Search | arXiv e-print repository

<!DOCTYPE html> <html lang="en"> <head> <meta charset="utf-8"/> <meta name="viewport" content="width=device-width, initial-scale=1"/>  <link rel="apple-touch-icon" sizes="180x180" href="https://static.arxiv.org/static/base/1.0.0a5/images/icons/apple-touch-icon.png"> <link rel="icon" type="image/png" sizes="32x32" href="https://static.arxiv.org/static/base/1.0.0a5/images/icons/favicon-32x32.png"> <link rel="icon" type="image/png" sizes="16x16" href="https://static.arxiv.org/static/base/1.0.0a5/images/icons/favicon-16x16.png"> <link rel="manifest" href="https://static.arxiv.org/static/base/1.0.0a5/images/icons/site.webmanifest"> <link rel="mask-icon" href="https://static.arxiv.org/static/base/1.0.0a5/images/icons/safari-pinned-tab.svg" color="#b31b1b"> <link rel="shortcut icon" href="https://static.arxiv.org/static/base/1.0.0a5/images/icons/favicon.ico"> <meta name="msapplication-TileColor" content="#b31b1b"> <meta name="msapplication-config" content="images/icons/browserconfig.xml"> <meta name="theme-color" content="#b31b1b">  <title>Search | arXiv e-print repository</title> <script defer src="https://static.arxiv.org/static/base/1.0.0a5/fontawesome-free-5.11.2-web/js/all.js"></script> <link rel="stylesheet" href="https://static.arxiv.org/static/base/1.0.0a5/css/arxivstyle.css" /> <script type="text/x-mathjax-config"> MathJax.Hub.Config({ messageStyle: "none", extensions: ["tex2jax.js"], jax: ["input/TeX", "output/HTML-CSS"], tex2jax: { inlineMath: [ ['$','$'], ["\$","\$"] ], displayMath: [ ['$$','$$'], ["\\[","\\]"] ], processEscapes: true, ignoreClass: '.*', processClass: 'mathjax.*' }, TeX: { extensions: ["AMSmath.js", "AMSsymbols.js", "noErrors.js"], noErrors: { inlineDelimiters: ["$","$"], multiLine: false, style: { "font-size": "normal", "border": "" } } }, "HTML-CSS": { availableFonts: ["TeX"] } }); </script> <script src='//static.arxiv.org/MathJax-2.7.3/MathJax.js'></script> <script src="https://static.arxiv.org/static/base/1.0.0a5/js/notification.js"></script> <link rel="stylesheet" href="https://static.arxiv.org/static/search/0.5.6/css/bulma-tooltip.min.css" /> <link rel="stylesheet" href="https://static.arxiv.org/static/search/0.5.6/css/search.css" /> <script src="https://code.jquery.com/jquery-3.2.1.slim.min.js" integrity="sha256-k2WSCIexGzOj3Euiig+TlR8gA0EmPjuc79OEeY5L45g=" crossorigin="anonymous"></script> <script src="https://static.arxiv.org/static/search/0.5.6/js/fieldset.js"></script> <style> radio#cf-customfield_11400 { display: none; } </style> </head> <body> <header><a href="#main-container" class="is-sr-only">Skip to main content</a>  <div class="attribution level is-marginless" role="banner"> <div class="level-left"> <a class="level-item" href="https://cornell.edu/"><img src="https://static.arxiv.org/static/base/1.0.0a5/images/cornell-reduced-white-SMALL.svg" alt="Cornell University" width="200" aria-label="logo" /></a> </div> <div class="level-right is-marginless"><p class="sponsors level-item is-marginless"><span id="support-ack-url">We gratefully acknowledge support from<br /> the Simons Foundation, <a href="https://info.arxiv.org/about/ourmembers.html">member institutions</a>, and all contributors. <a href="https://info.arxiv.org/about/donate.html">Donate</a></span></p></div> </div>  <div class="identity level is-marginless"> <div class="level-left"> <div class="level-item"> <a class="arxiv" href="https://arxiv.org/" aria-label="arxiv-logo"> <img src="https://static.arxiv.org/static/base/1.0.0a5/images/arxiv-logo-one-color-white.svg" aria-label="logo" alt="arxiv logo" width="85" style="width:85px;"/> </a> </div> </div> <div class="search-block level-right"> <form class="level-item mini-search" method="GET" action="https://arxiv.org/search"> <div class="field has-addons"> <div class="control"> <input class="input is-small" type="text" name="query" placeholder="Search..." aria-label="Search term or terms" /> <p class="help"><a href="https://info.arxiv.org/help">Help</a> | <a href="https://arxiv.org/search/advanced">Advanced Search</a></p> </div> <div class="control"> <div class="select is-small"> <select name="searchtype" aria-label="Field to search"> <option value="all" selected="selected">All fields</option> <option value="title">Title</option> <option value="author">Author</option> <option value="abstract">Abstract</option> <option value="comments">Comments</option> <option value="journal_ref">Journal reference</option> <option value="acm_class">ACM classification</option> <option value="msc_class">MSC classification</option> <option value="report_num">Report number</option> <option value="paper_id">arXiv identifier</option> <option value="doi">DOI</option> <option value="orcid">ORCID</option> <option value="author_id">arXiv author ID</option> <option value="help">Help pages</option> <option value="full_text">Full text</option> </select> </div> </div> <input type="hidden" name="source" value="header"> <button class="button is-small is-cul-darker">Search</button> </div> </form> </div> </div>  <div class="container"> <div class="user-tools is-size-7 has-text-right has-text-weight-bold" role="navigation" aria-label="User menu"> <a href="https://arxiv.org/login">Login</a> </div> </div> </header> <main class="container" id="main-container"> <div class="level is-marginless"> <div class="level-left"> <h1 class="title is-clearfix"> Showing 1–50 of 115 results for author: <span class="mathjax">Bhalerao, V</span> </h1> </div> <div class="level-right is-hidden-mobile">  <span class="help" style="display: inline-block;"><a href="https://github.com/arXiv/arxiv-search/releases">Search v0.5.6 released 2020-02-24</a>  </span> </div> </div> <div class="content"> <form method="GET" action="/search/astro-ph" aria-role="search"> Searching in archive <strong>astro-ph</strong>. <a href="/search/?searchtype=author&query=Bhalerao%2C+V">Search in all archives.</a> <div class="field has-addons-tablet"> <div class="control is-expanded"> <label for="query" class="hidden-label">Search term or terms</label> <input class="input is-medium" id="query" name="query" placeholder="Search term..." type="text" value="Bhalerao, V"> </div> <div class="select control is-medium"> <label class="is-hidden" for="searchtype">Field</label> <select class="is-medium" id="searchtype" name="searchtype"><option value="all">All fields</option><option value="title">Title</option><option selected value="author">Author(s)</option><option value="abstract">Abstract</option><option value="comments">Comments</option><option value="journal_ref">Journal reference</option><option value="acm_class">ACM classification</option><option value="msc_class">MSC classification</option><option value="report_num">Report number</option><option value="paper_id">arXiv identifier</option><option value="doi">DOI</option><option value="orcid">ORCID</option><option value="license">License (URI)</option><option value="author_id">arXiv author ID</option><option value="help">Help pages</option><option value="full_text">Full text</option></select> </div> <div class="control"> <button class="button is-link is-medium">Search</button> </div> </div> <div class="field"> <div class="control is-size-7"> <label class="radio"> <input checked id="abstracts-0" name="abstracts" type="radio" value="show"> Show abstracts </label> <label class="radio"> <input id="abstracts-1" name="abstracts" type="radio" value="hide"> Hide abstracts </label> </div> </div> <div class="is-clearfix" style="height: 2.5em"> <div class="is-pulled-right"> <a href="/search/advanced?terms-0-term=Bhalerao%2C+V&terms-0-field=author&size=50&order=-announced_date_first">Advanced Search</a> </div> </div> <input type="hidden" name="order" value="-announced_date_first"> <input type="hidden" name="size" value="50"> </form> <div class="level breathe-horizontal"> <div class="level-left"> <form method="GET" action="/search/"> <div style="display: none;"> <select id="searchtype" name="searchtype"><option value="all">All fields</option><option value="title">Title</option><option selected value="author">Author(s)</option><option value="abstract">Abstract</option><option value="comments">Comments</option><option value="journal_ref">Journal reference</option><option value="acm_class">ACM classification</option><option value="msc_class">MSC classification</option><option value="report_num">Report number</option><option value="paper_id">arXiv identifier</option><option value="doi">DOI</option><option value="orcid">ORCID</option><option value="license">License (URI)</option><option value="author_id">arXiv author ID</option><option value="help">Help pages</option><option value="full_text">Full text</option></select> <input id="query" name="query" type="text" value="Bhalerao, V"> <ul id="abstracts"><li><input checked id="abstracts-0" name="abstracts" type="radio" value="show"> <label for="abstracts-0">Show abstracts</label></li><li><input id="abstracts-1" name="abstracts" type="radio" value="hide"> <label for="abstracts-1">Hide abstracts</label></li></ul> </div> <div class="box field is-grouped is-grouped-multiline level-item"> <div class="control"> <span class="select is-small"> <select id="size" name="size"><option value="25">25</option><option selected value="50">50</option><option value="100">100</option><option value="200">200</option></select> </span> <label for="size">results per page</label>. </div> <div class="control"> <label for="order">Sort results by</label> <span class="select is-small"> <select id="order" name="order"><option selected value="-announced_date_first">Announcement date (newest first)</option><option value="announced_date_first">Announcement date (oldest first)</option><option value="-submitted_date">Submission date (newest first)</option><option value="submitted_date">Submission date (oldest first)</option><option value="">Relevance</option></select> </span> </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=Bhalerao%2C+V&start=50" class="pagination-next" >Next </a> <ul class="pagination-list"> <li> <a href="/search/?searchtype=author&query=Bhalerao%2C+V&start=0" class="pagination-link is-current" aria-label="Goto page 1">1 </a> </li> <li> <a href="/search/?searchtype=author&query=Bhalerao%2C+V&start=50" class="pagination-link " aria-label="Page 2" aria-current="page">2 </a> </li> <li> <a href="/search/?searchtype=author&query=Bhalerao%2C+V&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/2411.18215">arXiv:2411.18215</a> <span> [<a href="https://arxiv.org/pdf/2411.18215">pdf</a>, <a href="https://arxiv.org/format/2411.18215">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"> Discovery and Detailed Study of the M31 Classical Nova AT 2023tkw: Evidence for Internal Shocks </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Basu%2C+J">Judhajeet Basu</a>, <a href="/search/astro-ph?searchtype=author&query=Kumar%2C+R">Ravi Kumar</a>, <a href="/search/astro-ph?searchtype=author&query=Anupama%2C+G+C">G. C. Anupama</a>, <a href="/search/astro-ph?searchtype=author&query=Barway%2C+S">Sudhanshu Barway</a>, <a href="/search/astro-ph?searchtype=author&query=Hauschildt%2C+P+H">Peter H. Hauschildt</a>, <a href="/search/astro-ph?searchtype=author&query=Chamoli%2C+S">Shatakshi Chamoli</a>, <a href="/search/astro-ph?searchtype=author&query=Swain%2C+V">Vishwajeet Swain</a>, <a href="/search/astro-ph?searchtype=author&query=Bhalerao%2C+V">Varun Bhalerao</a>, <a href="/search/astro-ph?searchtype=author&query=Karambelkar%2C+V+R">Viraj R. Karambelkar</a>, <a href="/search/astro-ph?searchtype=author&query=Kasliwal%2C+M+M">Mansi M. Kasliwal</a>, <a href="/search/astro-ph?searchtype=author&query=Das%2C+K+K">Kaustav K. Das</a>, <a href="/search/astro-ph?searchtype=author&query=Andreoni%2C+I">Igor Andreoni</a>, <a href="/search/astro-ph?searchtype=author&query=Singh%2C+A">Avinash Singh</a>, <a href="/search/astro-ph?searchtype=author&query=Teja%2C+R+S">Rishabh S. Teja</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="2411.18215v1-abstract-short" style="display: inline;"> We present a detailed analysis of a slow classical nova in M31 exhibiting multiple peaks in its light curve. Spectroscopic and photometric observations were used to investigate the underlying physical processes. Shock-induced heating events resulting in the expansion and contraction of the photosphere are likely responsible for the observed multiple peaks. Deviation of the observed spectrum at the… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2411.18215v1-abstract-full').style.display = 'inline'; document.getElementById('2411.18215v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2411.18215v1-abstract-full" style="display: none;"> We present a detailed analysis of a slow classical nova in M31 exhibiting multiple peaks in its light curve. Spectroscopic and photometric observations were used to investigate the underlying physical processes. Shock-induced heating events resulting in the expansion and contraction of the photosphere are likely responsible for the observed multiple peaks. Deviation of the observed spectrum at the peak from the models also suggests the presence of shocks. The successive peaks occurring at increasing intervals could be due to the series of internal shocks generated near or within the photosphere. Spectral modeling suggests a low-mass white dwarf accreting slowly from a companion star. The ejecta mass, estimated from spectral analysis, is $\sim 10^{-4}\mathrm{M_{\odot}}$, which is typical for a slow nova. We estimate the binary, by comparing the archival HST data and eruption properties with stellar and novae models, to comprise a 0.65 $\mathrm{M_{\odot}}$ primary white dwarf and a K III cool giant secondary star. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2411.18215v1-abstract-full').style.display = 'none'; document.getElementById('2411.18215v1-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 November, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> November 2024. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">15 pages, 5 figures, 3 tables. Submitted to ApJ. Comments are 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/2411.00410">arXiv:2411.00410</a> <span> [<a href="https://arxiv.org/pdf/2411.00410">pdf</a>, <a href="https://arxiv.org/format/2411.00410">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="High Energy Astrophysical Phenomena">astro-ph.HE</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Instrumentation and Methods for Astrophysics">astro-ph.IM</span> </div> </div> <p class="title is-5 mathjax"> Investigating Polarization characteristics of GRB200503A and GRB201009A </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Saraogi%2C+D">Divita Saraogi</a>, <a href="/search/astro-ph?searchtype=author&query=Bala%2C+S">Suman Bala</a>, <a href="/search/astro-ph?searchtype=author&query=Joshi%2C+J">Jitendra Joshi</a>, <a href="/search/astro-ph?searchtype=author&query=Iyyani%2C+S">Shabnam Iyyani</a>, <a href="/search/astro-ph?searchtype=author&query=Bhalerao%2C+V">Varun Bhalerao</a>, <a href="/search/astro-ph?searchtype=author&query=Aditya%2C+J+V">J Venkata Aditya</a>, <a href="/search/astro-ph?searchtype=author&query=Svinkin%2C+D+S">D. S. Svinkin</a>, <a href="/search/astro-ph?searchtype=author&query=Frederiks%2C+D+D">D. D. Frederiks</a>, <a href="/search/astro-ph?searchtype=author&query=Lysenko%2C+A+L">A. L. Lysenko</a>, <a href="/search/astro-ph?searchtype=author&query=Ridnaia%2C+A+V">A. V. Ridnaia</a>, <a href="/search/astro-ph?searchtype=author&query=Kozyrev%2C+A+S">A. S. Kozyrev</a>, <a href="/search/astro-ph?searchtype=author&query=Golovin%2C+D+V">D. V. Golovin</a>, <a href="/search/astro-ph?searchtype=author&query=Mitrofanov%2C+I+G">I. G. Mitrofanov</a>, <a href="/search/astro-ph?searchtype=author&query=Litvak%2C+M+L">M. L. Litvak</a>, <a href="/search/astro-ph?searchtype=author&query=Sanin%2C+A+B">A. B. Sanin</a>, <a href="/search/astro-ph?searchtype=author&query=Chattopadyay%2C+T">Tanmoy Chattopadyay</a>, <a href="/search/astro-ph?searchtype=author&query=Gupta%2C+S">Soumya Gupta</a>, <a href="/search/astro-ph?searchtype=author&query=Waratkar%2C+G">Gaurav Waratkar</a>, <a href="/search/astro-ph?searchtype=author&query=Bhattacharya%2C+D">Dipankar Bhattacharya</a>, <a href="/search/astro-ph?searchtype=author&query=Vadawal%2C+S">Santosh Vadawal</a>, <a href="/search/astro-ph?searchtype=author&query=Dewangan%2C+G">Gulab Dewangan</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="2411.00410v1-abstract-short" style="display: inline;"> We present results of a comprehensive analysis of the polarization characteristics of GRB 200503A and GRB 201009A observed with the Cadmium Zinc Telluride Imager (CZTI) on board AstroSat. Despite these GRBs being reasonably bright, they were missed by several spacecraft and had thus far not been localized well, hindering polarization analysis. We present positions of these bursts obtained from the… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2411.00410v1-abstract-full').style.display = 'inline'; document.getElementById('2411.00410v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2411.00410v1-abstract-full" style="display: none;"> We present results of a comprehensive analysis of the polarization characteristics of GRB 200503A and GRB 201009A observed with the Cadmium Zinc Telluride Imager (CZTI) on board AstroSat. Despite these GRBs being reasonably bright, they were missed by several spacecraft and had thus far not been localized well, hindering polarization analysis. We present positions of these bursts obtained from the Inter-Planetary Network (IPN) and the newly developed CZTI localization pipeline. We then undertook polarization analyses using the standard CZTI pipeline. We cannot constrain the polarization properties for GRB 200503A, but find that GRB 201009A has a high degree of polarization. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2411.00410v1-abstract-full').style.display = 'none'; document.getElementById('2411.00410v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 1 November, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> November 2024. </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2409.15263">arXiv:2409.15263</a> <span> [<a href="https://arxiv.org/pdf/2409.15263">pdf</a>, <a href="https://arxiv.org/format/2409.15263">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="Instrumentation and Methods for Astrophysics">astro-ph.IM</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Artificial Intelligence">cs.AI</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Machine Learning">cs.LG</span> </div> </div> <p class="title is-5 mathjax"> The Palomar twilight survey of 'Ayl贸'chaxnim, Atiras, and comets </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Bolin%2C+B+T">B. T. Bolin</a>, <a href="/search/astro-ph?searchtype=author&query=Masci%2C+F+J">F. J. Masci</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=Duev%2C+D+A">D. A. Duev</a>, <a href="/search/astro-ph?searchtype=author&query=Ivezi%C4%87%2C+%C5%BD">沤. Ivezi膰</a>, <a href="/search/astro-ph?searchtype=author&query=Jones%2C+R+L">R. L. Jones</a>, <a href="/search/astro-ph?searchtype=author&query=Yoachim%2C+P">P. Yoachim</a>, <a href="/search/astro-ph?searchtype=author&query=Ahumada%2C+T">T. Ahumada</a>, <a href="/search/astro-ph?searchtype=author&query=Bhalerao%2C+V">V. Bhalerao</a>, <a href="/search/astro-ph?searchtype=author&query=Choudhary%2C+H">H. Choudhary</a>, <a href="/search/astro-ph?searchtype=author&query=Contreras%2C+C">C. Contreras</a>, <a href="/search/astro-ph?searchtype=author&query=Cheng%2C+Y+-">Y. -C. Cheng</a>, <a href="/search/astro-ph?searchtype=author&query=Copperwheat%2C+C+M">C. M. Copperwheat</a>, <a href="/search/astro-ph?searchtype=author&query=Deshmukh%2C+K">K. Deshmukh</a>, <a href="/search/astro-ph?searchtype=author&query=Fremling%2C+C">C. Fremling</a>, <a href="/search/astro-ph?searchtype=author&query=Granvik%2C+M">M. Granvik</a>, <a href="/search/astro-ph?searchtype=author&query=Hardegree-Ullman%2C+K+K">K. K. Hardegree-Ullman</a>, <a href="/search/astro-ph?searchtype=author&query=Ho%2C+A+Y+Q">A. Y. Q. Ho</a>, <a href="/search/astro-ph?searchtype=author&query=Jedicke%2C+R">R. Jedicke</a>, <a href="/search/astro-ph?searchtype=author&query=Kasliwal%2C+M">M. Kasliwal</a>, <a href="/search/astro-ph?searchtype=author&query=Kumar%2C+H">H. Kumar</a>, <a href="/search/astro-ph?searchtype=author&query=Lin%2C+Z+-">Z. -Y. Lin</a>, <a href="/search/astro-ph?searchtype=author&query=Mahabal%2C+A">A. Mahabal</a>, <a href="/search/astro-ph?searchtype=author&query=Monson%2C+A">A. Monson</a>, <a href="/search/astro-ph?searchtype=author&query=Neill%2C+J+D">J. D. Neill</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="2409.15263v1-abstract-short" style="display: inline;"> Near-sun sky twilight observations allow for the detection of asteroid interior to the orbit of Venus (Aylos), the Earth (Atiras), and comets. We present the results of observations with the Palomar 48-inch telescope (P48)/Zwicky Transient Facility (ZTF) camera in 30 s r-band exposures taken during evening astronomical twilight from 2019 Sep 20 to 2022 March 7 and during morning astronomical twili… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2409.15263v1-abstract-full').style.display = 'inline'; document.getElementById('2409.15263v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2409.15263v1-abstract-full" style="display: none;"> Near-sun sky twilight observations allow for the detection of asteroid interior to the orbit of Venus (Aylos), the Earth (Atiras), and comets. We present the results of observations with the Palomar 48-inch telescope (P48)/Zwicky Transient Facility (ZTF) camera in 30 s r-band exposures taken during evening astronomical twilight from 2019 Sep 20 to 2022 March 7 and during morning astronomical twilight sky from 2019 Sep 21 to 2022 Sep 29. More than 46,000 exposures were taken in evening and morning astronomical twilight within 31 to 66 degrees from the Sun with an r-band limiting magnitude between 18.1 and 20.9. The twilight pointings show a slight seasonal dependence in limiting magnitude and ability to point closer towards the Sun, with limiting magnitude slightly improving during summer. In total, the one Aylo, (594913) 'Ayl贸'chaxnim, and 4 Atiras, 2020 OV1, 2021 BS1, 2021 PB2, and 2021 VR3, were discovered in evening and morning twilight observations. Additional twilight survey discoveries also include 6 long-period comets: C/2020 T2, C/2020 V2, C/2021 D2, C/2021 E3, C/2022 E3, and C/2022 P3, and two short-period comets: P/2021 N1 and P/2022 P2 using deep learning comet detection pipelines. The P48/ZTF twilight survey also recovered 11 known Atiras, one Aylo, three short-period comes, two long-period comets, and one interstellar object. Lastly, the Vera Rubin Observatory will conduct a twilight survey starting in its first year of operations and will cover the sky within 45 degrees of the Sun. Twilight surveys such as those by ZTF and future surveys will provide opportunities for discovering asteroids inside the orbits of Earth and Venus. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2409.15263v1-abstract-full').style.display = 'none'; document.getElementById('2409.15263v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 23 September, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> September 2024. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">26 pages, 13 figures, 4 tables, accepted for publication in Icarus</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2409.08822">arXiv:2409.08822</a> <span> [<a href="https://arxiv.org/pdf/2409.08822">pdf</a>, <a href="https://arxiv.org/format/2409.08822">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"> Development of a Compton Imager Setup </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Arya%2C+A">Anuraag Arya</a>, <a href="/search/astro-ph?searchtype=author&query=Bilkhu%2C+H+S">Harmanjeet Singh Bilkhu</a>, <a href="/search/astro-ph?searchtype=author&query=Vishwakarma%2C+S">Sandeep Vishwakarma</a>, <a href="/search/astro-ph?searchtype=author&query=Belatikar%2C+H">Hrishikesh Belatikar</a>, <a href="/search/astro-ph?searchtype=author&query=Bhalerao%2C+V">Varun Bhalerao</a>, <a href="/search/astro-ph?searchtype=author&query=Ghodgaonkar%2C+A">Abhijeet Ghodgaonkar</a>, <a href="/search/astro-ph?searchtype=author&query=Koyande%2C+J+G">Jayprakash G. Koyande</a>, <a href="/search/astro-ph?searchtype=author&query=Marathe%2C+A">Aditi Marathe</a>, <a href="/search/astro-ph?searchtype=author&query=Mithun%2C+N+P+S">N. P. S. Mithun</a>, <a href="/search/astro-ph?searchtype=author&query=Narang%2C+S">Sanjoli Narang</a>, <a href="/search/astro-ph?searchtype=author&query=Nimbalkar%2C+S">Sudhanshu Nimbalkar</a>, <a href="/search/astro-ph?searchtype=author&query=Page%2C+P">Pranav Page</a>, <a href="/search/astro-ph?searchtype=author&query=Palit%2C+S">Sourav Palit</a>, <a href="/search/astro-ph?searchtype=author&query=Patel%2C+A">Arpit Patel</a>, <a href="/search/astro-ph?searchtype=author&query=Shetye%2C+A">Amit Shetye</a>, <a href="/search/astro-ph?searchtype=author&query=Tallur%2C+S">Siddharth Tallur</a>, <a href="/search/astro-ph?searchtype=author&query=Tendulkar%2C+S">Shriharsh Tendulkar</a>, <a href="/search/astro-ph?searchtype=author&query=Vadawale%2C+S">Santosh Vadawale</a>, <a href="/search/astro-ph?searchtype=author&query=Waratkar%2C+G">Gaurav Waratkar</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="2409.08822v1-abstract-short" style="display: inline;"> Hard X-ray photons with energies in the range of hundreds of keV typically undergo Compton scattering when they are incident on a detector. In this process, an incident photon deposits a fraction of its energy at the point of incidence and continues onward with a change in direction that depends on the amount of energy deposited. By using a pair of detectors to detect the point of incidence and th… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2409.08822v1-abstract-full').style.display = 'inline'; document.getElementById('2409.08822v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2409.08822v1-abstract-full" style="display: none;"> Hard X-ray photons with energies in the range of hundreds of keV typically undergo Compton scattering when they are incident on a detector. In this process, an incident photon deposits a fraction of its energy at the point of incidence and continues onward with a change in direction that depends on the amount of energy deposited. By using a pair of detectors to detect the point of incidence and the direction of the scattered photon, we can calculate the scattering direction and angle. The position of a source in the sky can be reconstructed using many Compton photon pairs from a source. We demonstrate this principle in the laboratory by using a pair of Cadmium Zinc Telluride detectors sensitive in the energy range of 20-200 keV. The laboratory setup consists of the two detectors placed perpendicular to each other in a lead-lined box. The detectors are read out by a custom-programmed Xilinx PYNQ FPGA board, and data is then transferred to a PC. The detectors are first calibrated using lines from $^{241}\mathrm{Am}$, $^{155}\mathrm{Eu}$ and $^{133}\mathrm{Ba}$ sources. We irradiated the detectors with a collimated $^{133}\mathrm{Ba}$ source and identified Compton scattering events for the 356 keV line. We run a Compton reconstruction algorithm and correctly infer the location of the source in the detector frame. This comprises a successful technology demonstration for a Compton imaging camera in the Hard X-ray regime. We present the details of our setup, the data acquisition process, and software algorithms, and showcase our results. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2409.08822v1-abstract-full').style.display = 'none'; document.getElementById('2409.08822v1-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, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> September 2024. