> </ol> <nav class="pagination is-small is-centered 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