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">17 pages, 10 figures, submitted for publication in Journal of Astronomical Telescopes, Instruments, and Systems (JATIS)</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2407.13207">arXiv:2407.13207</a> <span> [<a href="https://arxiv.org/pdf/2407.13207">pdf</a>, <a href="https://arxiv.org/format/2407.13207">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="High Energy Astrophysical Phenomena">astro-ph.HE</span> </div> </div> <p class="title is-5 mathjax"> SN 2021wvw: A core-collapse supernova at the sub-luminous, slower, and shorter end of Type IIPs </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Teja%2C+R+S">Rishabh Singh Teja</a>, <a href="/search/astro-ph?searchtype=author&query=Goldberg%2C+J+A">Jared A. Goldberg</a>, <a href="/search/astro-ph?searchtype=author&query=Sahu%2C+D+K">D. K. Sahu</a>, <a href="/search/astro-ph?searchtype=author&query=Anupama%2C+G+C">G. C. Anupama</a>, <a href="/search/astro-ph?searchtype=author&query=Singh%2C+A">Avinash Singh</a>, <a href="/search/astro-ph?searchtype=author&query=Swain%2C+V">Vishwajeet Swain</a>, <a href="/search/astro-ph?searchtype=author&query=Bhalerao%2C+V">Varun Bhalerao</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2407.13207v1-abstract-short" style="display: inline;"> We present detailed multi-band photometric and spectroscopic observations and analysis of a rare core-collapse supernova SN 2021wvw, that includes photometric evolution up to 250 d and spectroscopic coverage up to 100 d post-explosion. A unique event that does not fit well within the general trends observed for Type II-P supernovae, SN 2021wvw shows an intermediate luminosity with a short plateau… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2407.13207v1-abstract-full').style.display = 'inline'; document.getElementById('2407.13207v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2407.13207v1-abstract-full" style="display: none;"> We present detailed multi-band photometric and spectroscopic observations and analysis of a rare core-collapse supernova SN 2021wvw, that includes photometric evolution up to 250 d and spectroscopic coverage up to 100 d post-explosion. A unique event that does not fit well within the general trends observed for Type II-P supernovae, SN 2021wvw shows an intermediate luminosity with a short plateau phase of just about 75 d, followed by a very sharp (~10 d) transition to the tail phase. Even in the velocity space, it lies at a lower velocity compared to a larger Type II sample. The observed peak absolute magnitude is -16.1 mag in r-band, and the nickel mass is well constrained to 0.020(6) Msol. Detailed hydrodynamical modeling using MESA+STELLA suggests a radially compact, low-metallicity, high-mass Red Supergiant progenitor (ZAMS mass=18 Msol), which exploded with ~0.2e51 erg/s leaving an ejecta mass of Mej~5 Msol. Significant late-time fallback during the shock propagation phase is also seen in progenitor+explosion models consistent with the light curve properties. As the faintest short-plateau supernova characterized to date, this event adds to the growing diversity of transitional events between the canonical ~100 d plateau Type IIP and stripped-envelope events. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2407.13207v1-abstract-full').style.display = 'none'; document.getElementById('2407.13207v1-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 July, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> July 2024. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">Accepted for publication in the Astrophysical Journal (18 pages, 13 figures, 4 tables)</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2406.13755">arXiv:2406.13755</a> <span> [<a href="https://arxiv.org/pdf/2406.13755">pdf</a>, <a href="https://arxiv.org/format/2406.13755">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/ad5a92">10.3847/1538-4357/ad5a92 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> A detailed time-resolved and energy-resolved spectro-polarimetric study of bright GRBs detected by AstroSat CZTI in its first year of operation </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Gupta%2C+R">Rahul Gupta</a>, <a href="/search/astro-ph?searchtype=author&query=Pandey%2C+S+B">S. B. Pandey</a>, <a href="/search/astro-ph?searchtype=author&query=Gupta%2C+S">S. Gupta</a>, <a href="/search/astro-ph?searchtype=author&query=Chattopadhayay%2C+T">T. Chattopadhayay</a>, <a href="/search/astro-ph?searchtype=author&query=Bhattacharya%2C+D">D. Bhattacharya</a>, <a href="/search/astro-ph?searchtype=author&query=Bhalerao%2C+V">V. Bhalerao</a>, <a href="/search/astro-ph?searchtype=author&query=Castro-Tirado%2C+A+J">A. J. Castro-Tirado</a>, <a href="/search/astro-ph?searchtype=author&query=Valeev%2C+A">A. Valeev</a>, <a href="/search/astro-ph?searchtype=author&query=Ror%2C+A+K">A. K. Ror</a>, <a href="/search/astro-ph?searchtype=author&query=Sharma%2C+V">V. Sharma</a>, <a href="/search/astro-ph?searchtype=author&query=Racusin%2C+J">J. Racusin</a>, <a href="/search/astro-ph?searchtype=author&query=Aryan%2C+A">A. Aryan</a>, <a href="/search/astro-ph?searchtype=author&query=Iyyani%2C+S">S. Iyyani</a>, <a href="/search/astro-ph?searchtype=author&query=Vadawale%2C+S">S. Vadawale</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2406.13755v2-abstract-short" style="display: inline;"> The radiation mechanism underlying the prompt emission remains unresolved and can be resolved using a systematic and uniform time-resolved spectro-polarimetric study. In this paper, we investigated the spectral, temporal, and polarimetric characteristics of five bright GRBs using archival data from AstroSat CZTI, Swift BAT, and Fermi GBM. These bright GRBs were detected by CZTI in its first year o… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2406.13755v2-abstract-full').style.display = 'inline'; document.getElementById('2406.13755v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2406.13755v2-abstract-full" style="display: none;"> The radiation mechanism underlying the prompt emission remains unresolved and can be resolved using a systematic and uniform time-resolved spectro-polarimetric study. In this paper, we investigated the spectral, temporal, and polarimetric characteristics of five bright GRBs using archival data from AstroSat CZTI, Swift BAT, and Fermi GBM. These bright GRBs were detected by CZTI in its first year of operation, and their average polarization characteristics have been published in Chattopadhyay et al. (2022). In the present work, we examined the time-resolved (in 100-600 keV) and energy-resolved polarization measurements of these GRBs with an improved polarimetric technique such as increasing the effective area and bandwidth (by using data from low-gain pixels), using an improved event selection logic to reduce noise in the double events and extend the spectral bandwidth. In addition, we also separately carried out detailed time-resolved spectral analyses of these GRBs using empirical and physical synchrotron models. By these improved time-resolved and energy-resolved spectral and polarimetric studies (not fully coupled spectro-polarimetric fitting), we could pin down the elusive prompt emission mechanism of these GRBs. Our spectro-polarimetric analysis reveals that GRB 160623A, GRB 160703A, and GRB 160821A have Poynting flux-dominated jets. On the other hand, GRB 160325A and GRB 160802A have baryonic-dominated jets with mild magnetization. Furthermore, we observe a rapid change in polarization angle by $\sim$ 90 degrees within the main pulse of very bright GRB 160821A, consistent with our previous results. Our study suggests that the jet composition of GRBs may exhibit a wide range of magnetization, which can be revealed by utilizing spectro-polarimetric investigations of the bright GRBs. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2406.13755v2-abstract-full').style.display = 'none'; document.getElementById('2406.13755v2-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, 2024; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 19 June, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> June 2024. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">36 pages, 11 figures, Published in ApJ</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> ApJ 972 166 (2024) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2405.20989">arXiv:2405.20989</a> <span> [<a href="https://arxiv.org/pdf/2405.20989">pdf</a>, <a href="https://arxiv.org/format/2405.20989">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"> Unravelling the asphericities in the explosion and multi-faceted circumstellar matter of SN 2023ixf </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Singh%2C+A">Avinash Singh</a>, <a href="/search/astro-ph?searchtype=author&query=Teja%2C+R+S">R. S. Teja</a>, <a href="/search/astro-ph?searchtype=author&query=Moriya%2C+T+J">T. J. Moriya</a>, <a href="/search/astro-ph?searchtype=author&query=Maeda%2C+K">K. Maeda</a>, <a href="/search/astro-ph?searchtype=author&query=Kawabata%2C+K+S">K. S. Kawabata</a>, <a href="/search/astro-ph?searchtype=author&query=Tanaka%2C+M">M. Tanaka</a>, <a href="/search/astro-ph?searchtype=author&query=Imazawa%2C+R">R. Imazawa</a>, <a href="/search/astro-ph?searchtype=author&query=Nakaoka%2C+T">T. Nakaoka</a>, <a href="/search/astro-ph?searchtype=author&query=Gangopadhyay%2C+A">A. Gangopadhyay</a>, <a href="/search/astro-ph?searchtype=author&query=Yamanaka%2C+M">M. Yamanaka</a>, <a href="/search/astro-ph?searchtype=author&query=Swain%2C+V">V. Swain</a>, <a href="/search/astro-ph?searchtype=author&query=Sahu%2C+D+K">D. K. Sahu</a>, <a href="/search/astro-ph?searchtype=author&query=Anupama%2C+G+C">G. C. Anupama</a>, <a href="/search/astro-ph?searchtype=author&query=Kumar%2C+B">B. Kumar</a>, <a href="/search/astro-ph?searchtype=author&query=Anche%2C+R+M">R. M. Anche</a>, <a href="/search/astro-ph?searchtype=author&query=Sano%2C+Y">Y. Sano</a>, <a href="/search/astro-ph?searchtype=author&query=Raj%2C+A">A. Raj</a>, <a href="/search/astro-ph?searchtype=author&query=Agnihotri%2C+V+K">V. K. Agnihotri</a>, <a href="/search/astro-ph?searchtype=author&query=Bhalerao%2C+V">V. Bhalerao</a>, <a href="/search/astro-ph?searchtype=author&query=Bisht%2C+D">D. Bisht</a>, <a href="/search/astro-ph?searchtype=author&query=Bisht%2C+M+S">M. S. Bisht</a>, <a href="/search/astro-ph?searchtype=author&query=Belwal%2C+K">K. Belwal</a>, <a href="/search/astro-ph?searchtype=author&query=Chakrabarti%2C+S+K">S. K. Chakrabarti</a>, <a href="/search/astro-ph?searchtype=author&query=Fujii%2C+M">M. Fujii</a>, <a href="/search/astro-ph?searchtype=author&query=Nagayama%2C+T">T. Nagayama</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="2405.20989v2-abstract-short" style="display: inline;"> We present a detailed investigation of photometric, spectroscopic, and polarimetric observations of the Type II SN 2023ixf. Earlier studies have provided compelling evidence for a delayed shock breakout from a confined dense circumstellar matter (CSM) enveloping the progenitor star. The temporal evolution of polarization in SN~2023ixf revealed three distinct peaks in polarization evolution at 1.4… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2405.20989v2-abstract-full').style.display = 'inline'; document.getElementById('2405.20989v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2405.20989v2-abstract-full" style="display: none;"> We present a detailed investigation of photometric, spectroscopic, and polarimetric observations of the Type II SN 2023ixf. Earlier studies have provided compelling evidence for a delayed shock breakout from a confined dense circumstellar matter (CSM) enveloping the progenitor star. The temporal evolution of polarization in SN~2023ixf revealed three distinct peaks in polarization evolution at 1.4 d, 6.4 d, and 79.2 d, indicating an asymmetric dense CSM, an aspherical shock front and clumpiness in the low-density extended CSM, and an aspherical inner ejecta/He-core. SN 2023ixf displayed two dominant axes, one along the CSM-outer ejecta and the other along the inner ejecta/He-core, showcasing the independent origin of asymmetry in the early and late evolution. The argument for an aspherical shock front is further strengthened by the presence of a high-velocity broad absorption feature in the blue wing of the Balmer features in addition to the P-Cygni absorption post 16 d. Hydrodynamical light curve modeling indicated a progenitor of 10 solar mass with a radius of 470 solar radii and explosion energy of 2e51 erg, along with 0.06 solar mass of 56-Ni, though these properties are not unique due to modeling degeneracies. The modeling also indicated a two-zone CSM: a confined dense CSM extending up to 5e14 cm, with a mass-loss rate of 1e-2 solar mass per year, and an extended CSM spanning from 5e14 cm to at least 1e16cm with a mass-loss rate of 1e-4 solar mass per year, both assuming a wind-velocity of 10 km/s. The early nebular phase observations display an axisymmetric line profile of [OI], red-ward attenuation of the emission of Halpha post 125 days, and flattening in the Ks-band, marking the onset of dust formation. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2405.20989v2-abstract-full').style.display = 'none'; document.getElementById('2405.20989v2-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 September, 2024; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 31 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">32 pages, 15 figures, 1 Table, Accepted 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/2405.12403">arXiv:2405.12403</a> <span> [<a href="https://arxiv.org/pdf/2405.12403">pdf</a>, <a href="https://arxiv.org/format/2405.12403">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"> Searching for gravitational wave optical counterparts with the Zwicky Transient Facility: summary of O4a </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Ahumada%2C+T">Tom谩s Ahumada</a>, <a href="/search/astro-ph?searchtype=author&query=Anand%2C+S">Shreya Anand</a>, <a href="/search/astro-ph?searchtype=author&query=Coughlin%2C+M+W">Michael W. Coughlin</a>, <a href="/search/astro-ph?searchtype=author&query=Gupta%2C+V">Vaidehi Gupta</a>, <a href="/search/astro-ph?searchtype=author&query=Kasliwal%2C+M+M">Mansi M. Kasliwal</a>, <a href="/search/astro-ph?searchtype=author&query=Karambelkar%2C+V+R">Viraj R. Karambelkar</a>, <a href="/search/astro-ph?searchtype=author&query=Stein%2C+R+D">Robert D. Stein</a>, <a href="/search/astro-ph?searchtype=author&query=Waratkar%2C+G">Gaurav Waratkar</a>, <a href="/search/astro-ph?searchtype=author&query=Swain%2C+V">Vishwajeet Swain</a>, <a href="/search/astro-ph?searchtype=author&query=Laz%2C+T+J+d">Theophile Jegou du Laz</a>, <a href="/search/astro-ph?searchtype=author&query=Anumarlapudi%2C+A">Akash Anumarlapudi</a>, <a href="/search/astro-ph?searchtype=author&query=Andreoni%2C+I">Igor Andreoni</a>, <a href="/search/astro-ph?searchtype=author&query=Bulla%2C+M">Mattia Bulla</a>, <a href="/search/astro-ph?searchtype=author&query=Srinivasaragavan%2C+G+P">Gokul P. Srinivasaragavan</a>, <a href="/search/astro-ph?searchtype=author&query=Toivonen%2C+A">Andrew Toivonen</a>, <a href="/search/astro-ph?searchtype=author&query=Wold%2C+A">Avery Wold</a>, <a href="/search/astro-ph?searchtype=author&query=Bellm%2C+E+C">Eric C. Bellm</a>, <a href="/search/astro-ph?searchtype=author&query=Cenko%2C+S+B">S. Bradley Cenko</a>, <a href="/search/astro-ph?searchtype=author&query=Kaplan%2C+D+L">David L. Kaplan</a>, <a href="/search/astro-ph?searchtype=author&query=Sollerman%2C+J">Jesper Sollerman</a>, <a href="/search/astro-ph?searchtype=author&query=Bhalerao%2C+V">Varun Bhalerao</a>, <a href="/search/astro-ph?searchtype=author&query=Perley%2C+D">Daniel Perley</a>, <a href="/search/astro-ph?searchtype=author&query=Salgundi%2C+A">Anirudh Salgundi</a>, <a href="/search/astro-ph?searchtype=author&query=Suresh%2C+A">Aswin Suresh</a>, <a href="/search/astro-ph?searchtype=author&query=Hinds%2C+K">K-Ryan Hinds</a> , et al. (27 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="2405.12403v1-abstract-short" style="display: inline;"> During the first half of the fourth observing run (O4a) of the International Gravitational Wave Network (IGWN), the Zwicky Transient Facility (ZTF) conducted a systematic search for kilonova (KN) counterparts to binary neutron star (BNS) and neutron star-black hole (NSBH) merger candidates. Here, we present a comprehensive study of the five high-significance (FAR < 1 per year) BNS and NSBH candida… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2405.12403v1-abstract-full').style.display = 'inline'; document.getElementById('2405.12403v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2405.12403v1-abstract-full" style="display: none;"> During the first half of the fourth observing run (O4a) of the International Gravitational Wave Network (IGWN), the Zwicky Transient Facility (ZTF) conducted a systematic search for kilonova (KN) counterparts to binary neutron star (BNS) and neutron star-black hole (NSBH) merger candidates. Here, we present a comprehensive study of the five high-significance (FAR < 1 per year) BNS and NSBH candidates in O4a. Our follow-up campaigns relied on both target-of-opportunity observations (ToO) and re-weighting of the nominal survey schedule to maximize coverage. We describe the toolkit we have been developing, Fritz, an instance of SkyPortal, instrumental in coordinating and managing our telescope scheduling, candidate vetting, and follow-up observations through a user-friendly interface. ZTF covered a total of 2841 deg$^2$ within the skymaps of the high-significance GW events, reaching a median depth of g~20.2 mag. We circulated 15 candidates, but found no viable KN counterpart to any of the GW events. Based on the ZTF non-detections of the high-significance events in O4a, we used a Bayesian approach, nimbus, to quantify the posterior probability of KN model parameters that are consistent with our non-detections. Our analysis favors KNe with initial absolute magnitude fainter than -16 mag. The joint posterior probability of a GW170817-like KN associated with all our O4a follow-ups was 64%. Additionally, we use a survey simulation software, simsurvey, to determine that our combined filtered efficiency to detect a GW170817-like KN is 36%, when considering the 5 confirmed astrophysical events in O3 (1 BNS and 4 NSBH), along with our O4a follow-ups. Following Kasliwal et al. (2020), we derived joint constraints on the underlying KN luminosity function based on our O3 and O4a follow-ups, determining that no more than 76% of KNe fading at 1 mag/day can peak at a magnitude brighter than -17.5 mag. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2405.12403v1-abstract-full').style.display = 'none'; document.getElementById('2405.12403v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 20 May, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> May 2024. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">submitted</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2402.13294">arXiv:2402.13294</a> <span> [<a href="https://arxiv.org/pdf/2402.13294">pdf</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"> Latest Developments and Opportunities in Sky Survey </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Brown%2C+A">Anthony Brown</a>, <a href="/search/astro-ph?searchtype=author&query=Bianco%2C+F">Federica Bianco</a>, <a href="/search/astro-ph?searchtype=author&query=Bhalerao%2C+V">Varun Bhalerao</a>, <a href="/search/astro-ph?searchtype=author&query=Kulkarni%2C+S">Shri Kulkarni</a>, <a href="/search/astro-ph?searchtype=author&query=Cooke%2C+J">Jeffery Cooke</a>, <a href="/search/astro-ph?searchtype=author&query=Reitze%2C+D+H">David H. Reitze</a>, <a href="/search/astro-ph?searchtype=author&query=Sharma%2C+P">Pranav Sharma</a>, <a href="/search/astro-ph?searchtype=author&query=Mahabal%2C+A">Ashish Mahabal</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="2402.13294v1-abstract-short" style="display: inline;"> Policy Brief on "Latest Developments and Opportunities in Sky Survey", distilled from the corresponding panel that was part of the discussions during S20 Policy Webinar on Astroinformatics for Sustainable Development held on 6-7 July 2023. Sky surveys have been a crucial tool in advancing our understanding of the Universe. The last few decades have seen an explosion in the number and scope of sk… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2402.13294v1-abstract-full').style.display = 'inline'; document.getElementById('2402.13294v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2402.13294v1-abstract-full" style="display: none;"> Policy Brief on "Latest Developments and Opportunities in Sky Survey", distilled from the corresponding panel that was part of the discussions during S20 Policy Webinar on Astroinformatics for Sustainable Development held on 6-7 July 2023. Sky surveys have been a crucial tool in advancing our understanding of the Universe. The last few decades have seen an explosion in the number and scope of sky surveys, both ground-based and space-based. This growth has led to a wealth of data that has enabled us to make significant advances in many areas of astronomy, and help understand the physics of the universe. They have helped us discover new astronomical objects, the origin of the elements, dark matter and dark energy, the accelerated expansion of the universe, and gravitational waves. They have helped us study the distribution of neutral and ionized matter in the Universe and test our theories about the origin and evolution of galaxies, stars, and planets. We explore recent advances and potential avenues in sky surveys, and examine how these developments may impact the field of international astronomical research. The policy webinar took place during the G20 presidency in India (2023). A summary based on the seven panels can be found here: arxiv:2401.04623. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2402.13294v1-abstract-full').style.display = 'none'; document.getElementById('2402.13294v1-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 February, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> February 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">5 pages. The panel videos including keynotes and the white papers are available on the S20 site at: https://s20india.org/science-policy-webinar-astroinformatics-for-sustainable-development/</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2402.07564">arXiv:2402.07564</a> <span> [<a href="https://arxiv.org/pdf/2402.07564">pdf</a>, <a href="https://arxiv.org/format/2402.07564">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"> Bright in the Black: Searching for Electromagnetic Counterparts to Gravitational-Wave Candidates in LIGO-Virgo-KAGRA Observation Runs with AstroSat-CZTI </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Waratkar%2C+G">Gaurav Waratkar</a>, <a href="/search/astro-ph?searchtype=author&query=Bhalerao%2C+V">Varun Bhalerao</a>, <a href="/search/astro-ph?searchtype=author&query=Bhattacharya%2C+D">Dipankar Bhattacharya</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="2402.07564v1-abstract-short" style="display: inline;"> GW150914 marked the start of the gravitational wave (GW) era with the direct detection of binary black hole (BBH) merger by the LIGO-Virgo GW detectors. The event was temporally coincident with a weak signal detected by Fermi-GBM, which hinted towards the possibility of electromagnetic emission associated with the compact object coalescence. The detection of a short Gamma-Ray Burst (GRB) associate… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2402.07564v1-abstract-full').style.display = 'inline'; document.getElementById('2402.07564v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2402.07564v1-abstract-full" style="display: none;"> GW150914 marked the start of the gravitational wave (GW) era with the direct detection of binary black hole (BBH) merger by the LIGO-Virgo GW detectors. The event was temporally coincident with a weak signal detected by Fermi-GBM, which hinted towards the possibility of electromagnetic emission associated with the compact object coalescence. The detection of a short Gamma-Ray Burst (GRB) associated with GW1708017, along with several multi-wavelength detections, truly established that compact object mergers are indeed multi-messenger events. The Cadmium Zinc Telluride Imager onboard AstroSat can search for X-ray counterparts of the GW events and has detected over 600 GRBs since launch. Here we present results from our searches for counterparts coincident with GW triggers from the first three LIGO-Virgo-KAGRA (LVK) GW Transient Catalogs. For 72 out of 90 GW events for which AstroSat-CZTI data was available, we undertook a systematic search for temporally coincident transients and we detected no X-ray counterparts. We evaluate the upper limits on the maximum possible flux from the source in a 100 s window centered around each trigger, consistent with the GW localization of the event. Thanks to the high sensitivity of CZTI, these upper limits are highly competitive with those from other spacecraft. We use these upper limits to constrain the theoretical models that predict high-energy counterparts to the BBH mergers. We also discuss the probability of non-detections of BBH mergers at different luminosities and the implications of such non-detections from the ongoing fourth observing run of the LVK detectors. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2402.07564v1-abstract-full').style.display = 'none'; document.getElementById('2402.07564v1-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 February, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> February 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">15 pages, 7 figures, 2 tables. Submitted to The Astrophysical Journal. Comments are 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/2402.02476">arXiv:2402.02476</a> <span> [<a href="https://arxiv.org/pdf/2402.02476">pdf</a>, <a href="https://arxiv.org/format/2402.02476">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> </div> </div> <p class="title is-5 mathjax"> Constraints on Triton atmospheric evolution from occultations: 1989-2022 </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Sicardy%2C+B">B. Sicardy</a>, <a href="/search/astro-ph?searchtype=author&query=Tej%2C+A">A. Tej</a>, <a href="/search/astro-ph?searchtype=author&query=Gomes-Junior%2C+A+R">A. R. Gomes-Junior</a>, <a href="/search/astro-ph?searchtype=author&query=Romanov%2C+F+D">F. D. Romanov</a>, <a href="/search/astro-ph?searchtype=author&query=Bertrand%2C+T">T. Bertrand</a>, <a href="/search/astro-ph?searchtype=author&query=Ashok%2C+N+M">N. M. Ashok</a>, <a href="/search/astro-ph?searchtype=author&query=Lellouch%2C+E">E. Lellouch</a>, <a href="/search/astro-ph?searchtype=author&query=Morgado%2C+B+E">B. E. Morgado</a>, <a href="/search/astro-ph?searchtype=author&query=Assafin%2C+M">M. Assafin</a>, <a href="/search/astro-ph?searchtype=author&query=Desmars%2C+J">J. Desmars</a>, <a href="/search/astro-ph?searchtype=author&query=Camargo%2C+J+I+B">J. I. B. Camargo</a>, <a href="/search/astro-ph?searchtype=author&query=Kilic%2C+Y">Y. Kilic</a>, <a href="/search/astro-ph?searchtype=author&query=Ortiz%2C+J+L">J. L. Ortiz</a>, <a href="/search/astro-ph?searchtype=author&query=Vieira-Martins%2C+R">R. Vieira-Martins</a>, <a href="/search/astro-ph?searchtype=author&query=Braga-Ribas%2C+F">F. Braga-Ribas</a>, <a href="/search/astro-ph?searchtype=author&query=Ninan%2C+J+P">J. P. Ninan</a>, <a href="/search/astro-ph?searchtype=author&query=Bhatt%2C+B+C">B. C. Bhatt</a>, <a href="/search/astro-ph?searchtype=author&query=Kumar%2C+S+P">S. Pramod Kumar</a>, <a href="/search/astro-ph?searchtype=author&query=Swain%2C+V">V. Swain</a>, <a href="/search/astro-ph?searchtype=author&query=Sharma%2C+S">S. Sharma</a>, <a href="/search/astro-ph?searchtype=author&query=Saha%2C+A">A. Saha</a>, <a href="/search/astro-ph?searchtype=author&query=Ojha%2C+D+K">D. K. Ojha</a>, <a href="/search/astro-ph?searchtype=author&query=Pawar%2C+G">G. Pawar</a>, <a href="/search/astro-ph?searchtype=author&query=Deshmukh%2C+S">S. Deshmukh</a>, <a href="/search/astro-ph?searchtype=author&query=Deshpande%2C+A">A. Deshpande</a> , et al. (27 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="2402.02476v1-abstract-short" style="display: inline;"> Context - Around the year 2000, Triton's south pole experienced an extreme summer solstice that occurs every about 650 years, when the subsolar latitude reached about 50掳. Bracketing this epoch, a few occultations probed Triton's atmosphere in 1989, 1995, 1997, 2008 and 2017. A recent ground-based stellar occultation observed on 6 October 2022 provides a new measurement of Triton's atmospheric pre… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2402.02476v1-abstract-full').style.display = 'inline'; document.getElementById('2402.02476v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2402.02476v1-abstract-full" style="display: none;"> Context - Around the year 2000, Triton's south pole experienced an extreme summer solstice that occurs every about 650 years, when the subsolar latitude reached about 50掳. Bracketing this epoch, a few occultations probed Triton's atmosphere in 1989, 1995, 1997, 2008 and 2017. A recent ground-based stellar occultation observed on 6 October 2022 provides a new measurement of Triton's atmospheric pressure which is presented here. Aims- The goal is to constrain the Volatile Transport Models (VTMs) of Triton's atmosphere that is basically in vapor pressure equilibrium with the nitrogen ice at its surface. Methods - Fits to the occultation light curves yield Triton's atmospheric pressure at the reference radius 1400 km, from which the surface pressure is induced. Results - The fits provide a pressure p_1400= 1.211 +/- 0.039 microbar at radius 1400 km (47 km altitude), from which a surface pressure of p_surf= 14.54 +/- 0.47 microbar is induced (1-sigma error bars). To within error bars, this is identical to the pressure derived from the previous occultation of 5 October 2017, p_1400 = 1.18 +/- 0.03 microbar and p_surf= 14.1 +/- 0.4 microbar, respectively. Based on recent models of Triton's volatile cycles, the overall evolution over the last 30 years of the surface pressure is consistent with N2 condensation taking place in the northern hemisphere. However, models typically predict a steady decrease in surface pressure for the period 2005-2060, which is not confirmed by this observation. Complex surface-atmosphere interactions, such as ice albedo runaway and formation of local N2 frosts in the equatorial regions of Triton could explain the relatively constant pressure between 2017 and 2022. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2402.02476v1-abstract-full').style.display = 'none'; document.getElementById('2402.02476v1-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 February, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> February 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">8 pages, 4 figures, accepted for publication in Astronomy and Astrophysics</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2401.16470">arXiv:2401.16470</a> <span> [<a href="https://arxiv.org/pdf/2401.16470">pdf</a>, <a href="https://arxiv.org/ps/2401.16470">ps</a>, <a href="https://arxiv.org/format/2401.16470">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"> AT2019pim: A Luminous Orphan Afterglow from a Moderately Relativistic Outflow </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Perley%2C+D+A">Daniel A. Perley</a>, <a href="/search/astro-ph?searchtype=author&query=Ho%2C+A+Y+Q">Anna Y. Q. Ho</a>, <a href="/search/astro-ph?searchtype=author&query=Fausnaugh%2C+M">Michael Fausnaugh</a>, <a href="/search/astro-ph?searchtype=author&query=Lamb%2C+G+P">Gavin P. Lamb</a>, <a href="/search/astro-ph?searchtype=author&query=Kasliwal%2C+M+M">Mansi M. Kasliwal</a>, <a href="/search/astro-ph?searchtype=author&query=Ahumada%2C+T">Tomas Ahumada</a>, <a href="/search/astro-ph?searchtype=author&query=Anand%2C+S">Shreya Anand</a>, <a href="/search/astro-ph?searchtype=author&query=Andreoni%2C+I">Igor Andreoni</a>, <a href="/search/astro-ph?searchtype=author&query=Bellm%2C+E">Eric Bellm</a>, <a href="/search/astro-ph?searchtype=author&query=Bhalerao%2C+V">Varun Bhalerao</a>, <a href="/search/astro-ph?searchtype=author&query=Bolin%2C+B">Bryce Bolin</a>, <a href="/search/astro-ph?searchtype=author&query=Brink%2C+T+G">Thomas G. Brink</a>, <a href="/search/astro-ph?searchtype=author&query=Burns%2C+E">Eric Burns</a>, <a href="/search/astro-ph?searchtype=author&query=Cenko%2C+S+B">S. Bradley Cenko</a>, <a href="/search/astro-ph?searchtype=author&query=Corsi%2C+A">Alessandra Corsi</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=Frederiks%2C+D">Dmitry Frederiks</a>, <a href="/search/astro-ph?searchtype=author&query=Goldstein%2C+A">Adam Goldstein</a>, <a href="/search/astro-ph?searchtype=author&query=Hamburg%2C+R">Rachel Hamburg</a>, <a href="/search/astro-ph?searchtype=author&query=Jayaraman%2C+R">Rahul Jayaraman</a>, <a href="/search/astro-ph?searchtype=author&query=Jonker%2C+P+G">Peter G. Jonker</a>, <a href="/search/astro-ph?searchtype=author&query=Kool%2C+E+C">Erik C. Kool</a>, <a href="/search/astro-ph?searchtype=author&query=Kulkarni%2C+S">Shrinivas Kulkarni</a>, <a href="/search/astro-ph?searchtype=author&query=Kumar%2C+H">Harsh Kumar</a>, <a href="/search/astro-ph?searchtype=author&query=Laher%2C+R">Russ Laher</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="2401.16470v1-abstract-short" style="display: inline;"> Classical gamma-ray bursts (GRBs) have two distinct emission episodes: prompt emission from ultra-relativistic ejecta and afterglow from shocked circumstellar material. While both components are extremely luminous in known GRBs, a variety of scenarios predict the existence of luminous afterglow emission with little or no associated high-energy prompt emission. We present AT 2019pim, the first secu… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2401.16470v1-abstract-full').style.display = 'inline'; document.getElementById('2401.16470v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2401.16470v1-abstract-full" style="display: none;"> Classical gamma-ray bursts (GRBs) have two distinct emission episodes: prompt emission from ultra-relativistic ejecta and afterglow from shocked circumstellar material. While both components are extremely luminous in known GRBs, a variety of scenarios predict the existence of luminous afterglow emission with little or no associated high-energy prompt emission. We present AT 2019pim, the first secure example of this phenomenon to be identified. Serendipitously discovered during follow-up observations of a gravitational-wave trigger and located in a contemporaneous TESS sector, it is hallmarked by a fast-rising (t ~ 2 hr), luminous (M_UV,peak ~ -24.4 mag) optical transient with accompanying luminous X-ray and radio emission. No gamma-ray emission consistent with the time and location of the transient was detected by Fermi-GBM or by Konus, placing strong limits on an accompanying GRB. We investigate several independent observational aspects of the afterglow in the context of constraints on relativistic motion and find all of them are consistent with an initial Lorentz factor of Gamma_0 ~ 30-50, significantly lower than in any well-observed GRB and consistent with the theoretically-predicted "dirty fireball" scenario in which the high-energy prompt emission is stifled by pair production. However, we cannot rule out a structured jet model in which only the line-of-sight material was ejected at low-Gamma, off-axis from a classical high-Gamma jet core. This event represents a milestone in orphan afterglow searches, demonstrating that luminous afterglows with weak or no detectable gamma-ray radiation exist in nature and can be discovered by high-cadence optical surveys. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2401.16470v1-abstract-full').style.display = 'none'; document.getElementById('2401.16470v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 29 January, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> January 2024. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">Submitted to MNRAS</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2401.16404">arXiv:2401.16404</a> <span> [<a href="https://arxiv.org/pdf/2401.16404">pdf</a>, <a href="https://arxiv.org/format/2401.16404">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"> Localisation of Gamma Ray Bursts using AstroSat Mass Model </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Saraogi%2C+D">Divita Saraogi</a>, <a href="/search/astro-ph?searchtype=author&query=Aditya%2C+J+V">J Venkata Aditya</a>, <a href="/search/astro-ph?searchtype=author&query=Bhalerao%2C+V">Varun Bhalerao</a>, <a href="/search/astro-ph?searchtype=author&query=Bala%2C+S">Suman Bala</a>, <a href="/search/astro-ph?searchtype=author&query=Balasubramanian%2C+A">Arvind Balasubramanian</a>, <a href="/search/astro-ph?searchtype=author&query=Mate%2C+S">Sujay Mate</a>, <a href="/search/astro-ph?searchtype=author&query=Chattopadhyay%2C+T">Tanmoy Chattopadhyay</a>, <a href="/search/astro-ph?searchtype=author&query=Gupta%2C+S">Soumya Gupta</a>, <a href="/search/astro-ph?searchtype=author&query=Prasad%2C+V">Vipul Prasad</a>, <a href="/search/astro-ph?searchtype=author&query=Waratkar%2C+G">Gaurav Waratkar</a>, <a href="/search/astro-ph?searchtype=author&query=K%2C+N+P">Navaneeth P K</a>, <a href="/search/astro-ph?searchtype=author&query=Gopalakrishnan%2C+R">Rahul Gopalakrishnan</a>, <a href="/search/astro-ph?searchtype=author&query=Bhattacharya%2C+D">Dipankar Bhattacharya</a>, <a href="/search/astro-ph?searchtype=author&query=Dewangan%2C+G">Gulab Dewangan</a>, <a href="/search/astro-ph?searchtype=author&query=Vadawale%2C+S">Santosh Vadawale</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="2401.16404v1-abstract-short" style="display: inline;"> The Cadmium Zinc Telluride Imager (CZTI) aboard AstroSat has good sensitivity to Gamma Ray Bursts (GRBs), with close to 600 detections including about 50 discoveries undetected by other missions. However, CZTI was not designed to be a GRB monitor and lacks localisation capabilities. We introduce a new method of localising GRBs using "shadows" cast on the CZTI detector plane due to absorption and s… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2401.16404v1-abstract-full').style.display = 'inline'; document.getElementById('2401.16404v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2401.16404v1-abstract-full" style="display: none;"> The Cadmium Zinc Telluride Imager (CZTI) aboard AstroSat has good sensitivity to Gamma Ray Bursts (GRBs), with close to 600 detections including about 50 discoveries undetected by other missions. However, CZTI was not designed to be a GRB monitor and lacks localisation capabilities. We introduce a new method of localising GRBs using "shadows" cast on the CZTI detector plane due to absorption and scattering by satellite components and instruments. Comparing the observed distribution of counts on the detector plane with simulated distributions with the AstroSat Mass Model, we can localise GRBs in the sky. Our localisation uncertainty is defined by a two-component model, with a narrow Gaussian component that has close to 50% probability of containing the source, and the remaining spread over a broader Gaussian component with an 11.3 times higher $蟽$. The width ($蟽$) of the Gaussian components scales inversely with source counts. We test this model by applying the method to GRBs with known positions and find good agreement between the model and observations. This new ability expands the utility of CZTI in the study of GRBs and other rapid high-energy transients. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2401.16404v1-abstract-full').style.display = 'none'; document.getElementById('2401.16404v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 29 January, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> January 2024. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">9 pages, 5 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/2401.13636">arXiv:2401.13636</a> <span> [<a href="https://arxiv.org/pdf/2401.13636">pdf</a>, <a href="https://arxiv.org/format/2401.13636">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"> Joint gravitational wave-short GRB detection of Binary Neutron Star mergers with existing and future facilities </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Bhattacharjee%2C+S">Soumyadeep Bhattacharjee</a>, <a href="/search/astro-ph?searchtype=author&query=Banerjee%2C+S">Smaranika Banerjee</a>, <a href="/search/astro-ph?searchtype=author&query=Bhalerao%2C+V">Varun Bhalerao</a>, <a href="/search/astro-ph?searchtype=author&query=Beniamini%2C+P">Paz Beniamini</a>, <a href="/search/astro-ph?searchtype=author&query=Bose%2C+S">Sukanta Bose</a>, <a href="/search/astro-ph?searchtype=author&query=Hotokezaka%2C+K">Kenta Hotokezaka</a>, <a href="/search/astro-ph?searchtype=author&query=Pai%2C+A">Archana Pai</a>, <a href="/search/astro-ph?searchtype=author&query=Saleem%2C+M">Muhammed Saleem</a>, <a href="/search/astro-ph?searchtype=author&query=Waratkar%2C+G">Gaurav Waratkar</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="2401.13636v1-abstract-short" style="display: inline;"> We explore the joint detection prospects of short gamma-ray bursts (sGRBs) and their gravitational wave (GW) counterparts by the current and upcoming high-energy GRB and GW facilities from binary neutron star (BNS) mergers. We consider two GW detector networks: (1) A four-detector network comprising LIGO Hanford, Livingston, Virgo, and Kagra, (IGWN4) and (2) a future five-detector network includin… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2401.13636v1-abstract-full').style.display = 'inline'; document.getElementById('2401.13636v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2401.13636v1-abstract-full" style="display: none;"> We explore the joint detection prospects of short gamma-ray bursts (sGRBs) and their gravitational wave (GW) counterparts by the current and upcoming high-energy GRB and GW facilities from binary neutron star (BNS) mergers. We consider two GW detector networks: (1) A four-detector network comprising LIGO Hanford, Livingston, Virgo, and Kagra, (IGWN4) and (2) a future five-detector network including the same four detectors and LIGO India (IGWN5). For the sGRB detection, we consider existing satellites Fermi and Swift and the proposed all-sky satellite Daksha. Most of the events for the joint detection will be off-axis, hence, we consider a broad range of sGRB jet models predicting the off-axis emission. Also, to test the effect of the assumed sGRB luminosity function, we consider two different functions for one of the emission models. We find that for the different jet models, the joint sGRB and GW detection rates for Fermi and Swift with IGWN4 (IGWN5) lie within 0.07-0.62$\mathrm{\ yr^{-1}}$ (0.8-4.0$\mathrm{\ yr^{-1}}$) and 0.02-0.14$\mathrm{\ yr^{-1}}$ (0.15-1.0$\mathrm{\ yr^{-1}}$), respectively, when the BNS merger rate is taken to be 320$\mathrm{\ Gpc^{-3}~yr^{-1}}$. With Daksha, the rates increase to 0.2-1.3$\mathrm{\ yr^{-1}}$ (1.3-8.3$\mathrm{\ yr^{-1}}$), which is 2-9 times higher than the existing satellites. We show that such a mission with higher sensitivity will be ideal for detecting a higher number of fainter events observed off-axis or at a larger distance. Thus, Daksha will boost the joint detections of sGRB and GW, especially for the off-axis events. Finally, we find that our detection rates with optimal SNRs are conservative, and noise in GW detectors can increase the rates further. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2401.13636v1-abstract-full').style.display = 'none'; document.getElementById('2401.13636v1-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 January, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> January 2024. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">9 pages, 6 figures, 2 tables; accepted for publication in MNRAS. The definitive version will be available on the journal page</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2401.04623">arXiv:2401.04623</a> <span> [<a href="https://arxiv.org/pdf/2401.04623">pdf</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="Data Analysis, Statistics and Probability">physics.data-an</span> </div> </div> <p class="title is-5 mathjax"> AstroInformatics: Recommendations for Global Cooperation </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Mahabal%2C+A">Ashish Mahabal</a>, <a href="/search/astro-ph?searchtype=author&query=Sharma%2C+P">Pranav Sharma</a>, <a href="/search/astro-ph?searchtype=author&query=Adhikari%2C+R">Rana Adhikari</a>, <a href="/search/astro-ph?searchtype=author&query=Allen%2C+M">Mark Allen</a>, <a href="/search/astro-ph?searchtype=author&query=Andreon%2C+S">Stefano Andreon</a>, <a href="/search/astro-ph?searchtype=author&query=Bhalerao%2C+V">Varun Bhalerao</a>, <a href="/search/astro-ph?searchtype=author&query=Bianco%2C+F">Federica Bianco</a>, <a href="/search/astro-ph?searchtype=author&query=Brown%2C+A">Anthony Brown</a>, <a href="/search/astro-ph?searchtype=author&query=Cenko%2C+S+B">S. Bradley Cenko</a>, <a href="/search/astro-ph?searchtype=author&query=Coehlo%2C+P">Paula Coehlo</a>, <a href="/search/astro-ph?searchtype=author&query=Cooke%2C+J">Jeffery Cooke</a>, <a href="/search/astro-ph?searchtype=author&query=Crichton%2C+D">Daniel Crichton</a>, <a href="/search/astro-ph?searchtype=author&query=Cui%2C+C">Chenzhou Cui</a>, <a href="/search/astro-ph?searchtype=author&query=de+Carvalho%2C+R">Reinaldo de Carvalho</a>, <a href="/search/astro-ph?searchtype=author&query=Doyle%2C+R">Richard Doyle</a>, <a href="/search/astro-ph?searchtype=author&query=Eyer%2C+L">Laurent Eyer</a>, <a href="/search/astro-ph?searchtype=author&query=Fanaroff%2C+B">Bernard Fanaroff</a>, <a href="/search/astro-ph?searchtype=author&query=Fluke%2C+C">Christopher Fluke</a>, <a href="/search/astro-ph?searchtype=author&query=Forster%2C+F">Francisco Forster</a>, <a href="/search/astro-ph?searchtype=author&query=Govender%2C+K">Kevin Govender</a>, <a href="/search/astro-ph?searchtype=author&query=Graham%2C+M+J">Matthew J. Graham</a>, <a href="/search/astro-ph?searchtype=author&query=Hlo%C5%BEek%2C+R">Ren茅e Hlo啪ek</a>, <a href="/search/astro-ph?searchtype=author&query=Irawati%2C+P">Puji Irawati</a>, <a href="/search/astro-ph?searchtype=author&query=Kembhavi%2C+A">Ajit Kembhavi</a>, <a href="/search/astro-ph?searchtype=author&query=Kollmeier%2C+J">Juna Kollmeier</a> , et al. (23 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="2401.04623v1-abstract-short" style="display: inline;"> Policy Brief on "AstroInformatics, Recommendations for Global Collaboration", distilled from panel discussions during S20 Policy Webinar on Astroinformatics for Sustainable Development held on 6-7 July 2023. The deliberations encompassed a wide array of topics, including broad astroinformatics, sky surveys, large-scale international initiatives, global data repositories, space-related data, regi… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2401.04623v1-abstract-full').style.display = 'inline'; document.getElementById('2401.04623v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2401.04623v1-abstract-full" style="display: none;"> Policy Brief on "AstroInformatics, Recommendations for Global Collaboration", distilled from panel discussions during S20 Policy Webinar on Astroinformatics for Sustainable Development held on 6-7 July 2023. The deliberations encompassed a wide array of topics, including broad astroinformatics, sky surveys, large-scale international initiatives, global data repositories, space-related data, regional and international collaborative efforts, as well as workforce development within the field. These discussions comprehensively addressed the current status, notable achievements, and the manifold challenges that the field of astroinformatics currently confronts. The G20 nations present a unique opportunity due to their abundant human and technological capabilities, coupled with their widespread geographical representation. Leveraging these strengths, significant strides can be made in various domains. These include, but are not limited to, the advancement of STEM education and workforce development, the promotion of equitable resource utilization, and contributions to fields such as Earth Science and Climate Science. We present a concise overview, followed by specific recommendations that pertain to both ground-based and space data initiatives. Our team remains readily available to furnish further elaboration on any of these proposals as required. Furthermore, we anticipate further engagement during the upcoming G20 presidencies in Brazil (2024) and South Africa (2025) to ensure the continued discussion and realization of these objectives. The policy webinar took place during the G20 presidency in India (2023). Notes based on the seven panels will be separately published. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2401.04623v1-abstract-full').style.display = 'none'; document.getElementById('2401.04623v1-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 January, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> January 2024. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">7 pages</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2311.10195">arXiv:2311.10195</a> <span> [<a href="https://arxiv.org/pdf/2311.10195">pdf</a>, <a href="https://arxiv.org/format/2311.10195">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/10.1038/s41586-023-06673-6">10.1038/s41586-023-06673-6 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Minutes-duration Optical Flares with Supernova Luminosities </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Ho%2C+A+Y+Q">Anna Y. Q. Ho</a>, <a href="/search/astro-ph?searchtype=author&query=Perley%2C+D+A">Daniel A. Perley</a>, <a href="/search/astro-ph?searchtype=author&query=Chen%2C+P">Ping Chen</a>, <a href="/search/astro-ph?searchtype=author&query=Schulze%2C+S">Steve Schulze</a>, <a href="/search/astro-ph?searchtype=author&query=Dhillon%2C+V">Vik Dhillon</a>, <a href="/search/astro-ph?searchtype=author&query=Kumar%2C+H">Harsh Kumar</a>, <a href="/search/astro-ph?searchtype=author&query=Suresh%2C+A">Aswin Suresh</a>, <a href="/search/astro-ph?searchtype=author&query=Swain%2C+V">Vishwajeet Swain</a>, <a href="/search/astro-ph?searchtype=author&query=Bremer%2C+M">Michael Bremer</a>, <a href="/search/astro-ph?searchtype=author&query=Smartt%2C+S+J">Stephen J. Smartt</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=Anupama%2C+G+C">G. C. Anupama</a>, <a href="/search/astro-ph?searchtype=author&query=Awiphan%2C+S">Supachai Awiphan</a>, <a href="/search/astro-ph?searchtype=author&query=Barway%2C+S">Sudhanshu Barway</a>, <a href="/search/astro-ph?searchtype=author&query=Bellm%2C+E+C">Eric C. Bellm</a>, <a href="/search/astro-ph?searchtype=author&query=Ben-Ami%2C+S">Sagi Ben-Ami</a>, <a href="/search/astro-ph?searchtype=author&query=Bhalerao%2C+V">Varun Bhalerao</a>, <a href="/search/astro-ph?searchtype=author&query=de+Boer%2C+T">Thomas de Boer</a>, <a href="/search/astro-ph?searchtype=author&query=Brink%2C+T+G">Thomas G. Brink</a>, <a href="/search/astro-ph?searchtype=author&query=Burruss%2C+R">Rick Burruss</a>, <a href="/search/astro-ph?searchtype=author&query=Chandra%2C+P">Poonam Chandra</a>, <a href="/search/astro-ph?searchtype=author&query=Chen%2C+T">Ting-Wan Chen</a>, <a href="/search/astro-ph?searchtype=author&query=Chen%2C+W">Wen-Ping Chen</a>, <a href="/search/astro-ph?searchtype=author&query=Cooke%2C+J">Jeff Cooke</a>, <a href="/search/astro-ph?searchtype=author&query=Coughlin%2C+M+W">Michael W. Coughlin</a> , et al. (52 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="2311.10195v1-abstract-short" style="display: inline;"> In recent years, certain luminous extragalactic optical transients have been observed to last only a few days. Their short observed duration implies a different powering mechanism from the most common luminous extragalactic transients (supernovae) whose timescale is weeks. Some short-duration transients, most notably AT2018cow, display blue optical colours and bright radio and X-ray emission. Seve… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2311.10195v1-abstract-full').style.display = 'inline'; document.getElementById('2311.10195v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2311.10195v1-abstract-full" style="display: none;"> In recent years, certain luminous extragalactic optical transients have been observed to last only a few days. Their short observed duration implies a different powering mechanism from the most common luminous extragalactic transients (supernovae) whose timescale is weeks. Some short-duration transients, most notably AT2018cow, display blue optical colours and bright radio and X-ray emission. Several AT2018cow-like transients have shown hints of a long-lived embedded energy source, such as X-ray variability, prolonged ultraviolet emission, a tentative X-ray quasiperiodic oscillation, and large energies coupled to fast (but subrelativistic) radio-emitting ejecta. Here we report observations of minutes-duration optical flares in the aftermath of an AT2018cow-like transient, AT2022tsd (the "Tasmanian Devil"). The flares occur over a period of months, are highly energetic, and are likely nonthermal, implying that they arise from a near-relativistic outflow or jet. Our observations confirm that in some AT2018cow-like transients the embedded energy source is a compact object, either a magnetar or an accreting black hole. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2311.10195v1-abstract-full').style.display = 'none'; document.getElementById('2311.10195v1-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 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">79 pages, 3 figures (main text) + 7 figures (extended data) + 2 figures (supplementary information). Published online in Nature on 15 November 2023</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2311.06620">arXiv:2311.06620</a> <span> [<a href="https://arxiv.org/pdf/2311.06620">pdf</a>, <a href="https://arxiv.org/format/2311.06620">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="High Energy Astrophysical Phenomena">astro-ph.HE</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Instrumentation and Methods for Astrophysics">astro-ph.IM</span> </div> </div> <p class="title is-5 mathjax"> Quantifying Period Uncertainty in X-ray Pulsars with Poisson-Limited Data </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Singhal%2C+A">Akshat Singhal</a>, <a href="/search/astro-ph?searchtype=author&query=Jain%2C+I">Ishan Jain</a>, <a href="/search/astro-ph?searchtype=author&query=Bala%2C+S">Suman Bala</a>, <a href="/search/astro-ph?searchtype=author&query=Bhalerao%2C+V">Varun Bhalerao</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="2311.06620v1-abstract-short" style="display: inline;"> There have been significant developments in the period estimation tools and methods for analysing high energy pulsars in the past few decades. However, these tools lack well-standardised methods for calculating uncertainties in period estimation and other recovered parameters for Poisson--dominated data. Error estimation is important for assigning confidence intervals to the models we study, but d… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2311.06620v1-abstract-full').style.display = 'inline'; document.getElementById('2311.06620v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2311.06620v1-abstract-full" style="display: none;"> There have been significant developments in the period estimation tools and methods for analysing high energy pulsars in the past few decades. However, these tools lack well-standardised methods for calculating uncertainties in period estimation and other recovered parameters for Poisson--dominated data. Error estimation is important for assigning confidence intervals to the models we study, but due to their high computational cost, errors in the pulsar periods were largely ignored in the past. Furthermore, existing literature has often employed semi-analytical techniques that lack rigorous mathematical foundations or exhibit a predominant emphasis on the analysis of white noise and time series data. We present results from our numerical and analytical study of the error distribution of the recovered parameters of high energy pulsar data using the $Z_n^2$ method. We comprehensively formalise the measure of error for the generic pulsar period with much higher reliability than some common methods. Our error estimation method becomes more reliable and robust when observing pulsars for few kilo-seconds, especially for typical pulsars with periods ranging from a few milliseconds to a few seconds. We have verified our results with observations of the \emph{Crab} pulsar, as well as a large set of simulated pulsars. Our codes are publicly available for use. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2311.06620v1-abstract-full').style.display = 'none'; document.getElementById('2311.06620v1-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 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">18 pages, 23 figures, pre-print</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2310.14397">arXiv:2310.14397</a> <span> [<a href="https://arxiv.org/pdf/2310.14397">pdf</a>, <a href="https://arxiv.org/format/2310.14397">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"> Characterizing the Ordinary Broad-lined Type Ic SN 2023pel from the Energetic GRB 230812B </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Srinivasaragavan%2C+G+P">Gokul P. Srinivasaragavan</a>, <a href="/search/astro-ph?searchtype=author&query=Swain%2C+V">Vishwajeet Swain</a>, <a href="/search/astro-ph?searchtype=author&query=O%27Connor%2C+B+M">Brendan M. O'Connor</a>, <a href="/search/astro-ph?searchtype=author&query=Anand%2C+S">Shreya Anand</a>, <a href="/search/astro-ph?searchtype=author&query=Ahumada%2C+T">Tom谩s Ahumada</a>, <a href="/search/astro-ph?searchtype=author&query=Perley%2C+D+A">Daniel A. Perley</a>, <a href="/search/astro-ph?searchtype=author&query=Stein%2C+R">Robert Stein</a>, <a href="/search/astro-ph?searchtype=author&query=Sollerman%2C+J">Jesper Sollerman</a>, <a href="/search/astro-ph?searchtype=author&query=Fremling%2C+C">Christoffer Fremling</a>, <a href="/search/astro-ph?searchtype=author&query=Cenko%2C+S+B">S. Bradley Cenko</a>, <a href="/search/astro-ph?searchtype=author&query=Antier%2C+S">Sarah Antier</a>, <a href="/search/astro-ph?searchtype=author&query=Guessoum%2C+N">Nidhal Guessoum</a>, <a href="/search/astro-ph?searchtype=author&query=Hussenot-Desenonges%2C+T">Thomas Hussenot-Desenonges</a>, <a href="/search/astro-ph?searchtype=author&query=Hello%2C+P">Patrice Hello</a>, <a href="/search/astro-ph?searchtype=author&query=Lesage%2C+S">Stephen Lesage</a>, <a href="/search/astro-ph?searchtype=author&query=Hammerstein%2C+E">Erica Hammerstein</a>, <a href="/search/astro-ph?searchtype=author&query=Miller%2C+M+C">M. Coleman Miller</a>, <a href="/search/astro-ph?searchtype=author&query=Andreoni%2C+I">Igor Andreoni</a>, <a href="/search/astro-ph?searchtype=author&query=Bhalerao%2C+V">Varun Bhalerao</a>, <a href="/search/astro-ph?searchtype=author&query=Bloom%2C+J+S">Joshua S. Bloom</a>, <a href="/search/astro-ph?searchtype=author&query=Dutta%2C+A">Anirban Dutta</a>, <a href="/search/astro-ph?searchtype=author&query=Gal-Yam%2C+A">Avishay Gal-Yam</a>, <a href="/search/astro-ph?searchtype=author&query=Hinds%2C+K">K-Ryan Hinds</a>, <a href="/search/astro-ph?searchtype=author&query=Jaodand%2C+A+D">Amruta D. Jaodand</a>, <a href="/search/astro-ph?searchtype=author&query=Kasliwal%2C+M+M">Mansi M. Kasliwal</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="2310.14397v2-abstract-short" style="display: inline;"> We report observations of the optical counterpart of the long gamma-ray burst (LGRB) GRB 230812B, and its associated supernova (SN) SN 2023pel. The proximity ($z = 0.36$) and high energy ($E_{纬, \rm{iso}} \sim 10^{53}$ erg) make it an important event to study as a probe of the connection between massive star core-collapse and relativistic jet formation. With a phenomenological power-law model for… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2310.14397v2-abstract-full').style.display = 'inline'; document.getElementById('2310.14397v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2310.14397v2-abstract-full" style="display: none;"> We report observations of the optical counterpart of the long gamma-ray burst (LGRB) GRB 230812B, and its associated supernova (SN) SN 2023pel. The proximity ($z = 0.36$) and high energy ($E_{纬, \rm{iso}} \sim 10^{53}$ erg) make it an important event to study as a probe of the connection between massive star core-collapse and relativistic jet formation. With a phenomenological power-law model for the optical afterglow, we find a late-time flattening consistent with the presence of an associated SN. SN 2023pel has an absolute peak $r$-band magnitude of $M_r = -19.46 \pm 0.18$ mag (about as bright as SN 1998bw) and evolves on quicker timescales. Using a radioactive heating model, we derive a nickel mass powering the SN of $M_{\rm{Ni}} = 0.38 \pm 0.01$ $\rm{M_\odot}$, and a peak bolometric luminosity of $L_{\rm{bol}} \sim 1.3 \times 10^{43}$ $\rm{erg}$ $\rm{s^{-1}}$. We confirm SN 2023pel's classification as a broad-lined Type Ic SN with a spectrum taken 15.5 days after its peak in $r$ band, and derive a photospheric expansion velocity of $v_{\rm{ph}} = 11,300 \pm 1,600$ $\rm{km}$ $\rm{s^{-1}}$ at that phase. Extrapolating this velocity to the time of maximum light, we derive the ejecta mass $M_{\rm{ej}} = 1.0 \pm 0.6$ $\rm{M_\odot}$ and kinetic energy $E_{\rm{KE}} = 1.3^{+3.3}_{-1.2} \times10^{51}$ $\rm{erg}$. We find that GRB 230812B/SN 2023pel has SN properties that are mostly consistent with the overall GRB-SN population. The lack of correlations found in the GRB-SN population between SN brightness and $E_{纬, \rm{iso}}$ for their associated GRBs, across a broad range of 7 orders of magnitude, provides further evidence that the central engine powering the relativistic ejecta is not coupled to the SN powering mechanism in GRB-SN systems. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2310.14397v2-abstract-full').style.display = 'none'; document.getElementById('2310.14397v2-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 December, 2023; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 22 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">21 pages, 7 Figures, 1 Table, Accepted to ApJ Letters</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2308.01775">arXiv:2308.01775</a> <span> [<a href="https://arxiv.org/pdf/2308.01775">pdf</a>, <a href="https://arxiv.org/format/2308.01775">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="High Energy Astrophysical Phenomena">astro-ph.HE</span> </div> </div> <p class="title is-5 mathjax"> On the feasibility of primordial black hole abundance constraints using lensing parallax of GRBs </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Gawade%2C+P">Priyanka Gawade</a>, <a href="/search/astro-ph?searchtype=author&query=More%2C+S">Surhud More</a>, <a href="/search/astro-ph?searchtype=author&query=Bhalerao%2C+V">Varun Bhalerao</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="2308.01775v2-abstract-short" style="display: inline;"> Primordial black holes, which could have formed during the early Universe through overdensities in primordial density fluctuations during inflation, are potential candidates for dark matter. We explore the use of lensing parallax of Gamma ray bursts (GRBs), which results in different fluxes being observed from two different vantage points, in order to probe the abundance of primordial black holes… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2308.01775v2-abstract-full').style.display = 'inline'; document.getElementById('2308.01775v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2308.01775v2-abstract-full" style="display: none;"> Primordial black holes, which could have formed during the early Universe through overdensities in primordial density fluctuations during inflation, are potential candidates for dark matter. We explore the use of lensing parallax of Gamma ray bursts (GRBs), which results in different fluxes being observed from two different vantage points, in order to probe the abundance of primordial black holes in the unexplored window within the mass range $[10^{-15}-10^{-11}]M_\odot$. We derive the optical depth for the lensing of GRBs with a distribution of source properties and realistic detector sensitivities. We comment on the ability of the proposed Indian twin satellite mission Daksha in its low earth orbit to conduct this experiment. If the two Daksha satellites observe 10000 GRBs simultaneously and the entirety of dark matter is made up of $[10^{-15}-10^{-12}]M_\odot$ black holes, Daksha will detect non-zero lensing events with a probability ranging from 80 to 50 per cent at the bin edges, respectively. Non-detections will not conclusively rule out primordial black holes as dark matter in this mass range. However, we show that meaningful constraints can be obtained in such a case if the two satellites are separated by at least the Earth-Moon distance. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2308.01775v2-abstract-full').style.display = 'none'; document.getElementById('2308.01775v2-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 30 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">10 pages, 7 figures, updated according to referee's comments, accepted for publication in MNRAS</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2306.16781">arXiv:2306.16781</a> <span> [<a href="https://arxiv.org/pdf/2306.16781">pdf</a>, <a href="https://arxiv.org/format/2306.16781">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/10.1117/1.JATIS.9.4.048002">10.1117/1.JATIS.9.4.048002 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Prospects of measuring Gamma-ray Burst Polarisation with the Daksha mission </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Bala%2C+S">Suman Bala</a>, <a href="/search/astro-ph?searchtype=author&query=Mate%2C+S">Sujay Mate</a>, <a href="/search/astro-ph?searchtype=author&query=Mehla%2C+A">Advait Mehla</a>, <a href="/search/astro-ph?searchtype=author&query=Sastry%2C+P">Parth Sastry</a>, <a href="/search/astro-ph?searchtype=author&query=Mithun%2C+N+P+S">N. P. S. Mithun</a>, <a href="/search/astro-ph?searchtype=author&query=Palit%2C+S">Sourav Palit</a>, <a href="/search/astro-ph?searchtype=author&query=Chanda%2C+M+V">Mehul Vijay Chanda</a>, <a href="/search/astro-ph?searchtype=author&query=Saraogi%2C+D">Divita Saraogi</a>, <a href="/search/astro-ph?searchtype=author&query=Vaishnava%2C+C+S">C. S. Vaishnava</a>, <a href="/search/astro-ph?searchtype=author&query=Waratkar%2C+G">Gaurav Waratkar</a>, <a href="/search/astro-ph?searchtype=author&query=Bhalerao%2C+V">Varun Bhalerao</a>, <a href="/search/astro-ph?searchtype=author&query=Bhattacharya%2C+D">Dipankar Bhattacharya</a>, <a href="/search/astro-ph?searchtype=author&query=Tendulkar%2C+S">Shriharsh Tendulkar</a>, <a href="/search/astro-ph?searchtype=author&query=Vadawale%2C+S">Santosh Vadawale</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2306.16781v2-abstract-short" style="display: inline;"> The proposed Daksha mission comprises of a pair of highly sensitive space telescopes for detecting and characterising high-energy transients such as electromagnetic counterparts of gravitational wave events and gamma-ray bursts (GRBs). Along with spectral and timing analysis, Daksha can also undertake polarisation studies of these transients, providing data crucial for understanding the source geo… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2306.16781v2-abstract-full').style.display = 'inline'; document.getElementById('2306.16781v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2306.16781v2-abstract-full" style="display: none;"> The proposed Daksha mission comprises of a pair of highly sensitive space telescopes for detecting and characterising high-energy transients such as electromagnetic counterparts of gravitational wave events and gamma-ray bursts (GRBs). Along with spectral and timing analysis, Daksha can also undertake polarisation studies of these transients, providing data crucial for understanding the source geometry and physical processes governing high-energy emission. Each Daksha satellite will have 340 pixelated Cadmium Zinc Telluride (CZT) detectors arranged in a quasi-hemispherical configuration without any field-of-view collimation (open detectors). These CZT detectors are good polarimeters in the energy range 100 -- 400 keV, and their ability to measure polarisation has been successfully demonstrated by the Cadmium Zinc Telluride Imager (CZTI) onboard AstroSat. Here we demonstrate the hard X-ray polarisation measurement capabilities of Daksha and estimate the polarisation measurement sensitivity (in terms of the Minimum Detectable Polarisation: MDP) using extensive simulations. We find that Daksha will have MDP of~$30\%$ for a fluence threshold of $10^{-4}$ erg cm$^2$ (in 10 -- 1000 keV). We estimate that with this sensitivity, if GRBs are highly polarised, Daksha can measure the polarisation of about five GRBs per year. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2306.16781v2-abstract-full').style.display = 'none'; document.getElementById('2306.16781v2-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 1 November, 2023; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 29 June, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> June 2023. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">Published in Journal of Astronomical Telescopes, Instruments, and Systems (JATIS)</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Journal of Astronomical Telescopes, Instruments, and Systems, Vol. 9, Issue 4, 048002 (October 2023) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2306.16519">arXiv:2306.16519</a> <span> [<a href="https://arxiv.org/pdf/2306.16519">pdf</a>, <a href="https://arxiv.org/format/2306.16519">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="Earth and Planetary Astrophysics">astro-ph.EP</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/stad1989">10.1093/mnras/stad1989 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Astreaks: Astrometry of NEOs with trailed background stars </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Sharma%2C+K">Kritti Sharma</a>, <a href="/search/astro-ph?searchtype=author&query=Kumar%2C+H">Harsh Kumar</a>, <a href="/search/astro-ph?searchtype=author&query=Choudhary%2C+H">Harsh Choudhary</a>, <a href="/search/astro-ph?searchtype=author&query=Bhalerao%2C+V">Varun Bhalerao</a>, <a href="/search/astro-ph?searchtype=author&query=Swain%2C+V">Vishwajeet Swain</a>, <a href="/search/astro-ph?searchtype=author&query=Bolin%2C+B">Bryce Bolin</a>, <a href="/search/astro-ph?searchtype=author&query=Anupama%2C+G+C">G. C. Anupama</a>, <a href="/search/astro-ph?searchtype=author&query=Barway%2C+S">Sudhanshu Barway</a>, <a href="/search/astro-ph?searchtype=author&query=Joharle%2C+S">Simran Joharle</a>, <a href="/search/astro-ph?searchtype=author&query=Shenoy%2C+V">Vedant Shenoy</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2306.16519v1-abstract-short" style="display: inline;"> The detection and accurate astrometry of fast-moving near-Earth objects (NEOs) has been a challenge for the follow-up community. Their fast apparent motion results in streaks in sidereal images, thus affecting the telescope's limiting magnitude and astrometric accuracy. A widely adopted technique to mitigate trailing losses is non-sidereal tracking, which transfers the streaking to background refe… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2306.16519v1-abstract-full').style.display = 'inline'; document.getElementById('2306.16519v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2306.16519v1-abstract-full" style="display: none;"> The detection and accurate astrometry of fast-moving near-Earth objects (NEOs) has been a challenge for the follow-up community. Their fast apparent motion results in streaks in sidereal images, thus affecting the telescope's limiting magnitude and astrometric accuracy. A widely adopted technique to mitigate trailing losses is non-sidereal tracking, which transfers the streaking to background reference stars. However, no existing publicly available astrometry software is configured to detect such elongated stars. We present Astreaks, a streaking source detection algorithm, to obtain accurate astrometry of NEOs in non-sidereal data. We validate the astrometric accuracy of Astreaks on 371 non-sidereally tracked images for 115 NEOs with two instrument set-ups of the GROWTH-India Telescope. The observed NEOs had V-band magnitude in the range [15, 22] with proper motion up to 140$^{\prime\prime}$/min, thus resulting in stellar streaks as high as 6.5$^\prime$ (582 pixels) in our data. Our method obtained astrometric solutions for all images with 100% success rate. The standard deviation in Observed-minus-Computed (O-C) residuals is 0.52$^{\prime\prime}$, with O-C residuals <2$^{\prime\prime}$(<1$^{\prime\prime}$) for 98.4% (84.4%) of our measurements. These are appreciable, given the pixel scale of $\sim$0.3$^{\prime\prime}$ and $\sim$0.7$^{\prime\prime}$ of our two instrument set-ups. This demonstrates that our modular and fully-automated algorithm helps improve the telescope system's limiting magnitude without compromising astrometric accuracy by enabling non-sidereal tracking on the target. This will help the NEO follow-up community cope with the accelerated discovery rates and improved sensitivity of the next-generation NEO surveys. Astreaks has been made available to the community under an open-source license. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2306.16519v1-abstract-full').style.display = 'none'; document.getElementById('2306.16519v1-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 June, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> June 2023. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">10 pages, 7 figures</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2306.10284">arXiv:2306.10284</a> <span> [<a href="https://arxiv.org/pdf/2306.10284">pdf</a>, <a href="https://arxiv.org/format/2306.10284">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/acef20">10.3847/2041-8213/acef20 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Far-Ultraviolet to Near-Infrared Observations of SN 2023ixf: A high energy explosion engulfed in complex circumstellar material </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Teja%2C+R+S">Rishabh Singh Teja</a>, <a href="/search/astro-ph?searchtype=author&query=Singh%2C+A">Avinash Singh</a>, <a href="/search/astro-ph?searchtype=author&query=Basu%2C+J">Judhajeet Basu</a>, <a href="/search/astro-ph?searchtype=author&query=Anupama%2C+G+C">G. C. Anupama</a>, <a href="/search/astro-ph?searchtype=author&query=Sahu%2C+D+K">D. K. Sahu</a>, <a href="/search/astro-ph?searchtype=author&query=Dutta%2C+A">Anirban Dutta</a>, <a href="/search/astro-ph?searchtype=author&query=Swain%2C+V">Vishwajeet Swain</a>, <a href="/search/astro-ph?searchtype=author&query=Nakaoka%2C+T">Tatsuya Nakaoka</a>, <a href="/search/astro-ph?searchtype=author&query=Pathak%2C+U">Utkarsh Pathak</a>, <a href="/search/astro-ph?searchtype=author&query=Bhalerao%2C+V">Varun Bhalerao</a>, <a href="/search/astro-ph?searchtype=author&query=Barway%2C+S">Sudhanshu Barway</a>, <a href="/search/astro-ph?searchtype=author&query=Kumar%2C+H">Harsh Kumar</a>, <a href="/search/astro-ph?searchtype=author&query=J.%2C+N+A">Nayana A. J.</a>, <a href="/search/astro-ph?searchtype=author&query=Imazawa%2C+R">Ryo Imazawa</a>, <a href="/search/astro-ph?searchtype=author&query=Kumar%2C+B">Brajesh Kumar</a>, <a href="/search/astro-ph?searchtype=author&query=Kawabata%2C+K+S">Koji S Kawabata</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2306.10284v2-abstract-short" style="display: inline;"> We present early-phase panchromatic photometric and spectroscopic coverage spanning far-ultraviolet (FUV) to the near-infrared (NIR) regime of the nearest hydrogen-rich core-collapse supernova in the last 25 years, SN 2023ixf. We observe early 'flash' features in the optical spectra due to a confined dense circumstellar material (CSM). We observe high-ionization absorption lines (FeII, MgII) in th… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2306.10284v2-abstract-full').style.display = 'inline'; document.getElementById('2306.10284v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2306.10284v2-abstract-full" style="display: none;"> We present early-phase panchromatic photometric and spectroscopic coverage spanning far-ultraviolet (FUV) to the near-infrared (NIR) regime of the nearest hydrogen-rich core-collapse supernova in the last 25 years, SN 2023ixf. We observe early 'flash' features in the optical spectra due to a confined dense circumstellar material (CSM). We observe high-ionization absorption lines (FeII, MgII) in the ultraviolet spectra from very early on. We also observe a multi-peaked emission profile of H-alpha in the spectrum beginning ~16 d, which indicates ongoing interaction of the SN ejecta with a pre-existing shell-shaped CSM having an inner radius of ~75 AU and an outer radius of ~140 AU. The shell-shaped CSM is likely a result of enhanced mass loss ~35-65 years before the explosion assuming a standard Red-Supergiant wind. The UV spectra are dominated by multiple highly ionized narrow absorption features and broad emission features from elements such as C, N, O, Si, Fe, and Ni. Based on early light curve models of Type II SNe, we infer that the nearby dense CSM confined to (7+-3)e14cm (~45 AU) is a result of enhanced mass loss (10^{-3.0+-0.5} Msol/yr) two decades before the explosion. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2306.10284v2-abstract-full').style.display = 'none'; document.getElementById('2306.10284v2-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 August, 2023; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 17 June, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> June 2023. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">Accepted for publication in ApJL (Revised, 3 figures and 1 table)</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> The Astrophysical Journal Letters, 954:L12 (10pp), 2023 September 1 </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2306.04057">arXiv:2306.04057</a> <span> [<a href="https://arxiv.org/pdf/2306.04057">pdf</a>, <a href="https://arxiv.org/format/2306.04057">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="High Energy Astrophysical Phenomena">astro-ph.HE</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Instrumentation and Methods for Astrophysics">astro-ph.IM</span> </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/ad118d">10.3847/2041-8213/ad118d <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> High hard X-ray polarization in Cygnus X-1 confined to the intermediate hard state: evidence for a variable jet component </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Chattopadhyay%2C+T">Tanmoy Chattopadhyay</a>, <a href="/search/astro-ph?searchtype=author&query=Kumar%2C+A">Abhay Kumar</a>, <a href="/search/astro-ph?searchtype=author&query=Rao%2C+A+R">A. R. Rao</a>, <a href="/search/astro-ph?searchtype=author&query=Bhargava%2C+Y">Yash Bhargava</a>, <a href="/search/astro-ph?searchtype=author&query=Vadawale%2C+S+V">Santosh V. Vadawale</a>, <a href="/search/astro-ph?searchtype=author&query=Ratheesh%2C+A">Ajay Ratheesh</a>, <a href="/search/astro-ph?searchtype=author&query=Dewangan%2C+G">Gulab Dewangan</a>, <a href="/search/astro-ph?searchtype=author&query=Bhattacharyay%2C+D">Dipankar Bhattacharyay</a>, <a href="/search/astro-ph?searchtype=author&query=S.%2C+M+N+P">Mithun N. P. S.</a>, <a href="/search/astro-ph?searchtype=author&query=Bhalerao%2C+V">Varun Bhalerao</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2306.04057v2-abstract-short" style="display: inline;"> Cygnus X-1, the well-known accreting black hole system, exhibits several observational features hinting at an intricate interplay between the accretion disk, its atmosphere known as the corona and the putative relativistic jet. It has been extensively studied using all available observational methods, including using the newly available technique of sensitive X-ray polarimetry. X-ray polarization… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2306.04057v2-abstract-full').style.display = 'inline'; document.getElementById('2306.04057v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2306.04057v2-abstract-full" style="display: none;"> Cygnus X-1, the well-known accreting black hole system, exhibits several observational features hinting at an intricate interplay between the accretion disk, its atmosphere known as the corona and the putative relativistic jet. It has been extensively studied using all available observational methods, including using the newly available technique of sensitive X-ray polarimetry. X-ray polarization characteristics are distinct for coronal and jet emissions. The low X-ray polarization measured below $\sim$100 keV is understood as arising from the corona. In contrast, the high polarization measurements reported above $\sim$400 keV required a separate jet-dominated spectral component, which spectroscopy does not demonstrate conclusively. Here we report precise polarization measurements in the 100-380 keV region made during three different sub-classes of spectral states of the source using the CZTI instrument onboard {\em AstroSat}. A high polarization (23$\pm$4 \%) is found mainly in the Intermediate Hard State of the source, and the energy-resolved measurements smoothly connect the coronal and the jet regimes. When high polarization is observed, the simultaneous spectral data hints at a separate power law component above 100 keV. We examine the possible sources of this energy-dependent high polarization in Cygnus X-1. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2306.04057v2-abstract-full').style.display = 'none'; document.getElementById('2306.04057v2-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 30 November, 2023; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 6 June, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> June 2023. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">Accepted for publication in ApJ Letters (ApJL)</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Astrophysical Journal Letters, Volume 960, Number 1, L2, 2023 December 29 </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2305.07068">arXiv:2305.07068</a> <span> [<a href="https://arxiv.org/pdf/2305.07068">pdf</a>, <a href="https://arxiv.org/ps/2305.07068">ps</a>, <a href="https://arxiv.org/format/2305.07068">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/acd541">10.3847/1538-4357/acd541 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Drop in the hard pulsed fraction and a candidate cyclotron line in IGR J16320-4751 seen by NuSTAR </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Bodaghee%2C+A">Arash Bodaghee</a>, <a href="/search/astro-ph?searchtype=author&query=Chiu%2C+A+J+-">Alan J. -L. Chiu</a>, <a href="/search/astro-ph?searchtype=author&query=Tomsick%2C+J+A">John A. Tomsick</a>, <a href="/search/astro-ph?searchtype=author&query=Bhalerao%2C+V">Varun Bhalerao</a>, <a href="/search/astro-ph?searchtype=author&query=Bottacini%2C+E">Eugenio Bottacini</a>, <a href="/search/astro-ph?searchtype=author&query=Clavel%2C+M">Maica Clavel</a>, <a href="/search/astro-ph?searchtype=author&query=Cox%2C+C">Cody Cox</a>, <a href="/search/astro-ph?searchtype=author&query=F%C3%BCrst%2C+F">Felix F眉rst</a>, <a href="/search/astro-ph?searchtype=author&query=Middleton%2C+M+J">Matthew J. Middleton</a>, <a href="/search/astro-ph?searchtype=author&query=Rahoui%2C+F">Farid Rahoui</a>, <a href="/search/astro-ph?searchtype=author&query=Rodriguez%2C+J">Jerome Rodriguez</a>, <a href="/search/astro-ph?searchtype=author&query=Romano%2C+P">Pat Romano</a>, <a href="/search/astro-ph?searchtype=author&query=Wilms%2C+J">Joern Wilms</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2305.07068v1-abstract-short" style="display: inline;"> We report on a timing and spectral analysis of a 50-ks NuSTAR observation of IGR J16320-4751 (= AX J1631.9-4752); a high-mass X-ray binary hosting a slowly-rotating neutron star. In this observation from 2015, the spin period was 1,308.8+/-0.4 s giving a period derivative dP/dt ~ 2E-8 s s-1 when compared with the period measured in 2004. In addition, the pulsed fraction decreased as a function of… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2305.07068v1-abstract-full').style.display = 'inline'; document.getElementById('2305.07068v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2305.07068v1-abstract-full" style="display: none;"> We report on a timing and spectral analysis of a 50-ks NuSTAR observation of IGR J16320-4751 (= AX J1631.9-4752); a high-mass X-ray binary hosting a slowly-rotating neutron star. In this observation from 2015, the spin period was 1,308.8+/-0.4 s giving a period derivative dP/dt ~ 2E-8 s s-1 when compared with the period measured in 2004. In addition, the pulsed fraction decreased as a function of energy, as opposed to the constant trend that was seen previously. This suggests a change in the accretion geometry of the system during the intervening 11 years. The phase-averaged spectra were fit with the typical model for accreting pulsars: a power law with an exponential cutoff. This left positive residuals at 6.4 keV attributable to the known iron K-alpha line, as well as negative residuals around 14 keV from a candidate cyclotron line detected at a significance of 5-sigma. We found no significant differences in the spectral parameters across the spin period, other than the expected changes in flux and component normalizations. A flare lasting around 5 ks was captured during the first half of the observation where the X-ray emission hardened and the local column density decreased. Finally, the binary orbital period was refined to 8.9912+/-0.0078 d thanks to Swift/BAT monitoring data from 2005-2022. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2305.07068v1-abstract-full').style.display = 'none'; document.getElementById('2305.07068v1-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 May, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> May 2023. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">17 pages, 11 figures, Referee-revised version 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/2303.12849">arXiv:2303.12849</a> <span> [<a href="https://arxiv.org/pdf/2303.12849">pdf</a>, <a href="https://arxiv.org/format/2303.12849">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/accf97">10.3847/2041-8213/accf97 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> A Sensitive Search for Supernova Emission Associated with the Extremely Energetic and Nearby GRB 221009A </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Srinivasaragavan%2C+G+P">Gokul P. Srinivasaragavan</a>, <a href="/search/astro-ph?searchtype=author&query=Connor%2C+B+O">Brendan O' Connor</a>, <a href="/search/astro-ph?searchtype=author&query=Cenko%2C+S+B">S. Bradley Cenko</a>, <a href="/search/astro-ph?searchtype=author&query=Dittmann%2C+A+J">Alexander J. Dittmann</a>, <a href="/search/astro-ph?searchtype=author&query=Yang%2C+S">Sheng Yang</a>, <a href="/search/astro-ph?searchtype=author&query=Sollerman%2C+J">Jesper Sollerman</a>, <a href="/search/astro-ph?searchtype=author&query=Anupama%2C+G+C">G. C. Anupama</a>, <a href="/search/astro-ph?searchtype=author&query=Barway%2C+S">Sudhanshu Barway</a>, <a href="/search/astro-ph?searchtype=author&query=Bhalerao%2C+V">Varun Bhalerao</a>, <a href="/search/astro-ph?searchtype=author&query=Kumar%2C+H">Harsh Kumar</a>, <a href="/search/astro-ph?searchtype=author&query=Swain%2C+V">Vishwajeet Swain</a>, <a href="/search/astro-ph?searchtype=author&query=Hammerstein%2C+E">Erica Hammerstein</a>, <a href="/search/astro-ph?searchtype=author&query=Holt%2C+I">Isiah Holt</a>, <a href="/search/astro-ph?searchtype=author&query=Anand%2C+S">Shreya Anand</a>, <a href="/search/astro-ph?searchtype=author&query=Andreoni%2C+I">Igor Andreoni</a>, <a href="/search/astro-ph?searchtype=author&query=Coughlin%2C+M+W">Michael W. Coughlin</a>, <a href="/search/astro-ph?searchtype=author&query=Dichiara%2C+S">Simone Dichiara</a>, <a href="/search/astro-ph?searchtype=author&query=Gal-Yam%2C+A">Avishay Gal-Yam</a>, <a href="/search/astro-ph?searchtype=author&query=Miller%2C+M+C">M. Coleman Miller</a>, <a href="/search/astro-ph?searchtype=author&query=Soon%2C+J">Jaime Soon</a>, <a href="/search/astro-ph?searchtype=author&query=Soria%2C+R">Roberto Soria</a>, <a href="/search/astro-ph?searchtype=author&query=Durbak%2C+J">Joseph Durbak</a>, <a href="/search/astro-ph?searchtype=author&query=Gillanders%2C+J+H">James H. Gillanders</a>, <a href="/search/astro-ph?searchtype=author&query=Laha%2C+S">Sibasish Laha</a>, <a href="/search/astro-ph?searchtype=author&query=Moore%2C+A+M">Anna M. Moore</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="2303.12849v3-abstract-short" style="display: inline;"> We report observations of the optical counterpart of the long gamma-ray burst (LGRB) GRB 221009A. Due to the extreme rarity of being both nearby ($z = 0.151$) and highly energetic ($E_{纬,\mathrm{iso}} \geq 10^{54}$ erg), GRB 221009A offers a unique opportunity to probe the connection between massive star core collapse and relativistic jet formation across a very broad range of $纬$-ray properties.… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2303.12849v3-abstract-full').style.display = 'inline'; document.getElementById('2303.12849v3-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2303.12849v3-abstract-full" style="display: none;"> We report observations of the optical counterpart of the long gamma-ray burst (LGRB) GRB 221009A. Due to the extreme rarity of being both nearby ($z = 0.151$) and highly energetic ($E_{纬,\mathrm{iso}} \geq 10^{54}$ erg), GRB 221009A offers a unique opportunity to probe the connection between massive star core collapse and relativistic jet formation across a very broad range of $纬$-ray properties. Adopting a phenomenological power-law model for the afterglow and host galaxy estimates from high-resolution Hubble Space Telescope imaging, we use Bayesian model comparison techniques to determine the likelihood of an associated SN contributing excess flux to the optical light curve. Though not conclusive, we find moderate evidence ($K_{\rm{Bayes}}=10^{1.2}$) for the presence of an additional component arising from an associated supernova, SN 2022xiw, and find that it must be substantially fainter ($<$ 67% as bright at the 99% confidence interval) than SN 1998bw. Given the large and uncertain line-of-sight extinction, we attempt to constrain the supernova parameters ($M_{\mathrm{Ni}}$, $M_{\mathrm{ej}}$, and $E_{\mathrm{KE}}$) under several different assumptions with respect to the host galaxy's extinction. We find properties that are broadly consistent with previous GRB-associated SNe: $M_{\rm{Ni}}=0.05$ - $0.25 \, \rm{M_\odot}$, $M_{\rm{ej}}=3.5$ - $11.1 \, \rm{M_\odot}$, and $E_{\rm{KE}} = (1.6$ - $5.2) \times 10^{52} \, \rm{erg}$. We note that these properties are weakly constrained due to the faintness of the supernova with respect to the afterglow and host emission, but we do find a robust upper limit on the $M_{\rm{Ni}}$ of $M_{\rm{Ni}}<0.36\, \rm{M_\odot}$. Given the tremendous range in isotropic gamma-ray energy release exhibited by GRBs (7 orders of magnitude), the SN emission appears to be decoupled from the central engine in these systems. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2303.12849v3-abstract-full').style.display = 'none'; document.getElementById('2303.12849v3-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 May, 2023; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 22 March, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> March 2023. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">18 pages, accepted to ApJL, 4 tables, 5 figures. Updated abstract in Preview</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2211.16530">arXiv:2211.16530</a> <span> [<a href="https://arxiv.org/pdf/2211.16530">pdf</a>, <a href="https://arxiv.org/format/2211.16530">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/10.1038/s41586-022-05465-8">10.1038/s41586-022-05465-8 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> A very luminous jet from the disruption of a star by a massive black hole </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Andreoni%2C+I">Igor Andreoni</a>, <a href="/search/astro-ph?searchtype=author&query=Coughlin%2C+M+W">Michael W. Coughlin</a>, <a href="/search/astro-ph?searchtype=author&query=Perley%2C+D+A">Daniel A. Perley</a>, <a href="/search/astro-ph?searchtype=author&query=Yao%2C+Y">Yuhan Yao</a>, <a href="/search/astro-ph?searchtype=author&query=Lu%2C+W">Wenbin Lu</a>, <a href="/search/astro-ph?searchtype=author&query=Cenko%2C+S+B">S. Bradley Cenko</a>, <a href="/search/astro-ph?searchtype=author&query=Kumar%2C+H">Harsh Kumar</a>, <a href="/search/astro-ph?searchtype=author&query=Anand%2C+S">Shreya Anand</a>, <a href="/search/astro-ph?searchtype=author&query=Ho%2C+A+Y+Q">Anna Y. Q. Ho</a>, <a href="/search/astro-ph?searchtype=author&query=Kasliwal%2C+M+M">Mansi M. Kasliwal</a>, <a href="/search/astro-ph?searchtype=author&query=Postigo%2C+A+d+U">Antonio de Ugarte Postigo</a>, <a href="/search/astro-ph?searchtype=author&query=Sagues-Carracedo%2C+A">Ana Sagues-Carracedo</a>, <a href="/search/astro-ph?searchtype=author&query=Schulze%2C+S">Steve Schulze</a>, <a href="/search/astro-ph?searchtype=author&query=Kann%2C+D+A">D. Alexander Kann</a>, <a href="/search/astro-ph?searchtype=author&query=Kulkarni%2C+S+R">S. R. Kulkarni</a>, <a href="/search/astro-ph?searchtype=author&query=Sollerman%2C+J">Jesper Sollerman</a>, <a href="/search/astro-ph?searchtype=author&query=Tanvir%2C+N">Nial Tanvir</a>, <a href="/search/astro-ph?searchtype=author&query=Rest%2C+A">Armin Rest</a>, <a href="/search/astro-ph?searchtype=author&query=Izzo%2C+L">Luca Izzo</a>, <a href="/search/astro-ph?searchtype=author&query=Somalwar%2C+J+J">Jean J. Somalwar</a>, <a href="/search/astro-ph?searchtype=author&query=Kaplan%2C+D+L">David L. Kaplan</a>, <a href="/search/astro-ph?searchtype=author&query=Ahumada%2C+T">Tomas Ahumada</a>, <a href="/search/astro-ph?searchtype=author&query=Anupama%2C+G+C">G. C. Anupama</a>, <a href="/search/astro-ph?searchtype=author&query=Auchettl%2C+K">Katie Auchettl</a>, <a href="/search/astro-ph?searchtype=author&query=Barway%2C+S">Sudhanshu Barway</a> , et al. (56 additional authors not shown) </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2211.16530v1-abstract-short" style="display: inline;"> Tidal disruption events (TDEs) are bursts of electromagnetic energy released when supermassive black holes (SMBHs) at the centers of galaxies violently disrupt a star that passes too close. TDEs provide a new window to study accretion onto SMBHs; in some rare cases, this accretion leads to launching of a relativistic jet, but the necessary conditions are not fully understood. The best studied jett… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2211.16530v1-abstract-full').style.display = 'inline'; document.getElementById('2211.16530v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2211.16530v1-abstract-full" style="display: none;"> Tidal disruption events (TDEs) are bursts of electromagnetic energy released when supermassive black holes (SMBHs) at the centers of galaxies violently disrupt a star that passes too close. TDEs provide a new window to study accretion onto SMBHs; in some rare cases, this accretion leads to launching of a relativistic jet, but the necessary conditions are not fully understood. The best studied jetted TDE to date is Swift J1644+57, which was discovered in gamma-rays, but was too obscured by dust to be seen at optical wavelengths. Here we report the optical discovery of AT2022cmc, a rapidly fading source at cosmological distance (redshift z=1.19325) whose unique lightcurve transitioned into a luminous plateau within days. Observations of a bright counterpart at other wavelengths, including X-rays, sub-millimeter, and radio, supports the interpretation of AT2022cmc as a jetted TDE containing a synchrotron "afterglow", likely launched by a SMBH with spin $a \gtrsim 0.3$. Using 4 years of Zwicky Transient Facility (ZTF) survey data, we calculate a rate of $0.02 ^{+ 0.04 }_{- 0.01 }$ Gpc$^{-3}$ yr$^{-1}$ for on-axis jetted TDEs based on the luminous, fast-fading red component, thus providing a measurement complementary to the rates derived from X-ray and radio observations. Correcting for the beaming angle effects, this rate confirms that about 1% of TDEs have relativistic jets. Optical surveys can use AT2022cmc as a prototype to unveil a population of jetted TDEs. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2211.16530v1-abstract-full').style.display = 'none'; document.getElementById('2211.16530v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 29 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">Accepted for publication in Nature</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2211.12055">arXiv:2211.12055</a> <span> [<a href="https://arxiv.org/pdf/2211.12055">pdf</a>, <a href="https://arxiv.org/format/2211.12055">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"> Daksha: On Alert for High Energy Transients </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Bhalerao%2C+V">Varun Bhalerao</a>, <a href="/search/astro-ph?searchtype=author&query=Vadawale%2C+S">Santosh Vadawale</a>, <a href="/search/astro-ph?searchtype=author&query=Tendulkar%2C+S">Shriharsh Tendulkar</a>, <a href="/search/astro-ph?searchtype=author&query=Bhattacharya%2C+D">Dipankar Bhattacharya</a>, <a href="/search/astro-ph?searchtype=author&query=Rana%2C+V">Vikram Rana</a>, <a href="/search/astro-ph?searchtype=author&query=Adalja%2C+H+K+L">Hitesh Kumar L. Adalja</a>, <a href="/search/astro-ph?searchtype=author&query=Belatikar%2C+H">Hrishikesh Belatikar</a>, <a href="/search/astro-ph?searchtype=author&query=Bhaganagare%2C+M">Mahesh Bhaganagare</a>, <a href="/search/astro-ph?searchtype=author&query=Dewangan%2C+G">Gulab Dewangan</a>, <a href="/search/astro-ph?searchtype=author&query=Ghodgaonkar%2C+A">Abhijeet Ghodgaonkar</a>, <a href="/search/astro-ph?searchtype=author&query=Goyal%2C+S+K">Shiv Kumar Goyal</a>, <a href="/search/astro-ph?searchtype=author&query=Gunasekaran%2C+S">Suresh Gunasekaran</a>, <a href="/search/astro-ph?searchtype=author&query=Guruprasad%2C+P+J">P J Guruprasad</a>, <a href="/search/astro-ph?searchtype=author&query=Koyande%2C+J+G">Jayprakash G. Koyande</a>, <a href="/search/astro-ph?searchtype=author&query=Kulkarni%2C+S">Salil Kulkarni</a>, <a href="/search/astro-ph?searchtype=author&query=Kutty%2C+A">APK Kutty</a>, <a href="/search/astro-ph?searchtype=author&query=Ladiya%2C+T">Tinkal Ladiya</a>, <a href="/search/astro-ph?searchtype=author&query=Marla%2C+D">Deepak Marla</a>, <a href="/search/astro-ph?searchtype=author&query=Mate%2C+S">Sujay Mate</a>, <a href="/search/astro-ph?searchtype=author&query=Mithun%2C+N+P+S">N. P. S. Mithun</a>, <a href="/search/astro-ph?searchtype=author&query=Mote%2C+R">Rakesh Mote</a>, <a href="/search/astro-ph?searchtype=author&query=Narang%2C+S">Sanjoli Narang</a>, <a href="/search/astro-ph?searchtype=author&query=Nema%2C+A">Ayush Nema</a>, <a href="/search/astro-ph?searchtype=author&query=Nimbalkar%2C+S">Sudhanshu Nimbalkar</a>, <a href="/search/astro-ph?searchtype=author&query=Pai%2C+A">Archana Pai</a> , et al. (23 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="2211.12055v2-abstract-short" style="display: inline;"> We present Daksha, a proposed high energy transients mission for the study of electromagnetic counterparts of gravitational wave sources, and gamma ray bursts. Daksha will comprise of two satellites in low earth equatorial orbits, on opposite sides of earth. Each satellite will carry three types of detectors to cover the entire sky in an energy range from 1 keV to >1 MeV. Any transients detected o… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2211.12055v2-abstract-full').style.display = 'inline'; document.getElementById('2211.12055v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2211.12055v2-abstract-full" style="display: none;"> We present Daksha, a proposed high energy transients mission for the study of electromagnetic counterparts of gravitational wave sources, and gamma ray bursts. Daksha will comprise of two satellites in low earth equatorial orbits, on opposite sides of earth. Each satellite will carry three types of detectors to cover the entire sky in an energy range from 1 keV to >1 MeV. Any transients detected on-board will be announced publicly within minutes of discovery. All photon data will be downloaded in ground station passes to obtain source positions, spectra, and light curves. In addition, Daksha will address a wide range of science cases including monitoring X-ray pulsars, studies of magnetars, solar flares, searches for fast radio burst counterparts, routine monitoring of bright persistent high energy sources, terrestrial gamma-ray flashes, and probing primordial black hole abundances through lensing. In this paper, we discuss the technical capabilities of Daksha, while the detailed science case is discussed in a separate paper. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2211.12055v2-abstract-full').style.display = 'none'; document.getElementById('2211.12055v2-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 January, 2024; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 22 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">9 pages, 3 figures, 1 table. Accepted in Experimental Astronomy. Additional information about the mission is available at https://www.dakshasat.in/</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2211.12052">arXiv:2211.12052</a> <span> [<a href="https://arxiv.org/pdf/2211.12052">pdf</a>, <a href="https://arxiv.org/format/2211.12052">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="High Energy Astrophysical Phenomena">astro-ph.HE</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Instrumentation and Methods for Astrophysics">astro-ph.IM</span> </div> </div> <p class="title is-5 mathjax"> Science with the Daksha High Energy Transients Mission </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Bhalerao%2C+V">Varun Bhalerao</a>, <a href="/search/astro-ph?searchtype=author&query=Sawant%2C+D">Disha Sawant</a>, <a href="/search/astro-ph?searchtype=author&query=Pai%2C+A">Archana Pai</a>, <a href="/search/astro-ph?searchtype=author&query=Tendulkar%2C+S">Shriharsh Tendulkar</a>, <a href="/search/astro-ph?searchtype=author&query=Vadawale%2C+S">Santosh Vadawale</a>, <a href="/search/astro-ph?searchtype=author&query=Bhattacharya%2C+D">Dipankar Bhattacharya</a>, <a href="/search/astro-ph?searchtype=author&query=Rana%2C+V">Vikram Rana</a>, <a href="/search/astro-ph?searchtype=author&query=Adalja%2C+H+K+L">Hitesh Kumar L. Adalja</a>, <a href="/search/astro-ph?searchtype=author&query=Anupama%2C+G+C">G C Anupama</a>, <a href="/search/astro-ph?searchtype=author&query=Bala%2C+S">Suman Bala</a>, <a href="/search/astro-ph?searchtype=author&query=Banerjee%2C+S">Smaranika Banerjee</a>, <a href="/search/astro-ph?searchtype=author&query=Basu%2C+J">Judhajeet Basu</a>, <a href="/search/astro-ph?searchtype=author&query=Belatikar%2C+H">Hrishikesh Belatikar</a>, <a href="/search/astro-ph?searchtype=author&query=Beniamini%2C+P">Paz Beniamini</a>, <a href="/search/astro-ph?searchtype=author&query=Bhaganagare%2C+M">Mahesh Bhaganagare</a>, <a href="/search/astro-ph?searchtype=author&query=Bhaskar%2C+A">Ankush Bhaskar</a>, <a href="/search/astro-ph?searchtype=author&query=Bhattacharjee%2C+S">Soumyadeep Bhattacharjee</a>, <a href="/search/astro-ph?searchtype=author&query=Bose%2C+S">Sukanta Bose</a>, <a href="/search/astro-ph?searchtype=author&query=Cenko%2C+B">Brad Cenko</a>, <a href="/search/astro-ph?searchtype=author&query=Chanda%2C+M+V">Mehul Vijay Chanda</a>, <a href="/search/astro-ph?searchtype=author&query=Dewangan%2C+G">Gulab Dewangan</a>, <a href="/search/astro-ph?searchtype=author&query=Dixit%2C+V">Vishal Dixit</a>, <a href="/search/astro-ph?searchtype=author&query=Dutta%2C+A">Anirban Dutta</a>, <a href="/search/astro-ph?searchtype=author&query=Gawade%2C+P">Priyanka Gawade</a>, <a href="/search/astro-ph?searchtype=author&query=Ghodgaonkar%2C+A">Abhijeet Ghodgaonkar</a> , et al. (50 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="2211.12052v2-abstract-short" style="display: inline;"> We present the science case for the proposed Daksha high energy transients mission. Daksha will comprise of two satellites covering the entire sky from 1~keV to $>1$~MeV. The primary objectives of the mission are to discover and characterize electromagnetic counterparts to gravitational wave source; and to study Gamma Ray Bursts (GRBs). Daksha is a versatile all-sky monitor that can address a wide… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2211.12052v2-abstract-full').style.display = 'inline'; document.getElementById('2211.12052v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2211.12052v2-abstract-full" style="display: none;"> We present the science case for the proposed Daksha high energy transients mission. Daksha will comprise of two satellites covering the entire sky from 1~keV to $>1$~MeV. The primary objectives of the mission are to discover and characterize electromagnetic counterparts to gravitational wave source; and to study Gamma Ray Bursts (GRBs). Daksha is a versatile all-sky monitor that can address a wide variety of science cases. With its broadband spectral response, high sensitivity, and continuous all-sky coverage, it will discover fainter and rarer sources than any other existing or proposed mission. Daksha can make key strides in GRB research with polarization studies, prompt soft spectroscopy, and fine time-resolved spectral studies. Daksha will provide continuous monitoring of X-ray pulsars. It will detect magnetar outbursts and high energy counterparts to Fast Radio Bursts. Using Earth occultation to measure source fluxes, the two satellites together will obtain daily flux measurements of bright hard X-ray sources including active galactic nuclei, X-ray binaries, and slow transients like Novae. Correlation studies between the two satellites can be used to probe primordial black holes through lensing. Daksha will have a set of detectors continuously pointing towards the Sun, providing excellent hard X-ray monitoring data. Closer to home, the high sensitivity and time resolution of Daksha can be leveraged for the characterization of Terrestrial Gamma-ray Flashes. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2211.12052v2-abstract-full').style.display = 'none'; document.getElementById('2211.12052v2-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 January, 2024; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 22 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">19 pages, 7 figures. Accepted in Experimental Astronomy. More details about the mission at https://www.dakshasat.in/</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2210.02389">arXiv:2210.02389</a> <span> [<a href="https://arxiv.org/pdf/2210.02389">pdf</a>, <a href="https://arxiv.org/format/2210.02389">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/10.1093/mnras/stac2901">10.1093/mnras/stac2901 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Timing and spectral studies of Cen X-3 in multiple luminosity states using $\textit{AstroSat}$ </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Bachhar%2C+R">Ritesh Bachhar</a>, <a href="/search/astro-ph?searchtype=author&query=Raman%2C+G">Gayathri Raman</a>, <a href="/search/astro-ph?searchtype=author&query=Bhalerao%2C+V">Varun Bhalerao</a>, <a href="/search/astro-ph?searchtype=author&query=Bhattacharya%2C+D">Dipankar Bhattacharya</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="2210.02389v1-abstract-short" style="display: inline;"> We present the results of timing and spectral analysis of the HMXB pulsar, Cen X-3, with the help of observations carried out using the Large Area X-ray Proportional Counter (LAXPC) on board $\textit{AstroSat}$. As part of our analysis, we sampled the source properties during 4 different observation epochs covering two widely different intensity states. We obtain a timing solution and report preci… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2210.02389v1-abstract-full').style.display = 'inline'; document.getElementById('2210.02389v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2210.02389v1-abstract-full" style="display: none;"> We present the results of timing and spectral analysis of the HMXB pulsar, Cen X-3, with the help of observations carried out using the Large Area X-ray Proportional Counter (LAXPC) on board $\textit{AstroSat}$. As part of our analysis, we sampled the source properties during 4 different observation epochs covering two widely different intensity states. We obtain a timing solution and report precise measurements of the spin and orbital parameters corresponding to these observational epochs. The pulse profiles during the two intensity states reveal dramatically varying shapes within a time span of one month. We report the detection of one of the lowest measured frequencies of quasi-periodic oscillations (QPO) at 0.026$\pm$0.001 Hz for Cen X-3 during its low-intensity state. We also find correlated periodic and aperiodic noise components in the power density spectra. We further carried out a phase averaged and a pulse phase resolved spectral study, where we find that the best fit continuum spectrum is well described by an absorbed comptonization model along with a blackbody. Cen X-3 exhibited the presence of the $\sim$28 keV CRSF absorption line and a $\sim$6.6 keV Fe emission line in both the intensity states. Significant variations in the line forming regions and mode of accretion for Cen X-3 within time spans of a month make Cen X-3 a highly dynamic persistent binary. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2210.02389v1-abstract-full').style.display = 'none'; document.getElementById('2210.02389v1-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 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">14 pages, 8 figures, 2 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/2209.02077">arXiv:2209.02077</a> <span> [<a href="https://arxiv.org/pdf/2209.02077">pdf</a>, <a href="https://arxiv.org/format/2209.02077">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="High Energy Astrophysical Phenomena">astro-ph.HE</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Instrumentation and Methods for Astrophysics">astro-ph.IM</span> </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/stac2516">10.1093/mnras/stac2516 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> GROWTH on S190426c II: GROWTH-India Telescope search for an optical counterpart with a custom image reduction and candidate vetting pipeline </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Kumar%2C+H">Harsh Kumar</a>, <a href="/search/astro-ph?searchtype=author&query=Bhalerao%2C+V">Varun Bhalerao</a>, <a href="/search/astro-ph?searchtype=author&query=Anupama%2C+G+C">G. C. Anupama</a>, <a href="/search/astro-ph?searchtype=author&query=Barway%2C+S">Sudhanshu Barway</a>, <a href="/search/astro-ph?searchtype=author&query=Coughlin%2C+M+W">Michael W. Coughlin</a>, <a href="/search/astro-ph?searchtype=author&query=De%2C+K">Kishalay De</a>, <a href="/search/astro-ph?searchtype=author&query=Deshmukh%2C+K">Kunal Deshmukh</a>, <a href="/search/astro-ph?searchtype=author&query=Dutta%2C+A">Anirban Dutta</a>, <a href="/search/astro-ph?searchtype=author&query=Goldstein%2C+D+A">Daniel A Goldstein</a>, <a href="/search/astro-ph?searchtype=author&query=Jassani%2C+A">Adeem Jassani</a>, <a href="/search/astro-ph?searchtype=author&query=Joharle%2C+S">Simran Joharle</a>, <a href="/search/astro-ph?searchtype=author&query=Karambelker%2C+V">Viraj Karambelker</a>, <a href="/search/astro-ph?searchtype=author&query=Khandagale%2C+M">Maitreya Khandagale</a>, <a href="/search/astro-ph?searchtype=author&query=Kumar%2C+B">Brajesh Kumar</a>, <a href="/search/astro-ph?searchtype=author&query=Saraogi%2C+D">Divita Saraogi</a>, <a href="/search/astro-ph?searchtype=author&query=Sharma%2C+Y">Yashvi Sharma</a>, <a href="/search/astro-ph?searchtype=author&query=Shenoy%2C+V">Vedant Shenoy</a>, <a href="/search/astro-ph?searchtype=author&query=singer%2C+L">Leo singer</a>, <a href="/search/astro-ph?searchtype=author&query=Singh%2C+A">Avinash Singh</a>, <a href="/search/astro-ph?searchtype=author&query=Waratkar%2C+G">Gaurav Waratkar</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="2209.02077v1-abstract-short" style="display: inline;"> S190426c / GW190426_152155 was the first probable neutron star - black hole merger candidate detected by the LIGO-Virgo Collaboration. We undertook a tiled search for optical counterparts of this event using the 0.7m GROWTH-India Telescope. Over a period of two weeks, we obtained multiple observations over a 22.1 deg^2 area, with a 17.5% probability of containing the source location. Initial effor… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2209.02077v1-abstract-full').style.display = 'inline'; document.getElementById('2209.02077v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2209.02077v1-abstract-full" style="display: none;"> S190426c / GW190426_152155 was the first probable neutron star - black hole merger candidate detected by the LIGO-Virgo Collaboration. We undertook a tiled search for optical counterparts of this event using the 0.7m GROWTH-India Telescope. Over a period of two weeks, we obtained multiple observations over a 22.1 deg^2 area, with a 17.5% probability of containing the source location. Initial efforts included obtaining photometry of sources reported by various groups, and a visual search for sources in all galaxies contained in the region. Subsequently, we have developed an image subtraction and candidate vetting pipeline with ~ 94% efficiency for transient detection. Processing the data with this pipeline, we find several transients, but none that are compatible with kilonova models. We present the details of our observations, working of our pipeline, results from the search, and our interpretations of the non-detections that will work as a pathfinder during the O4 run of LVK. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2209.02077v1-abstract-full').style.display = 'none'; document.getElementById('2209.02077v1-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, 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">12 pages, 6 figures, Accepted for publication in Monthly Notices of the Royal Astronomical Society</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2209.00222">arXiv:2209.00222</a> <span> [<a href="https://arxiv.org/pdf/2209.00222">pdf</a>, <a href="https://arxiv.org/format/2209.00222">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"> Experimental verification of off-axis polarimetry with Cadmium Zinc Telluride detectors of AstroSat-CZT Imager </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Vaishnava%2C+C+S">C. S. Vaishnava</a>, <a href="/search/astro-ph?searchtype=author&query=Mithun%2C+N+P+S">N. P. S. Mithun</a>, <a href="/search/astro-ph?searchtype=author&query=Vadawale%2C+S+V">Santosh V. Vadawale</a>, <a href="/search/astro-ph?searchtype=author&query=Aarthy%2C+E">Esakkiappan Aarthy</a>, <a href="/search/astro-ph?searchtype=author&query=Patel%2C+A+R">Arpit R. Patel</a>, <a href="/search/astro-ph?searchtype=author&query=Adalja%2C+H+L">Hiteshkumar L. Adalja</a>, <a href="/search/astro-ph?searchtype=author&query=Tiwari%2C+N+K">Neeraj Kumar Tiwari</a>, <a href="/search/astro-ph?searchtype=author&query=Ladiya%2C+T">Tinkal Ladiya</a>, <a href="/search/astro-ph?searchtype=author&query=Navale%2C+N">Nilam Navale</a>, <a href="/search/astro-ph?searchtype=author&query=Chattopadhyay%2C+T">Tanmoy Chattopadhyay</a>, <a href="/search/astro-ph?searchtype=author&query=Rao%2C+A+R">A. R. Rao</a>, <a href="/search/astro-ph?searchtype=author&query=Bhalerao%2C+V">Varun Bhalerao</a>, <a href="/search/astro-ph?searchtype=author&query=Bhattacharya%2C+D">Dipankar Bhattacharya</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="2209.00222v1-abstract-short" style="display: inline;"> The Cadmium Zinc Telluride Imager (CZTI) onboard AstroSat consists of an array of a large number of pixellated CZT detectors capable of measuring the polarization of incident hard X-rays. The polarization measurement capability of CZTI for on-axis sources was experimentally confirmed before the launch. CZTI has yielded tantalizing results on the X-ray polarization of the Crab nebula and pulsar in… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2209.00222v1-abstract-full').style.display = 'inline'; document.getElementById('2209.00222v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2209.00222v1-abstract-full" style="display: none;"> The Cadmium Zinc Telluride Imager (CZTI) onboard AstroSat consists of an array of a large number of pixellated CZT detectors capable of measuring the polarization of incident hard X-rays. The polarization measurement capability of CZTI for on-axis sources was experimentally confirmed before the launch. CZTI has yielded tantalizing results on the X-ray polarization of the Crab nebula and pulsar in the energy range of 100 - 380 keV. CZTI has also contributed to the measurement of prompt emission polarization for several Gamma-Ray Bursts (GRBs). However, polarization measurements of off-axis sources like GRBs are challenging. It is vital to experimentally calibrate the CZTI sensitivity to off-axis sources to enhance the credence of the measurements. In this context, we report the verification of the off-axis polarimetric capability of pixellated CZT detectors through the controlled experiments carried out with a CZT detector similar to that used in CZTI and extensive Geant4 simulations of the experimental set-up. Our current results show that the CZT detectors can be used to measure the polarization of bright GRBs up to off-axis angles of ~60 degrees. However, at incidence angles between 45-60 degrees, there might be some systematic effects which needs to be taken into account while interpreting the measured polarisation fraction. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2209.00222v1-abstract-full').style.display = 'none'; document.getElementById('2209.00222v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 1 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">Accepted for publication in JATIS</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2208.14520">arXiv:2208.14520</a> <span> [<a href="https://arxiv.org/pdf/2208.14520">pdf</a>, <a href="https://arxiv.org/format/2208.14520">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="Instrumentation and Methods for Astrophysics">astro-ph.IM</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.3847/1538-3881/ac8dee">10.3847/1538-3881/ac8dee <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Utilizing a global network of telescopes to update the ephemeris for the highly eccentric planet HD 80606 b and to ensure the efficient scheduling of JWST </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Pearson%2C+K+A">Kyle A. Pearson</a>, <a href="/search/astro-ph?searchtype=author&query=Beichman%2C+C">Chas Beichman</a>, <a href="/search/astro-ph?searchtype=author&query=Fulton%2C+B+J">Benjamin J. Fulton</a>, <a href="/search/astro-ph?searchtype=author&query=Esposito%2C+T+M">Thomas M. Esposito</a>, <a href="/search/astro-ph?searchtype=author&query=Zellem%2C+R+T">Robert T. Zellem</a>, <a href="/search/astro-ph?searchtype=author&query=Ciardi%2C+D+R">David R. Ciardi</a>, <a href="/search/astro-ph?searchtype=author&query=Rolfness%2C+J">Jonah Rolfness</a>, <a href="/search/astro-ph?searchtype=author&query=Engelke%2C+J">John Engelke</a>, <a href="/search/astro-ph?searchtype=author&query=Fatahi%2C+T">Tamim Fatahi</a>, <a href="/search/astro-ph?searchtype=author&query=Zimmerman-Brachman%2C+R">Rachel Zimmerman-Brachman</a>, <a href="/search/astro-ph?searchtype=author&query=Avsar%2C+A">Arin Avsar</a>, <a href="/search/astro-ph?searchtype=author&query=Bhalerao%2C+V">Varun Bhalerao</a>, <a href="/search/astro-ph?searchtype=author&query=Boyce%2C+P">Pat Boyce</a>, <a href="/search/astro-ph?searchtype=author&query=Bretton%2C+M">Marc Bretton</a>, <a href="/search/astro-ph?searchtype=author&query=Burnett%2C+A+D">Alexandra D. Burnett</a>, <a href="/search/astro-ph?searchtype=author&query=Burt%2C+J">Jennifer Burt</a>, <a href="/search/astro-ph?searchtype=author&query=Fowler%2C+M">Martin Fowler</a>, <a href="/search/astro-ph?searchtype=author&query=Gallego%2C+D">Daniel Gallego</a>, <a href="/search/astro-ph?searchtype=author&query=Gomez%2C+E">Edward Gomez</a>, <a href="/search/astro-ph?searchtype=author&query=Guillet%2C+B">Bruno Guillet</a>, <a href="/search/astro-ph?searchtype=author&query=Hilburn%2C+J">Jerry Hilburn</a>, <a href="/search/astro-ph?searchtype=author&query=Jongen%2C+Y">Yves Jongen</a>, <a href="/search/astro-ph?searchtype=author&query=Kataria%2C+T">Tiffany Kataria</a>, <a href="/search/astro-ph?searchtype=author&query=Kokori%2C+A">Anastasia Kokori</a>, <a href="/search/astro-ph?searchtype=author&query=Kumar%2C+H">Harsh Kumar</a> , et al. (15 additional authors not shown) </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2208.14520v1-abstract-short" style="display: inline;"> The transiting planet HD80606b undergoes a 1000-fold increase in insolation during its 111-day orbit due to it being highly eccentric (e=0.93). The planet's effective temperature increases from 400K to over 1400K in a few hours as it makes a rapid passage to within 0.03AU of its host star during periapsis. Spectroscopic observations during the eclipse (which is conveniently oriented a few hours be… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2208.14520v1-abstract-full').style.display = 'inline'; document.getElementById('2208.14520v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2208.14520v1-abstract-full" style="display: none;"> The transiting planet HD80606b undergoes a 1000-fold increase in insolation during its 111-day orbit due to it being highly eccentric (e=0.93). The planet's effective temperature increases from 400K to over 1400K in a few hours as it makes a rapid passage to within 0.03AU of its host star during periapsis. Spectroscopic observations during the eclipse (which is conveniently oriented a few hours before periapsis) of HD80606b with the James Webb Space Telescope (JWST) are poised to exploit this highly variable environment to study a wide variety of atmospheric properties, including composition, chemical and dynamical timescales, and large scale atmospheric motions. Critical to planning and interpreting these observations is an accurate knowledge of the planet's orbit. We report on observations of two full-transit events: 7 February 2020 as observed by the TESS spacecraft and 7--8 December 2021 as observed with a worldwide network of small telescopes. We also report new radial velocity observations which when analyzed with a coupled model to the transits greatly improve the planet's orbital ephemeris. Our new orbit solution reduces the uncertainty in the transit and eclipse timing of the JWST era from tens of minutes to a few minutes. When combined with the planned JWST observations, this new precision may be adequate to look for non-Keplerian effects in the orbit of HD80606b. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2208.14520v1-abstract-full').style.display = 'none'; document.getElementById('2208.14520v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 30 August, 2022; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> August 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 AJ; 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/2208.11476">arXiv:2208.11476</a> <span> [<a href="https://arxiv.org/pdf/2208.11476">pdf</a>, <a href="https://arxiv.org/format/2208.11476">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Instrumentation and Methods for Astrophysics">astro-ph.IM</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="High Energy Astrophysical Phenomena">astro-ph.HE</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1093/mnras/stac2466">10.1093/mnras/stac2466 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Extending the energy range of AstroSat-CZTI up to 380 keV with Compton Spectroscopy </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Kumar%2C+A">Abhay Kumar</a>, <a href="/search/astro-ph?searchtype=author&query=Chattopadhyay%2C+T">Tanmoy Chattopadhyay</a>, <a href="/search/astro-ph?searchtype=author&query=Vadawale%2C+S+V">Santosh V. Vadawale</a>, <a href="/search/astro-ph?searchtype=author&query=Rao%2C+A+R">A. R. Rao</a>, <a href="/search/astro-ph?searchtype=author&query=S.%2C+M+N+P">Mithun N. P. S.</a>, <a href="/search/astro-ph?searchtype=author&query=Bhalerao%2C+V">Varun Bhalerao</a>, <a href="/search/astro-ph?searchtype=author&query=Bhattacharya%2C+D">Dipankar Bhattacharya</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="2208.11476v1-abstract-short" style="display: inline;"> The CZTI (Cadmium Zinc Telluride Imager) onboard AstroSat is a high energy coded mask imager and spectrometer in the energy range of 20 - 100 keV. Above 100 keV, the dominance of Compton scattering cross-section in CZTI results in a significant number of 2-pixel Compton events and these have been successfully utilized for polarization analysis of Crab pulsar and nebula (and transients like Gamma-r… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2208.11476v1-abstract-full').style.display = 'inline'; document.getElementById('2208.11476v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2208.11476v1-abstract-full" style="display: none;"> The CZTI (Cadmium Zinc Telluride Imager) onboard AstroSat is a high energy coded mask imager and spectrometer in the energy range of 20 - 100 keV. Above 100 keV, the dominance of Compton scattering cross-section in CZTI results in a significant number of 2-pixel Compton events and these have been successfully utilized for polarization analysis of Crab pulsar and nebula (and transients like Gamma-ray bursts) in 100 - 380 keV. These 2-pixel Compton events can also be used to extend the spectroscopic energy range of CZTI up to 380 keV for bright sources. However, unlike the spectroscopy in primary energy range, where simultaneous background measurement is available from masked pixels, Compton spectroscopy requires blank sky observation for background measurement. Background subtraction, in this case, is non-trivial because of the presence of both short-term and long-term temporal variations in the data, which depend on multiple factors like earth rotation and the effect of South Atlantic Anomaly (SAA) regions etc. We have developed a methodology of background selection and subtraction that takes into account for these effects. Here, we describe these background selection and subtraction techniques and validate them using spectroscopy of Crab in the extended energy range of 30 - 380 keV region, and compare the obtained spectral parameters with the INTEGRAL results. This new capability allows for the extension of the energy range of AstroSat spectroscopy and will also enable the simultaneous spectro-polarimetric study of other bright sources like Cygnus X-1. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2208.11476v1-abstract-full').style.display = 'none'; document.getElementById('2208.11476v1-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 August, 2022; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> August 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">11 pages, 15 figures, Accepted for publication in MNRAS 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/2208.04067">arXiv:2208.04067</a> <span> [<a href="https://arxiv.org/pdf/2208.04067">pdf</a>, <a href="https://arxiv.org/ps/2208.04067">ps</a>, <a href="https://arxiv.org/format/2208.04067">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="High Energy Astrophysical Phenomena">astro-ph.HE</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Astrophysics of Galaxies">astro-ph.GA</span> </div> <div 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/ac887e">10.3847/1538-4357/ac887e <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> The origin of the vanishing soft X-ray excess in the changing-look Active Galactic Nucleus Mrk 590 </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Ghosh%2C+R">Ritesh Ghosh</a>, <a href="/search/astro-ph?searchtype=author&query=Laha%2C+S">Sibasish Laha</a>, <a href="/search/astro-ph?searchtype=author&query=Deshmukh%2C+K">Kunal Deshmukh</a>, <a href="/search/astro-ph?searchtype=author&query=Bhalerao%2C+V">Varun Bhalerao</a>, <a href="/search/astro-ph?searchtype=author&query=Dewangan%2C+G+C">Gulab C. Dewangan</a>, <a href="/search/astro-ph?searchtype=author&query=Chatterjee%2C+R">Ritaban Chatterjee</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="2208.04067v2-abstract-short" style="display: inline;"> We have studied the nature and origin of the soft X-ray excess detected in the interesting changing-look AGN (CLAGN) Mrk~590 using two decades of multi-wavelength observations from \xmm{}, \suzaku{}, \swift{} and \nustar{}. In the light of vanishing soft excess in this CLAGN, we test two models, "the warm Comptonization" and "the ionized disk reflection" using extensive UV/X-ray spectral analysis.… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2208.04067v2-abstract-full').style.display = 'inline'; document.getElementById('2208.04067v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2208.04067v2-abstract-full" style="display: none;"> We have studied the nature and origin of the soft X-ray excess detected in the interesting changing-look AGN (CLAGN) Mrk~590 using two decades of multi-wavelength observations from \xmm{}, \suzaku{}, \swift{} and \nustar{}. In the light of vanishing soft excess in this CLAGN, we test two models, "the warm Comptonization" and "the ionized disk reflection" using extensive UV/X-ray spectral analysis. Our main findings are: (1) the soft X-ray excess emission, last observed in 2004, vanished in 2011, and never reappeared in any of the later observations, (2) we detected a significant variability ($\sim300\%$) in the observed optical-UV and power-law flux between observations with the lowest state ($L_{\rm bol} = 4.4\times 10^{43}\, erg\, s^{-1}$, in 2016) and the highest state ($L_{\rm bol} = 1.2\times 10^{44}\, erg\, s^{-1}$, in 2018), (3) the UV and power-law fluxes follow same temporal pattern, (4) the photon index showed a significant variation ($螕=1.88^{+0.02}_{-0.08}$ and $螕=1.58^{+0.02}_{-0.03}$ in 2002 and 2021 respectively) between observations, (5) no Compton hump was detected in the source spectra but a narrow Fe$K_伪$ line is present in all observations, (6) we detected a high-energy cut-off in power-law continuum ($92^{+55}_{-25} \rm keV$ and $60^{+10}_{-08} \rm keV$) with the latest \nustar{} observations, (7) the warm Comptonization model needs an additional diskbb component to describe the source UV bump, (8) there is no correlation between the Eddington rate and the soft excess as found in other changing-look AGNs. We conclude that given the spectral variability in UV/X-rays, the ionized disk reflection or the warm Comptonization models may not be adequate to describe the vanishing soft excess feature observed in Mrk~590. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2208.04067v2-abstract-full').style.display = 'none'; document.getElementById('2208.04067v2-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 29 September, 2022; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 8 August, 2022; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> August 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">Resubmitted to ApJ following minor comments from the referee</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2207.12758">arXiv:2207.12758</a> <span> [<a href="https://arxiv.org/pdf/2207.12758">pdf</a>, <a href="https://arxiv.org/format/2207.12758">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="High Energy Astrophysical Phenomena">astro-ph.HE</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Instrumentation and Methods for Astrophysics">astro-ph.IM</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1007/s12036-022-09886-9">10.1007/s12036-022-09886-9 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Pulsars in AstroSat-CZTI: Detection in sub-MeV bands and Estimation of Spectral Index from Hardness Ratios </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Anusree%2C+K+G">K. G. Anusree</a>, <a href="/search/astro-ph?searchtype=author&query=Bhattacharya%2C+D">Dipankar Bhattacharya</a>, <a href="/search/astro-ph?searchtype=author&query=Bhalerao%2C+V">Varun Bhalerao</a>, <a href="/search/astro-ph?searchtype=author&query=Anumarlapudi%2C+A">Akash Anumarlapudi</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2207.12758v2-abstract-short" style="display: inline;"> The Cadmium Zinc Telluride Imager (CZTI) onboard AstroSat, an open detector above $\sim$100 keV, is a promising tool for the investigation of hard X-ray characteristics of $纬$-ray pulsars. A custom algorithm has been developed to detect pulsars from long integration ($\sim$years) of archival data, as reported by us earlier. Here we extend this method to include in the analysis an additional… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2207.12758v2-abstract-full').style.display = 'inline'; document.getElementById('2207.12758v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2207.12758v2-abstract-full" style="display: none;"> The Cadmium Zinc Telluride Imager (CZTI) onboard AstroSat, an open detector above $\sim$100 keV, is a promising tool for the investigation of hard X-ray characteristics of $纬$-ray pulsars. A custom algorithm has been developed to detect pulsars from long integration ($\sim$years) of archival data, as reported by us earlier. Here we extend this method to include in the analysis an additional $\sim$20% of the CZTI pixels that were earlier ignored due to their lower gain values. Recent efforts have provided better and more secure calibration of these pixels, demonstrating their higher thresholds and extended energy range up to $\sim$1 MeV. Here we use the additional information provided by these pixels, enabling the construction of pulse profiles over a larger energy range. We compare the profiles of the Crab pulsar at different sub-bands and show that the behaviour is consistent with the extended energy coverage. As detailed spectroscopy over this full band remains difficult due to the limited count rate, we construct hardness ratios which, together with AstroSat Mass Model simulations, are able to constrain the power-law index of the radiation spectrum. We present our results for the phase-resolved spectrum of PSR J0534+2200 and for the total pulsed emission of PSR J1513-5908. The recovered photon indices are found to be accurate to within $\sim 20$%. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2207.12758v2-abstract-full').style.display = 'none'; document.getElementById('2207.12758v2-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, 2022; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 26 July, 2022; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> July 2022. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">Accepted for publication in the Journal of Astrophysics and Astronomy, 11 pages, 5 figures, 7 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/2207.09605">arXiv:2207.09605</a> <span> [<a href="https://arxiv.org/pdf/2207.09605">pdf</a>, <a href="https://arxiv.org/format/2207.09605">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="High Energy Astrophysical Phenomena">astro-ph.HE</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Instrumentation and Methods for Astrophysics">astro-ph.IM</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="High Energy Physics - Phenomenology">hep-ph</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.3847/1538-4357/ac82ef">10.3847/1538-4357/ac82ef <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Hard X-ray polarization catalog for a 5-year sample of Gamma-Ray Bursts using AstroSat CZT-Imager </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Chattopadhyay%2C+T">Tanmoy Chattopadhyay</a>, <a href="/search/astro-ph?searchtype=author&query=Gupta%2C+S">Soumya Gupta</a>, <a href="/search/astro-ph?searchtype=author&query=Iyyani%2C+S">Shabnam Iyyani</a>, <a href="/search/astro-ph?searchtype=author&query=Saraogi%2C+D">Divita Saraogi</a>, <a href="/search/astro-ph?searchtype=author&query=Sharma%2C+V">Vidushi Sharma</a>, <a href="/search/astro-ph?searchtype=author&query=Tsvetkova%2C+A">Anastasia Tsvetkova</a>, <a href="/search/astro-ph?searchtype=author&query=Ratheesh%2C+A">Ajay Ratheesh</a>, <a href="/search/astro-ph?searchtype=author&query=Gupta%2C+R">Rahul Gupta</a>, <a href="/search/astro-ph?searchtype=author&query=Mithun%2C+N+P+S">N. P. S. Mithun</a>, <a href="/search/astro-ph?searchtype=author&query=Vaishnava%2C+C+S">C. S. Vaishnava</a>, <a href="/search/astro-ph?searchtype=author&query=Prasad%2C+V">Vipul Prasad</a>, <a href="/search/astro-ph?searchtype=author&query=Aarthy%2C+E">E. Aarthy</a>, <a href="/search/astro-ph?searchtype=author&query=Kumar%2C+A">Abhay Kumar</a>, <a href="/search/astro-ph?searchtype=author&query=Rao%2C+A+R">A. R. Rao</a>, <a href="/search/astro-ph?searchtype=author&query=Vadawale%2C+S">Santosh Vadawale</a>, <a href="/search/astro-ph?searchtype=author&query=Bhalerao%2C+V">Varun Bhalerao</a>, <a href="/search/astro-ph?searchtype=author&query=Bhattacharya%2C+D">Dipankar Bhattacharya</a>, <a href="/search/astro-ph?searchtype=author&query=Vibhute%2C+A">Ajay Vibhute</a>, <a href="/search/astro-ph?searchtype=author&query=Frederiks%2C+D">Dmitry Frederiks</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2207.09605v1-abstract-short" style="display: inline;"> Cadmium Zinc Telluride Imager (CZTI) aboard AstroSat has been regularly detecting Gamma-Ray Bursts (GRBs) since its launch in 2015. Its sensitivity to polarization measurements at energies above 100 keV allows CZTI to attempt spectro-polarimetric studies of GRBs. Here, we present the first catalog of GRB polarization measurements made by CZTI during its first five years of operation. This presents… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2207.09605v1-abstract-full').style.display = 'inline'; document.getElementById('2207.09605v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2207.09605v1-abstract-full" style="display: none;"> Cadmium Zinc Telluride Imager (CZTI) aboard AstroSat has been regularly detecting Gamma-Ray Bursts (GRBs) since its launch in 2015. Its sensitivity to polarization measurements at energies above 100 keV allows CZTI to attempt spectro-polarimetric studies of GRBs. Here, we present the first catalog of GRB polarization measurements made by CZTI during its first five years of operation. This presents the time integrated polarization measurements of the prompt emission of 20 GRBs in the energy range 100-600 keV. The sample includes the bright GRBs which were detected within an angle range of 0-60 degree and 120-180 degree where the instrument has useful polarization sensitivity and is less prone to systematics. We implement a few new modifications in the analysis to enhance polarimetric sensitivity of the instrument. Majority of the GRBs in the sample are found to possess less / null polarization across the total bursts' duration in contrast to a small fraction of five GRBs exhibiting high polarization. The low polarization across the bursts can be speculated to be either due to the burst being intrinsically weakly polarized or due to varying polarization angle within the burst even when it is highly polarized. In comparison to POLAR measurements, CZTI has detected a larger number of cases with high polarization. This may be a consequence of the higher energy window of CZTI observations which results in the sampling of smaller duration of burst emissions in contrast to POLAR, thereby, probing emissions of less temporal variations of polarization properties. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2207.09605v1-abstract-full').style.display = 'none'; document.getElementById('2207.09605v1-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 July, 2022; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> July 2022. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">Accepted for publication in ApJ</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> The Astrophysical Journal, volume - 936, number -1, pages - 12, year - 2022 </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2206.13535">arXiv:2206.13535</a> <span> [<a href="https://arxiv.org/pdf/2206.13535">pdf</a>, <a href="https://arxiv.org/format/2206.13535">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/ac7bea">10.3847/1538-3881/ac7bea <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> India's first robotic eye for time domain astrophysics: the GROWTH-India telescope </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Kumar%2C+H">Harsh Kumar</a>, <a href="/search/astro-ph?searchtype=author&query=Bhalerao%2C+V">Varun Bhalerao</a>, <a href="/search/astro-ph?searchtype=author&query=Anupama%2C+G+C">G. C. Anupama</a>, <a href="/search/astro-ph?searchtype=author&query=Barway%2C+S">Sudhanshu Barway</a>, <a href="/search/astro-ph?searchtype=author&query=Basu%2C+J">Judhajeet Basu</a>, <a href="/search/astro-ph?searchtype=author&query=Deshmukh%2C+K">Kunal Deshmukh</a>, <a href="/search/astro-ph?searchtype=author&query=De%2C+K">Kishalay De</a>, <a href="/search/astro-ph?searchtype=author&query=Dutta%2C+A">Anirban Dutta</a>, <a href="/search/astro-ph?searchtype=author&query=Fremling%2C+C">Christoffer Fremling</a>, <a href="/search/astro-ph?searchtype=author&query=Iyer%2C+H">Hrishikesh Iyer</a>, <a href="/search/astro-ph?searchtype=author&query=Jassani%2C+A">Adeem Jassani</a>, <a href="/search/astro-ph?searchtype=author&query=Joharle%2C+S">Simran Joharle</a>, <a href="/search/astro-ph?searchtype=author&query=Karambelkar%2C+V">Viraj Karambelkar</a>, <a href="/search/astro-ph?searchtype=author&query=Khandagale%2C+M">Maitreya Khandagale</a>, <a href="/search/astro-ph?searchtype=author&query=Krishna%2C+K+A">K Adithya Krishna</a>, <a href="/search/astro-ph?searchtype=author&query=Kulkarni%2C+S">Sumeet Kulkarni</a>, <a href="/search/astro-ph?searchtype=author&query=Mate%2C+S">Sujay Mate</a>, <a href="/search/astro-ph?searchtype=author&query=Patil%2C+A">Atharva Patil</a>, <a href="/search/astro-ph?searchtype=author&query=Phanindra%2C+D">DVS Phanindra</a>, <a href="/search/astro-ph?searchtype=author&query=Samantaray%2C+S">Subham Samantaray</a>, <a href="/search/astro-ph?searchtype=author&query=Sharma%2C+K">Kritti Sharma</a>, <a href="/search/astro-ph?searchtype=author&query=Sharma%2C+Y">Yashvi Sharma</a>, <a href="/search/astro-ph?searchtype=author&query=Shenoy%2C+V">Vedant Shenoy</a>, <a href="/search/astro-ph?searchtype=author&query=Singh%2C+A">Avinash Singh</a>, <a href="/search/astro-ph?searchtype=author&query=Srivastava%2C+S">Shubham Srivastava</a> , et al. (13 additional authors not shown) </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2206.13535v1-abstract-short" style="display: inline;"> We present the design and performance of the GROWTH-India telescope, a 0.7 m robotic telescope dedicated to time-domain astronomy. The telescope is equipped with a 4k back-illuminated camera giving a 0.82-degree field of view and sensitivity of m_g ~20.5 in 5-min exposures. Custom software handles observatory operations: attaining high on-sky observing efficiencies (>~ 80%) and allowing rapid resp… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2206.13535v1-abstract-full').style.display = 'inline'; document.getElementById('2206.13535v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2206.13535v1-abstract-full" style="display: none;"> We present the design and performance of the GROWTH-India telescope, a 0.7 m robotic telescope dedicated to time-domain astronomy. The telescope is equipped with a 4k back-illuminated camera giving a 0.82-degree field of view and sensitivity of m_g ~20.5 in 5-min exposures. Custom software handles observatory operations: attaining high on-sky observing efficiencies (>~ 80%) and allowing rapid response to targets of opportunity. The data processing pipelines are capable of performing PSF photometry as well as image subtraction for transient searches. We also present an overview of the GROWTH-India telescope's contributions to the studies of Gamma-ray Bursts, the electromagnetic counterparts to gravitational wave sources, supernovae, novae and solar system objects. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2206.13535v1-abstract-full').style.display = 'none'; document.getElementById('2206.13535v1-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 June, 2022; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> June 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">17 pages, 8 figures, Accepted for publication in 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/2204.07587">arXiv:2204.07587</a> <span> [<a href="https://arxiv.org/pdf/2204.07587">pdf</a>, <a href="https://arxiv.org/format/2204.07587">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/10.1093/mnras/stac1061">10.1093/mnras/stac1061 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> The long-active afterglow of GRB 210204A: Detection of the most delayed flares in a Gamma-Ray Burst </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Kumar%2C+H">Harsh Kumar</a>, <a href="/search/astro-ph?searchtype=author&query=Gupta%2C+R">Rahul Gupta</a>, <a href="/search/astro-ph?searchtype=author&query=Saraogi%2C+D">Divita Saraogi</a>, <a href="/search/astro-ph?searchtype=author&query=Ahumada%2C+T">Tom谩s Ahumada</a>, <a href="/search/astro-ph?searchtype=author&query=Andreoni%2C+I">Igor Andreoni</a>, <a href="/search/astro-ph?searchtype=author&query=Anupama%2C+G+C">G. C. Anupama</a>, <a href="/search/astro-ph?searchtype=author&query=Aryan%2C+A">Amar Aryan</a>, <a href="/search/astro-ph?searchtype=author&query=Barway%2C+S">Sudhanshu Barway</a>, <a href="/search/astro-ph?searchtype=author&query=Bhalerao%2C+V">Varun Bhalerao</a>, <a href="/search/astro-ph?searchtype=author&query=Chandra%2C+P">Poonam Chandra</a>, <a href="/search/astro-ph?searchtype=author&query=Coughlin%2C+M+W">Michael W. Coughlin</a>, <a href="/search/astro-ph?searchtype=author&query=Dimple"> Dimple</a>, <a href="/search/astro-ph?searchtype=author&query=Dutta%2C+A">Anirban Dutta</a>, <a href="/search/astro-ph?searchtype=author&query=Ghosh%2C+A">Ankur Ghosh</a>, <a href="/search/astro-ph?searchtype=author&query=Ho%2C+A+Y+Q">Anna Y. Q. Ho</a>, <a href="/search/astro-ph?searchtype=author&query=Kool%2C+E+C">E. C. Kool</a>, <a href="/search/astro-ph?searchtype=author&query=Kumar%2C+A">Amit Kumar</a>, <a href="/search/astro-ph?searchtype=author&query=Medford%2C+M+S">Michael S. Medford</a>, <a href="/search/astro-ph?searchtype=author&query=Misra%2C+K">Kuntal Misra</a>, <a href="/search/astro-ph?searchtype=author&query=Pandey%2C+S+B">Shashi B. Pandey</a>, <a href="/search/astro-ph?searchtype=author&query=Perley%2C+D+A">Daniel A. Perley</a>, <a href="/search/astro-ph?searchtype=author&query=Riddle%2C+R">Reed Riddle</a>, <a href="/search/astro-ph?searchtype=author&query=Ror%2C+A+K">Amit Kumar Ror</a>, <a href="/search/astro-ph?searchtype=author&query=Setiadi%2C+J+M">Jason M. Setiadi</a>, <a href="/search/astro-ph?searchtype=author&query=Yao%2C+Y">Yuhan Yao</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2204.07587v1-abstract-short" style="display: inline;"> We present results from extensive broadband follow-up of GRB 210204A over the period of thirty days. We detect optical flares in the afterglow at 7.6 x 10^5 s and 1.1 x 10^6 s after the burst: the most delayed flaring ever detected in a GRB afterglow. At the source redshift of 0.876, the rest-frame delay is 5.8 x 10^5 s (6.71 d). We investigate possible causes for this flaring and conclude that th… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2204.07587v1-abstract-full').style.display = 'inline'; document.getElementById('2204.07587v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2204.07587v1-abstract-full" style="display: none;"> We present results from extensive broadband follow-up of GRB 210204A over the period of thirty days. We detect optical flares in the afterglow at 7.6 x 10^5 s and 1.1 x 10^6 s after the burst: the most delayed flaring ever detected in a GRB afterglow. At the source redshift of 0.876, the rest-frame delay is 5.8 x 10^5 s (6.71 d). We investigate possible causes for this flaring and conclude that the most likely cause is a refreshed shock in the jet. The prompt emission of the GRB is within the range of typical long bursts: it shows three disjoint emission episodes, which all follow the typical GRB correlations. This suggests that GRB 210204A might not have any special properties that caused late-time flaring, and the lack of such detections for other afterglows might be resulting from the paucity of late-time observations. Systematic late-time follow-up of a larger sample of GRBs can shed more light on such afterglow behaviour. Further analysis of the GRB 210204A shows that the late time bump in the light curve is highly unlikely due to underlying SNe at redshift (z) = 0.876 and is more likely due to the late time flaring activity. The cause of this variability is not clearly quantifiable due to the lack of multi-band data at late time constraints by the bad weather conditions. The flare of GRB 210204A is the latest flare detected to date. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2204.07587v1-abstract-full').style.display = 'none'; document.getElementById('2204.07587v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 15 April, 2022; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> April 2022. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">18 pages, 12 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/2204.05648">arXiv:2204.05648</a> <span> [<a href="https://arxiv.org/pdf/2204.05648">pdf</a>, <a href="https://arxiv.org/format/2204.05648">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="High Energy Astrophysical Phenomena">astro-ph.HE</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="General Relativity and Quantum Cosmology">gr-qc</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1007/s12036-022-09841-8">10.1007/s12036-022-09841-8 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Gravitational Waves and Electromagnetic Transients </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Singhal%2C+A">Akshat Singhal</a>, <a href="/search/astro-ph?searchtype=author&query=Palit%2C+S">Sourav Palit</a>, <a href="/search/astro-ph?searchtype=author&query=Bala%2C+S">Suman Bala</a>, <a href="/search/astro-ph?searchtype=author&query=Waratkar%2C+G">Gaurav Waratkar</a>, <a href="/search/astro-ph?searchtype=author&query=Kumar%2C+H">Harsh Kumar</a>, <a href="/search/astro-ph?searchtype=author&query=Bhalerao%2C+V">Varun Bhalerao</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2204.05648v2-abstract-short" style="display: inline;"> The advanced gravitational wave (GW) detector network has started {routine detection of } signals from merging compact binaries. Data indicate that in a fair fraction of these sources, at least one component was a neutron star, bringing with it the possibility of electromagnetic (EM) radiation. So far, a confirmed link between EM and GW radiation has been established for only one source, GW170817.… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2204.05648v2-abstract-full').style.display = 'inline'; document.getElementById('2204.05648v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2204.05648v2-abstract-full" style="display: none;"> The advanced gravitational wave (GW) detector network has started {routine detection of } signals from merging compact binaries. Data indicate that in a fair fraction of these sources, at least one component was a neutron star, bringing with it the possibility of electromagnetic (EM) radiation. So far, a confirmed link between EM and GW radiation has been established for only one source, GW170817. Joint analysis of broadband multiwavelength data and the GW signal have yielded rich information spanning fields as varied as jet physics, cosmology, and nucleosynthesis. Here, we discuss the importance of such joint observations, as well as current and near-future efforts to discover and study more EM counterparts to GW sources. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2204.05648v2-abstract-full').style.display = 'none'; document.getElementById('2204.05648v2-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 April, 2022; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 12 April, 2022; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> April 2022. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">14 pages, 3 figures, 3 tables, review paper in Journal of Astrophysics and Astronomy</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Journal of Astrophysics and Astronomy, Volume 43, Issue 2, article id.53, December 2022 </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2203.11787">arXiv:2203.11787</a> <span> [<a href="https://arxiv.org/pdf/2203.11787">pdf</a>, <a href="https://arxiv.org/format/2203.11787">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/ac6c29">10.3847/1538-4357/ac6c29 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> In search of short gamma-ray burst optical counterpart with the Zwicky Transient Facility </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Ahumada%2C+T">Tom谩s Ahumada</a>, <a href="/search/astro-ph?searchtype=author&query=Anand%2C+S">Shreya Anand</a>, <a href="/search/astro-ph?searchtype=author&query=Coughlin%2C+M+W">Michael W. Coughlin</a>, <a href="/search/astro-ph?searchtype=author&query=Andreoni%2C+I">Igor Andreoni</a>, <a href="/search/astro-ph?searchtype=author&query=Kool%2C+E+C">Erik C. Kool</a>, <a href="/search/astro-ph?searchtype=author&query=Kumar%2C+H">Harsh Kumar</a>, <a href="/search/astro-ph?searchtype=author&query=Reusch%2C+S">Simeon Reusch</a>, <a href="/search/astro-ph?searchtype=author&query=Sagu%C3%A9s-Carracedo%2C+A">Ana Sagu茅s-Carracedo</a>, <a href="/search/astro-ph?searchtype=author&query=Stein%2C+R">Robert Stein</a>, <a href="/search/astro-ph?searchtype=author&query=Cenko%2C+S+B">S. Bradley Cenko</a>, <a href="/search/astro-ph?searchtype=author&query=Kasliwal%2C+M+M">Mansi M. Kasliwal</a>, <a href="/search/astro-ph?searchtype=author&query=Singer%2C+L+P">Leo P. Singer</a>, <a href="/search/astro-ph?searchtype=author&query=Dunwoody%2C+R">Rachel Dunwoody</a>, <a href="/search/astro-ph?searchtype=author&query=Mangan%2C+J">Joseph Mangan</a>, <a href="/search/astro-ph?searchtype=author&query=Bhalerao%2C+V">Varun Bhalerao</a>, <a href="/search/astro-ph?searchtype=author&query=Bulla%2C+M">Mattia Bulla</a>, <a href="/search/astro-ph?searchtype=author&query=Burns%2C+E">Eric Burns</a>, <a href="/search/astro-ph?searchtype=author&query=Graham%2C+M+J">Matthew J. Graham</a>, <a href="/search/astro-ph?searchtype=author&query=Kaplan%2C+D+L">David L. Kaplan</a>, <a href="/search/astro-ph?searchtype=author&query=Perley%2C+D">Daniel Perley</a>, <a href="/search/astro-ph?searchtype=author&query=Almualla%2C+M">Mouza Almualla</a>, <a href="/search/astro-ph?searchtype=author&query=Bloom%2C+J+S">Joshua S. Bloom</a>, <a href="/search/astro-ph?searchtype=author&query=Cunningham%2C+V">Virginia Cunningham</a>, <a href="/search/astro-ph?searchtype=author&query=De%2C+K">Kishalay De</a>, <a href="/search/astro-ph?searchtype=author&query=Gatkine%2C+P">Pradip Gatkine</a> , et al. (24 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="2203.11787v1-abstract-short" style="display: inline;"> The Fermi Gamma-ray Burst Monitor (GBM) triggers on-board in response to $\sim$ 40 short gamma-ray bursts (SGRBs) per year; however, their large localization regions have made the search for optical counterparts a challenging endeavour. We have developed and executed an extensive program with the wide field of view of the Zwicky Transient Facility (ZTF) camera, mounted on the Palomar 48 inch Oschi… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2203.11787v1-abstract-full').style.display = 'inline'; document.getElementById('2203.11787v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2203.11787v1-abstract-full" style="display: none;"> The Fermi Gamma-ray Burst Monitor (GBM) triggers on-board in response to $\sim$ 40 short gamma-ray bursts (SGRBs) per year; however, their large localization regions have made the search for optical counterparts a challenging endeavour. We have developed and executed an extensive program with the wide field of view of the Zwicky Transient Facility (ZTF) camera, mounted on the Palomar 48 inch Oschin telescope (P48), to perform target-of-opportunity (ToO) observations on 10 Fermi-GBM SGRBs during 2018 and 2020-2021. Bridging the large sky areas with small field of view optical telescopes in order to track the evolution of potential candidates, we look for the elusive SGRB afterglows and kilonovae (KNe) associated with these high-energy events. No counterpart has yet been found, even though more than 10 ground based telescopes, part of the Global Relay of Observatories Watching Transients Happen (GROWTH) network, have taken part in these efforts. The candidate selection procedure and the follow-up strategy have shown that ZTF is an efficient instrument for searching for poorly localized SGRBs, retrieving a reasonable number of candidates to follow-up and showing promising capabilities as the community approaches the multi-messenger era. Based on the median limiting magnitude of ZTF, our searches would have been able to retrieve a GW170817-like event up to $\sim$ 200 Mpc and SGRB afterglows to z = 0.16 or 0.4, depending on the assumed underlying energy model. Future ToOs will expand the horizon to z = 0.2 and 0.7 respectively. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2203.11787v1-abstract-full').style.display = 'none'; document.getElementById('2203.11787v1-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 March, 2022; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> March 2022. </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2203.07866">arXiv:2203.07866</a> <span> [<a href="https://arxiv.org/pdf/2203.07866">pdf</a>, <a href="https://arxiv.org/ps/2203.07866">ps</a>, <a href="https://arxiv.org/format/2203.07866">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"> Demonstrating the Concept of Parallax with James Webb Space Telescope </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Ngeow%2C+C">Chow-Choong Ngeow</a>, <a href="/search/astro-ph?searchtype=author&query=Kumar%2C+H">Harsh Kumar</a>, <a href="/search/astro-ph?searchtype=author&query=Bhalerao%2C+V">Varun Bhalerao</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="2203.07866v1-abstract-short" style="display: inline;"> We measured the parallax of the James Webb Space Telescope based on near simultaneous observations using the Lulin One-meter Telescope and the GROWTH India Telescope, separated at a distance of ~4214 km. This serves a great demonstration for the concept of parallax commonly taught in introductory astronomy courses. </span> <span class="abstract-full has-text-grey-dark mathjax" id="2203.07866v1-abstract-full" style="display: none;"> We measured the parallax of the James Webb Space Telescope based on near simultaneous observations using the Lulin One-meter Telescope and the GROWTH India Telescope, separated at a distance of ~4214 km. This serves a great demonstration for the concept of parallax commonly taught in introductory astronomy courses. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2203.07866v1-abstract-full').style.display = 'none'; document.getElementById('2203.07866v1-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, 2022; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> March 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">2 pages and 1 figure, RNAAS 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/2201.01167">arXiv:2201.01167</a> <span> [<a href="https://arxiv.org/pdf/2201.01167">pdf</a>, <a href="https://arxiv.org/format/2201.01167">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/10.1093/mnras/stac015">10.1093/mnras/stac015 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Probing into emission mechanisms of GRB 190530A using time-resolved spectra and polarization studies: Synchrotron Origin? </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Gupta%2C+R">Rahul Gupta</a>, <a href="/search/astro-ph?searchtype=author&query=Gupta%2C+S">S. Gupta</a>, <a href="/search/astro-ph?searchtype=author&query=Chattopadhyay%2C+T">T. Chattopadhyay</a>, <a href="/search/astro-ph?searchtype=author&query=Lipunov%2C+V">V. Lipunov</a>, <a href="/search/astro-ph?searchtype=author&query=Castro-Tirado%2C+A+J">A. J. Castro-Tirado</a>, <a href="/search/astro-ph?searchtype=author&query=Bhattacharya%2C+D">D. Bhattacharya</a>, <a href="/search/astro-ph?searchtype=author&query=Pandey%2C+S+B">S. B. Pandey</a>, <a href="/search/astro-ph?searchtype=author&query=Oates%2C+S+R">S. R. Oates</a>, <a href="/search/astro-ph?searchtype=author&query=Kumar%2C+A">Amit Kumar</a>, <a href="/search/astro-ph?searchtype=author&query=Hu%2C+Y+-">Y. -D. Hu</a>, <a href="/search/astro-ph?searchtype=author&query=Valeev%2C+A+F">A. F. Valeev</a>, <a href="/search/astro-ph?searchtype=author&query=Minaev%2C+P+Y">P. Yu. Minaev</a>, <a href="/search/astro-ph?searchtype=author&query=Kumar%2C+H">H. Kumar</a>, <a href="/search/astro-ph?searchtype=author&query=Vinko%2C+J">J. Vinko</a>, <a href="/search/astro-ph?searchtype=author&query=Dimple"> Dimple</a>, <a href="/search/astro-ph?searchtype=author&query=Sharma%2C+V">V. Sharma</a>, <a href="/search/astro-ph?searchtype=author&query=Aryan%2C+A">A. Aryan</a>, <a href="/search/astro-ph?searchtype=author&query=Castell%C3%B3n%2C+A">A. Castell贸n</a>, <a href="/search/astro-ph?searchtype=author&query=Gabovich%2C+A">A. Gabovich</a>, <a href="/search/astro-ph?searchtype=author&query=Moskvitin%2C+A">A. Moskvitin</a>, <a href="/search/astro-ph?searchtype=author&query=Ordasi%2C+A">A. Ordasi</a>, <a href="/search/astro-ph?searchtype=author&query=P%C3%A1l%2C+A">A. P谩l</a>, <a href="/search/astro-ph?searchtype=author&query=Pozanenko%2C+A">A. Pozanenko</a>, <a href="/search/astro-ph?searchtype=author&query=Zhang%2C+B+-">B. -B. Zhang</a>, <a href="/search/astro-ph?searchtype=author&query=Kumar%2C+B">B. Kumar</a> , et al. (25 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="2201.01167v1-abstract-short" style="display: inline;"> Multi-pulsed GRB 190530A, detected by the GBM and LAT onboard \fermi, is the sixth most fluent GBM burst detected so far. This paper presents the timing, spectral, and polarimetric analysis of the prompt emission observed using \AstroSat and \fermi to provide insight into the prompt emission radiation mechanisms. The time-integrated spectrum shows conclusive proof of two breaks due to peak energy… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2201.01167v1-abstract-full').style.display = 'inline'; document.getElementById('2201.01167v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2201.01167v1-abstract-full" style="display: none;"> Multi-pulsed GRB 190530A, detected by the GBM and LAT onboard \fermi, is the sixth most fluent GBM burst detected so far. This paper presents the timing, spectral, and polarimetric analysis of the prompt emission observed using \AstroSat and \fermi to provide insight into the prompt emission radiation mechanisms. The time-integrated spectrum shows conclusive proof of two breaks due to peak energy and a second lower energy break. Time-integrated (55.43 $\pm$ 21.30 \%) as well as time-resolved polarization measurements, made by the Cadmium Zinc Telluride Imager (CZTI) onboard \AstroSat, show a hint of high degree of polarization. The presence of a hint of high degree of polarization and the values of low energy spectral index ($伪_{\rm pt}$) do not run over the synchrotron limit for the first two pulses, supporting the synchrotron origin in an ordered magnetic field. However, during the third pulse, $伪_{\rm pt}$ exceeds the synchrotron line of death in few bins, and a thermal signature along with the synchrotron component in the time-resolved spectra is observed. Furthermore, we also report the earliest optical observations constraining afterglow polarization using the MASTER (P $<$ 1.3 \%) and the redshift measurement ($z$= 0.9386) obtained with the 10.4m GTC telescopes. The broadband afterglow can be described with a forward shock model for an ISM-like medium with a wide jet opening angle. We determine a circumburst density of $n_{0} \sim$ 7.41, kinetic energy $E_{\rm K} \sim$ 7.24 $\times 10^{54}$ erg, and radiated $纬$-ray energy $E_{\rm 纬, iso} \sim$ 6.05 $\times 10^{54}$ erg, respectively. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2201.01167v1-abstract-full').style.display = 'none'; document.getElementById('2201.01167v1-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 January, 2022; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> January 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">28 pages, 17 figures, accepted for publication in MNRAS</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2111.01226">arXiv:2111.01226</a> <span> [<a href="https://arxiv.org/pdf/2111.01226">pdf</a>, <a href="https://arxiv.org/format/2111.01226">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/ac366f">10.3847/1538-4357/ac366f <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> SN 2020sck: deflagration in a carbon-oxygen white dwarf </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Dutta%2C+A">Anirban Dutta</a>, <a href="/search/astro-ph?searchtype=author&query=Sahu%2C+D+K">D. K. Sahu</a>, <a href="/search/astro-ph?searchtype=author&query=Anupama%2C+G+C">G. C. Anupama</a>, <a href="/search/astro-ph?searchtype=author&query=Joharle%2C+S">Simran Joharle</a>, <a href="/search/astro-ph?searchtype=author&query=Kumar%2C+B">Brajesh Kumar</a>, <a href="/search/astro-ph?searchtype=author&query=Nayana%2C+A+J">A. J. Nayana</a>, <a href="/search/astro-ph?searchtype=author&query=Singh%2C+A">Avinash Singh</a>, <a href="/search/astro-ph?searchtype=author&query=Kumar%2C+H">Harsh Kumar</a>, <a href="/search/astro-ph?searchtype=author&query=Bhalerao%2C+V">Varun Bhalerao</a>, <a href="/search/astro-ph?searchtype=author&query=Barway%2C+S">Sudhansu Barway</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="2111.01226v1-abstract-short" style="display: inline;"> We present optical UBVRI photometry and low-to-medium resolution spectroscopic observations of type Iax SN 2020sck spanning -5.5 d to +67 d from maximum light in the B-band. From the photometric analysis we find $螖m_{\rm{B}}$(15) = 2.03$\pm$0.05 mag and $M_{\rm{B}}$=-17.81$\pm$0.22 mag. Radiation diffusion model fit to the quasi-bolometric light curve indicates 0.13$\pm$0.02 $M_{\odot}$ of… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2111.01226v1-abstract-full').style.display = 'inline'; document.getElementById('2111.01226v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2111.01226v1-abstract-full" style="display: none;"> We present optical UBVRI photometry and low-to-medium resolution spectroscopic observations of type Iax SN 2020sck spanning -5.5 d to +67 d from maximum light in the B-band. From the photometric analysis we find $螖m_{\rm{B}}$(15) = 2.03$\pm$0.05 mag and $M_{\rm{B}}$=-17.81$\pm$0.22 mag. Radiation diffusion model fit to the quasi-bolometric light curve indicates 0.13$\pm$0.02 $M_{\odot}$ of $^{56}$Ni and 0.34 $M_{\rm \odot}$ of ejecta are synthesized in the explosion. Comparing the observed quasi-bolometric light curve with angle-averaged bolometric light curve of three-dimensional pure deflagration explosion of $M_{\rm{ch}}$ carbon-oxygen white dwarf, we find agreement with a model in which 0.16 $M_{\odot}$ of $^{56}$Ni and 0.37 $M_{\odot}$ of ejecta is formed. By comparing the +1.4 day spectrum of SN 2020sck with synthetic spectrum generated using SYN++, we find absorption features due to C II, C III and O I. These are unburned materials in the explosion and indicate a C-O white dwarf. One dimensional radiative transfer modeling of the spectra with TARDIS shows higher density in the ejecta near the photosphere and a steep decrease in the outer layers with an ejecta composition dominated mostly by C, O, Si, Fe, and Ni. The star formation rate of the host galaxy computed from the luminosity of the H$伪$ ($位$6563) line is 0.09 $M_{\odot}$ yr$^{-1}$ indicating a relatively young stellar environment. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2111.01226v1-abstract-full').style.display = 'none'; document.getElementById('2111.01226v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 1 November, 2021; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> November 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, 17 figures, 11 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/2108.06746">arXiv:2108.06746</a> <span> [<a href="https://arxiv.org/pdf/2108.06746">pdf</a>, <a href="https://arxiv.org/format/2108.06746">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Instrumentation and Methods for Astrophysics">astro-ph.IM</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1007/s12036-021-09762-y">10.1007/s12036-021-09762-y <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Imaging calibration of AstroSat Cadmium Zinc Telluride Imager (CZTI) </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Vibhute%2C+A">Ajay Vibhute</a>, <a href="/search/astro-ph?searchtype=author&query=Bhattacharya%2C+D">Dipankar Bhattacharya</a>, <a href="/search/astro-ph?searchtype=author&query=Mithun%2C+N+P+S">N. P. S. Mithun</a>, <a href="/search/astro-ph?searchtype=author&query=Bhalerao%2C+V">V. Bhalerao</a>, <a href="/search/astro-ph?searchtype=author&query=Rao%2C+A+R">A. R. Rao</a>, <a href="/search/astro-ph?searchtype=author&query=Vadawale%2C+S+V">S. V. Vadawale</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="2108.06746v1-abstract-short" style="display: inline;"> AstroSat is India's first space-based astronomical observatory, launched on September 28, 2015. One of the payloads aboard AstroSat is the Cadmium Zinc Telluride Imager (CZTI), operating at hard X-rays. CZTI employs a two-dimensional coded aperture mask for the purpose of imaging. In this paper, we discuss various image reconstruction algorithms adopted for the test and calibration of the imaging… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2108.06746v1-abstract-full').style.display = 'inline'; document.getElementById('2108.06746v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2108.06746v1-abstract-full" style="display: none;"> AstroSat is India's first space-based astronomical observatory, launched on September 28, 2015. One of the payloads aboard AstroSat is the Cadmium Zinc Telluride Imager (CZTI), operating at hard X-rays. CZTI employs a two-dimensional coded aperture mask for the purpose of imaging. In this paper, we discuss various image reconstruction algorithms adopted for the test and calibration of the imaging capability of CZTI and present results from CZTI on-ground as well as in-orbit image calibration. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2108.06746v1-abstract-full').style.display = 'none'; document.getElementById('2108.06746v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 15 August, 2021; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> August 2021. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">16 pages, 21 images, Payload Calibration, Accepted in JAA on AstroSat 5 years special issue</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2108.00029">arXiv:2108.00029</a> <span> [<a href="https://arxiv.org/pdf/2108.00029">pdf</a>, <a href="https://arxiv.org/format/2108.00029">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Instrumentation and Methods for Astrophysics">astro-ph.IM</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1093/mnras/stab2246">10.1093/mnras/stab2246 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Deep Co-Added Sky from Catalina Sky Survey Images </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Singhal%2C+A">Akshat Singhal</a>, <a href="/search/astro-ph?searchtype=author&query=Bhalerao%2C+V">Varun Bhalerao</a>, <a href="/search/astro-ph?searchtype=author&query=Mahabal%2C+A+A">Ashish A. Mahabal</a>, <a href="/search/astro-ph?searchtype=author&query=Vaghmare%2C+K">Kaustubh Vaghmare</a>, <a href="/search/astro-ph?searchtype=author&query=Jagade%2C+S">Santosh Jagade</a>, <a href="/search/astro-ph?searchtype=author&query=Kulkarni%2C+S">Sumeet Kulkarni</a>, <a href="/search/astro-ph?searchtype=author&query=Vibhute%2C+A">Ajay Vibhute</a>, <a href="/search/astro-ph?searchtype=author&query=Kembhavi%2C+A+K">Ajit K. Kembhavi</a>, <a href="/search/astro-ph?searchtype=author&query=Drake%2C+A+J">Andrew J. Drake</a>, <a href="/search/astro-ph?searchtype=author&query=Djorgovski%2C+S+G">S George Djorgovski</a>, <a href="/search/astro-ph?searchtype=author&query=Graham%2C+M+J">Matthew J. Graham</a>, <a href="/search/astro-ph?searchtype=author&query=Donalek%2C+C">Ciro Donalek</a>, <a href="/search/astro-ph?searchtype=author&query=Christensen%2C+E">Eric Christensen</a>, <a href="/search/astro-ph?searchtype=author&query=Larson%2C+S">Stephen Larson</a>, <a href="/search/astro-ph?searchtype=author&query=Beshore%2C+E+C">Edward C. Beshore</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="2108.00029v1-abstract-short" style="display: inline;"> A number of synoptic sky surveys are underway or being planned. Typically they are done with small telescopes and relatively short exposure times. A search for transient or variable sources involves comparison with deeper baseline images, ideally obtained through the same telescope and camera. With that in mind we have stacked images from the 0.68~m Schmidt telescope on Mt. Bigelow taken over ten… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2108.00029v1-abstract-full').style.display = 'inline'; document.getElementById('2108.00029v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2108.00029v1-abstract-full" style="display: none;"> A number of synoptic sky surveys are underway or being planned. Typically they are done with small telescopes and relatively short exposure times. A search for transient or variable sources involves comparison with deeper baseline images, ideally obtained through the same telescope and camera. With that in mind we have stacked images from the 0.68~m Schmidt telescope on Mt. Bigelow taken over ten years as part of the Catalina Sky Survey. In order to generate deep reference images for the Catalina Real-time Transient Survey, close to 0.8 million images over 8000 fields and covering over 27000~sq.~deg. have gone into the deep stack that goes up to 3 magnitudes deeper than individual images. CRTS system does not use a filter in imaging, hence there is no standard passband in which the optical magnitude is measured. We estimate depth by comparing these wide-band unfiltered co-added images with images in the $g$-band and find that the image depth ranges from 22.0--24.2 across the sky, with a 200-image stack attaining an equivalent AB magnitude sensitivity of 22.8. We compared various state-of-the-art software packages for co-adding astronomical images and have used SWarp for the stacking. We describe here the details of the process adopted. This methodology may be useful in other panoramic imaging applications, and to other surveys as well. The stacked images are available through a server at Inter-University Centre for Astronomy and Astrophysics (IUCAA). <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2108.00029v1-abstract-full').style.display = 'none'; document.getElementById('2108.00029v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 30 July, 2021; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> August 2021. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">16 pages, 15 figures</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2105.13145">arXiv:2105.13145</a> <span> [<a href="https://arxiv.org/pdf/2105.13145">pdf</a>, <a href="https://arxiv.org/format/2105.13145">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/10.1093/mnras/stab1573">10.1093/mnras/stab1573 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> GRB 140102A: Insight into Prompt Spectral Evolution and Early Optical Afterglow Emission </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Gupta%2C+R">Rahul Gupta</a>, <a href="/search/astro-ph?searchtype=author&query=Oates%2C+S+R">S. R. Oates</a>, <a href="/search/astro-ph?searchtype=author&query=Pandey%2C+S+B">S. B. Pandey</a>, <a href="/search/astro-ph?searchtype=author&query=Castro-Tirado%2C+A+J">A. J. Castro-Tirado</a>, <a href="/search/astro-ph?searchtype=author&query=Joshi%2C+J+C">Jagdish C. Joshi</a>, <a href="/search/astro-ph?searchtype=author&query=Hu%2C+Y+-">Y. -D. Hu</a>, <a href="/search/astro-ph?searchtype=author&query=Valeev%2C+A+F">A. F. Valeev</a>, <a href="/search/astro-ph?searchtype=author&query=Zhang%2C+B+B">B. B. Zhang</a>, <a href="/search/astro-ph?searchtype=author&query=Zhang%2C+Z">Z. Zhang</a>, <a href="/search/astro-ph?searchtype=author&query=Kumar%2C+A">Amit Kumar</a>, <a href="/search/astro-ph?searchtype=author&query=Aryan%2C+A">A. Aryan</a>, <a href="/search/astro-ph?searchtype=author&query=Lien%2C+A">A. Lien</a>, <a href="/search/astro-ph?searchtype=author&query=Kumar%2C+B">B. Kumar</a>, <a href="/search/astro-ph?searchtype=author&query=Cui%2C+C">Ch. Cui</a>, <a href="/search/astro-ph?searchtype=author&query=Wang%2C+C">Ch. Wang</a>, <a href="/search/astro-ph?searchtype=author&query=Dimple"> Dimple</a>, <a href="/search/astro-ph?searchtype=author&query=Bhattacharya%2C+D">D. Bhattacharya</a>, <a href="/search/astro-ph?searchtype=author&query=Sonbas%2C+E">E. Sonbas</a>, <a href="/search/astro-ph?searchtype=author&query=Bai%2C+J">J. Bai</a>, <a href="/search/astro-ph?searchtype=author&query=Tello%2C+J+C">J. C. Tello</a>, <a href="/search/astro-ph?searchtype=author&query=Gorosabel%2C+J">J. Gorosabel</a>, <a href="/search/astro-ph?searchtype=author&query=Cer%C3%B3n%2C+J+M+C">J. M. Castro Cer贸n</a>, <a href="/search/astro-ph?searchtype=author&query=Porto%2C+J+R+F">J. R. F. Porto</a>, <a href="/search/astro-ph?searchtype=author&query=Misra%2C+K">K. Misra</a>, <a href="/search/astro-ph?searchtype=author&query=De+Pasquale%2C+M">M. De Pasquale</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="2105.13145v1-abstract-short" style="display: inline;"> We present and perform a detailed analysis of multi-wavelength observations of \thisgrb, an optical bright GRB with an observed reverse shock (RS) signature. Observations of this GRB were acquired with the BOOTES-4 robotic telescope, the \fermi, and the \swift missions. Time-resolved spectroscopy of the prompt emission shows that changes to the peak energy (\Ep) tracks intensity and the low-energy… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2105.13145v1-abstract-full').style.display = 'inline'; document.getElementById('2105.13145v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2105.13145v1-abstract-full" style="display: none;"> We present and perform a detailed analysis of multi-wavelength observations of \thisgrb, an optical bright GRB with an observed reverse shock (RS) signature. Observations of this GRB were acquired with the BOOTES-4 robotic telescope, the \fermi, and the \swift missions. Time-resolved spectroscopy of the prompt emission shows that changes to the peak energy (\Ep) tracks intensity and the low-energy spectral index seems to follow the intensity for the first episode, whereas this tracking behavior is less clear during the second episode. The fit to the afterglow light curves shows that the early optical afterglow can be described with RS emission and is consistent with the thin shell scenario of the constant ambient medium. The late time afterglow decay is also consistent with the prediction of the external forward shock (FS) model. We determine the properties of the shocks, Lorentz factor, magnetization parameters, and ambient density of \thisgrb, and compare these parameters with another 12 GRBs, consistent with having RS produced by thin shells in an ISM-like medium. The value of the magnetization parameter ($R_{\rm B} \approx 18$) indicates a moderately magnetized baryonic dominant jet composition for \thisgrb. We also report the host galaxy photometric observations of \thisgrb obtained with 10.4m GTC, 3.5m CAHA, and 3.6m DOT telescopes and find the host (photo $z$ = $2.8^{+0.7}_{-0.9}$) to be a high mass, star-forming galaxy with a star formation rate of $20 \pm 10 \msun$ $\rm yr^{-1}$. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2105.13145v1-abstract-full').style.display = 'none'; document.getElementById('2105.13145v1-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 May, 2021; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> May 2021. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">27 pages, 16 figures, 12 tables, accepted for publication in MNRAS</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2105.09527">arXiv:2105.09527</a> <span> [<a href="https://arxiv.org/pdf/2105.09527">pdf</a>, <a href="https://arxiv.org/format/2105.09527">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/10.1007/s12036-021-09743-1">10.1007/s12036-021-09743-1 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Using collimated CZTI as all sky X-ray detector based on Earth Occultation Technique </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Singhal%2C+A">Akshat Singhal</a>, <a href="/search/astro-ph?searchtype=author&query=Srinivasan%2C+R">Rahul Srinivasan</a>, <a href="/search/astro-ph?searchtype=author&query=Bhalerao%2C+V">Varun Bhalerao</a>, <a href="/search/astro-ph?searchtype=author&query=Bhattacharya%2C+D">Dipankar Bhattacharya</a>, <a href="/search/astro-ph?searchtype=author&query=Rao%2C+A+R">A. R. Rao</a>, <a href="/search/astro-ph?searchtype=author&query=Vadawale%2C+S">Santosh Vadawale</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2105.09527v1-abstract-short" style="display: inline;"> All-sky monitors can measure the fluxes of astrophysical sources by measuring the changes in observed counts as the source is occulted by the Earth. Such measurements have typically been carried out by all-sky monitors like $\textit{CGRO}$-BATSE and $\textit{Fermi}$-GBM. We demonstrate for the first time the application of this technique to measure fluxes of sources using a collimated instrument:… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2105.09527v1-abstract-full').style.display = 'inline'; document.getElementById('2105.09527v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2105.09527v1-abstract-full" style="display: none;"> All-sky monitors can measure the fluxes of astrophysical sources by measuring the changes in observed counts as the source is occulted by the Earth. Such measurements have typically been carried out by all-sky monitors like $\textit{CGRO}$-BATSE and $\textit{Fermi}$-GBM. We demonstrate for the first time the application of this technique to measure fluxes of sources using a collimated instrument: the Cadmium Zinc Telluride detector on $\textit{AstroSat}$. Reliable flux measurements are obtained for the Crab nebula and pulsar, and for Cyg X-1 by carefully selecting the best occultation data sets. We demonstrate that CZTI can obtain such measurements for hard sources with intensities $\gtrsim1$Crab. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2105.09527v1-abstract-full').style.display = 'none'; document.getElementById('2105.09527v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 20 May, 2021; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> May 2021. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">Accepted in the "AstroSat - 5 years" special issue of the Journal of Astrophysics and Astronomy</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Journal of Astrophysics and Astronomy, Volume 42, Issue 2, article id.64, 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/2105.09525">arXiv:2105.09525</a> <span> [<a href="https://arxiv.org/pdf/2105.09525">pdf</a>, <a href="https://arxiv.org/format/2105.09525">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/10.1007/s12036-021-09763-x">10.1007/s12036-021-09763-x <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> The AstroSat Mass Model: Imaging and Flux studies of off-axis sources with CZTI </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Mate%2C+S">Sujay Mate</a>, <a href="/search/astro-ph?searchtype=author&query=Chattopadhyay%2C+T">Tanmoy Chattopadhyay</a>, <a href="/search/astro-ph?searchtype=author&query=Bhalerao%2C+V">Varun Bhalerao</a>, <a href="/search/astro-ph?searchtype=author&query=Aarthy%2C+E">E. Aarthy</a>, <a href="/search/astro-ph?searchtype=author&query=Balasubramanian%2C+A">Arvind Balasubramanian</a>, <a href="/search/astro-ph?searchtype=author&query=Bhattacharya%2C+D">Dipankar Bhattacharya</a>, <a href="/search/astro-ph?searchtype=author&query=Gupta%2C+S">Soumya Gupta</a>, <a href="/search/astro-ph?searchtype=author&query=Kutty%2C+K">Krishnan Kutty</a>, <a href="/search/astro-ph?searchtype=author&query=Mithun%2C+N+P+S">N. P. S. Mithun</a>, <a href="/search/astro-ph?searchtype=author&query=Palit%2C+S">Sourav Palit</a>, <a href="/search/astro-ph?searchtype=author&query=Rao%2C+A+R">A. R. Rao</a>, <a href="/search/astro-ph?searchtype=author&query=Saraogi%2C+D">Divita Saraogi</a>, <a href="/search/astro-ph?searchtype=author&query=Vadawale%2C+S">Santosh Vadawale</a>, <a href="/search/astro-ph?searchtype=author&query=Vibhute%2C+A">Ajay Vibhute</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2105.09525v1-abstract-short" style="display: inline;"> The Cadmium Zinc Telluride Imager (CZTI) on AstroSat is a hard X-ray coded-aperture mask instrument with a primary field of view of 4.6 x 4.6 degrees (FWHM). The instrument collimators become increasingly transparent at energies above $\sim$100 keV, making CZTI sensitive to radiation from the entire sky. While this has enabled CZTI to detect a large number of off-axis transient sources, calculatin… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2105.09525v1-abstract-full').style.display = 'inline'; document.getElementById('2105.09525v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2105.09525v1-abstract-full" style="display: none;"> The Cadmium Zinc Telluride Imager (CZTI) on AstroSat is a hard X-ray coded-aperture mask instrument with a primary field of view of 4.6 x 4.6 degrees (FWHM). The instrument collimators become increasingly transparent at energies above $\sim$100 keV, making CZTI sensitive to radiation from the entire sky. While this has enabled CZTI to detect a large number of off-axis transient sources, calculating the source flux or spectrum requires knowledge of the direction and energy dependent attenuation of the radiation incident upon the detector. Here, we present a GEANT4-based mass model of CZTI and AstroSat that can be used to simulate the satellite response to the incident radiation, and to calculate an effective "response file" for converting the source counts into fluxes and spectra. We provide details of the geometry and interaction physics, and validate the model by comparing the simulations of imaging and flux studies with observations. Spectroscopic validation of the mass model is discussed in a companion paper, Chattopadhyay 2021. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2105.09525v1-abstract-full').style.display = 'none'; document.getElementById('2105.09525v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 20 May, 2021; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> May 2021. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">Accepted in the "AstroSat - 5 years" special issue of the Journal of Astrophysics and Astronomy</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2105.09524">arXiv:2105.09524</a> <span> [<a href="https://arxiv.org/pdf/2105.09524">pdf</a>, <a href="https://arxiv.org/format/2105.09524">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="High Energy Astrophysical Phenomena">astro-ph.HE</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Instrumentation and Methods for Astrophysics">astro-ph.IM</span> </div> </div> <p class="title is-5 mathjax"> Revisiting the Earth's atmospheric scattering of X-ray/$纬$-rays and its effect on space observation: Implication for GRB spectral analysis </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Palit%2C+S">Sourav Palit</a>, <a href="/search/astro-ph?searchtype=author&query=Anumarlapudi%2C+A">Akash Anumarlapudi</a>, <a href="/search/astro-ph?searchtype=author&query=Bhalerao%2C+V">Varun Bhalerao</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2105.09524v1-abstract-short" style="display: inline;"> A considerable fraction of incident high-energy photons from astrophysical transients such as Gamma-Ray Bursts (GRBs) is Compton scattered by the Earth's atmosphere. These photons, sometimes referred to as the "reflection component", contribute to the signal detected by space-borne X-ray/$纬$-ray instruments. The effectiveness and reliability of source parameters such as position, flux, spectra, an… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2105.09524v1-abstract-full').style.display = 'inline'; document.getElementById('2105.09524v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2105.09524v1-abstract-full" style="display: none;"> A considerable fraction of incident high-energy photons from astrophysical transients such as Gamma-Ray Bursts (GRBs) is Compton scattered by the Earth's atmosphere. These photons, sometimes referred to as the "reflection component", contribute to the signal detected by space-borne X-ray/$纬$-ray instruments. The effectiveness and reliability of source parameters such as position, flux, spectra, and polarization, inferred by these instruments are therefore highly dependent on the accurate estimation of this scattered component. Current missions use dedicated response matrices to account for these effects. However, these databases are not readily adaptable for other missions, including many upcoming transient search and gravitational wave high-energy Electromagnetic counterpart detectors. Furthermore, possible systematic effects in these complex simulations have not been thoroughly examined and verified in the literature. We are in the process of investigation of the effect with detailed Monte Carlo simulations in GEANT4 for a Low Earth Orbit (LEO) X-ray detector. Here, we discuss the outcome of our simulation in form of the Atmospheric Response Matrix (ARM) and its implications of any systematic errors in the determination of source spectral characteristics. We intend to apply our results in data processing and analysis for AstroSat-CZTI observation of such sources in near future. Our simulation output and source codes will be made publicly available for use by a large number of upcoming high energy transient missions, as well as for scrutiny and systematic comparisons with other missions <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2105.09524v1-abstract-full').style.display = 'none'; document.getElementById('2105.09524v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 20 May, 2021; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> May 2021. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">Accepted in the "AstroSat - 5 years" special issue of the Journal of Astrophysics and Astronomy</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2105.05067">arXiv:2105.05067</a> <span> [<a href="https://arxiv.org/pdf/2105.05067">pdf</a>, <a href="https://arxiv.org/format/2105.05067">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/10.1038/s41550-021-01428-7">10.1038/s41550-021-01428-7 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Discovery and confirmation of the shortest gamma ray burst from a collapsar </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Ahumada%2C+T">Tomas Ahumada</a>, <a href="/search/astro-ph?searchtype=author&query=Singer%2C+L+P">Leo P. Singer</a>, <a href="/search/astro-ph?searchtype=author&query=Anand%2C+S">Shreya Anand</a>, <a href="/search/astro-ph?searchtype=author&query=Coughlin%2C+M+W">Michael W. Coughlin</a>, <a href="/search/astro-ph?searchtype=author&query=Kasliwal%2C+M+M">Mansi M. Kasliwal</a>, <a href="/search/astro-ph?searchtype=author&query=Ryan%2C+G">Geoffrey Ryan</a>, <a href="/search/astro-ph?searchtype=author&query=Andreoni%2C+I">Igor Andreoni</a>, <a href="/search/astro-ph?searchtype=author&query=Cenko%2C+S+B">S. Bradley Cenko</a>, <a href="/search/astro-ph?searchtype=author&query=Fremling%2C+C">Christoffer Fremling</a>, <a href="/search/astro-ph?searchtype=author&query=Kumar%2C+H">Harsh Kumar</a>, <a href="/search/astro-ph?searchtype=author&query=Pang%2C+P+T+H">Peter T. H. Pang</a>, <a href="/search/astro-ph?searchtype=author&query=Burns%2C+E">Eric Burns</a>, <a href="/search/astro-ph?searchtype=author&query=Cunningham%2C+V">Virginia Cunningham</a>, <a href="/search/astro-ph?searchtype=author&query=Dichiara%2C+S">Simone Dichiara</a>, <a href="/search/astro-ph?searchtype=author&query=Dietrich%2C+T">Tim Dietrich</a>, <a href="/search/astro-ph?searchtype=author&query=Svinkin%2C+D+S">Dmitry S. Svinkin</a>, <a href="/search/astro-ph?searchtype=author&query=Almualla%2C+M">Mouza Almualla</a>, <a href="/search/astro-ph?searchtype=author&query=Castro-Tirado%2C+A+J">Alberto J. Castro-Tirado</a>, <a href="/search/astro-ph?searchtype=author&query=De%2C+K">Kishalay De</a>, <a href="/search/astro-ph?searchtype=author&query=Dunwoody%2C+R">Rachel Dunwoody</a>, <a href="/search/astro-ph?searchtype=author&query=Gatkine%2C+P">Pradip Gatkine</a>, <a href="/search/astro-ph?searchtype=author&query=Hammerstein%2C+E">Erica Hammerstein</a>, <a href="/search/astro-ph?searchtype=author&query=Iyyani%2C+S">Shabnam Iyyani</a>, <a href="/search/astro-ph?searchtype=author&query=Mangan%2C+J">Joseph Mangan</a>, <a href="/search/astro-ph?searchtype=author&query=Perley%2C+D">Dan Perley</a> , et al. (32 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="2105.05067v2-abstract-short" style="display: inline;"> Gamma-ray bursts (GRBs) are among the brightest and most energetic events in the universe. The duration and hardness distribution of GRBs has two clusters, now understood to reflect (at least) two different progenitors. Short-hard GRBs (SGRBs; T90 <2 s) arise from compact binary mergers, while long-soft GRBs (LGRBs; T90 >2 s) have been attributed to the collapse of peculiar massive stars (collapsa… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2105.05067v2-abstract-full').style.display = 'inline'; document.getElementById('2105.05067v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2105.05067v2-abstract-full" style="display: none;"> Gamma-ray bursts (GRBs) are among the brightest and most energetic events in the universe. The duration and hardness distribution of GRBs has two clusters, now understood to reflect (at least) two different progenitors. Short-hard GRBs (SGRBs; T90 <2 s) arise from compact binary mergers, while long-soft GRBs (LGRBs; T90 >2 s) have been attributed to the collapse of peculiar massive stars (collapsars). The discovery of SN 1998bw/GRB 980425 marked the first association of a LGRB with a collapsar and AT 2017gfo/GRB 170817A/GW170817 marked the first association of a SGRB with a binary neutron star merger, producing also gravitational wave (GW). Here, we present the discovery of ZTF20abwysqy (AT2020scz), a fast-fading optical transient in the Fermi Satellite and the InterPlanetary Network (IPN) localization regions of GRB 200826A; X-ray and radio emission further confirm that this is the afterglow. Follow-up imaging (at rest-frame 16.5 days) reveals excess emission above the afterglow that cannot be explained as an underlying kilonova (KN), but is consistent with being the supernova (SN). Despite the GRB duration being short (rest-frame T90 of 0.65 s), our panchromatic follow-up data confirms a collapsar origin. GRB 200826A is the shortest LGRB found with an associated collapsar; it appears to sit on the brink between a successful and a failed collapsar. Our discovery is consistent with the hypothesis that most collapsars fail to produce ultra-relativistic jets. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2105.05067v2-abstract-full').style.display = 'none'; document.getElementById('2105.05067v2-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 May, 2021; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 11 May, 2021; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> May 2021. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">submitted to Nature Astronomy</span> </p> </li> </ol> <nav class="pagination is-small is-centered breathe-horizontal" role="navigation" aria-label="pagination"> <a href="" class="pagination-previous is-invisible">Previous </a> <a href="/search/?searchtype=author&query=Bhalerao%2C+V&start=50" class="pagination-next" >Next </a> <ul class="pagination-list"> <li> <a href="/search/?searchtype=author&query=Bhalerao%2C+V&start=0" class="pagination-link is-current" aria-label="Goto page 1">1 </a> </li> <li> <a href="/search/?searchtype=author&query=Bhalerao%2C+V&start=50" class="pagination-link " aria-label="Page 2" aria-current="page">2 </a> </li> <li> <a href="/search/?searchtype=author&query=Bhalerao%2C+V&start=100" class="pagination-link " aria-label="Page 3" aria-current="page">3 </a> </li> </ul> </nav> <div class="is-hidden-tablet">  <span class="help" style="display: inline-block;"><a href="https://github.com/arXiv/arxiv-search/releases">Search v0.5.6 released 2020-02-24</a>  </span> </div> </div> </main> <footer> <div class="columns is-desktop" role="navigation" aria-label="Secondary">  <div class="column"> <div class="columns"> <div class="column"> <ul class="nav-spaced"> <li><a href="https://info.arxiv.org/about">About</a></li> <li><a href="https://info.arxiv.org/help">Help</a></li> </ul> </div> <div class="column"> <ul class="nav-spaced"> <li> <svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 512 512" class="icon filter-black" role="presentation"><title>contact arXiv</title><desc>Click here to contact arXiv</desc><path d="M502.3 190.8c3.9-3.1 9.7-.2 9.7 4.7V400c0 26.5-21.5 48-48 48H48c-26.5 0-48-21.5-48-48V195.6c0-5 5.7-7.8 9.7-4.7 22.4 17.4 52.1 39.5 154.1 113.6 21.1 15.4 56.7 47.8 92.2 47.6 35.7.3 72-32.8 92.3-47.6 102-74.1 131.6-96.3 154-113.7zM256 320c23.2.4 56.6-29.2 73.4-41.4 132.7-96.3 142.8-104.7 173.4-128.7 5.8-4.5 9.2-11.5 9.2-18.9v-19c0-26.5-21.5-48-48-48H48C21.5 64 0 85.5 0 112v19c0 7.4 3.4 14.3 9.2 18.9 30.6 23.9 40.7 32.4 173.4 128.7 16.8 12.2 50.2 41.8 73.4 41.4z"/></svg> <a href="https://info.arxiv.org/help/contact.html"> Contact</a> </li> <li> <svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 512 512" class="icon filter-black" role="presentation"><title>subscribe to arXiv mailings</title><desc>Click here to subscribe</desc><path d="M476 3.2L12.5 270.6c-18.1 10.4-15.8 35.6 2.2 43.2L121 358.4l287.3-253.2c5.5-4.9 13.3 2.6 8.6 8.3L176 407v80.5c0 23.6 28.5 32.9 42.5 15.8L282 426l124.6 52.2c14.2 6 30.4-2.9 33-18.2l72-432C515 7.8 493.3-6.8 476 3.2z"/></svg> <a href="https://info.arxiv.org/help/subscribe"> Subscribe</a> </li> </ul> </div> </div> </div>   <div class="column"> <div class="columns"> <div class="column"> <ul class="nav-spaced"> <li><a href="https://info.arxiv.org/help/license/index.html">Copyright</a></li> <li><a href="https://info.arxiv.org/help/policies/privacy_policy.html">Privacy Policy</a></li> </ul> </div> <div class="column sorry-app-links"> <ul class="nav-spaced"> <li><a href="https://info.arxiv.org/help/web_accessibility.html">Web Accessibility Assistance</a></li> <li> <p class="help"> <a class="a11y-main-link" href="https://status.arxiv.org" target="_blank">arXiv Operational Status <svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 256 512" class="icon filter-dark_grey" role="presentation"><path d="M224.3 273l-136 136c-9.4 9.4-24.6 9.4-33.9 0l-22.6-22.6c-9.4-9.4-9.4-24.6 0-33.9l96.4-96.4-96.4-96.4c-9.4-9.4-9.4-24.6 0-33.9L54.3 103c9.4-9.4 24.6-9.4 33.9 0l136 136c9.5 9.4 9.5 24.6.1 34z"/></svg></a><br> Get status notifications via <a class="is-link" href="https://subscribe.sorryapp.com/24846f03/email/new" target="_blank"><svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 512 512" class="icon filter-black" role="presentation"><path d="M502.3 190.8c3.9-3.1 9.7-.2 9.7 4.7V400c0 26.5-21.5 48-48 48H48c-26.5 0-48-21.5-48-48V195.6c0-5 5.7-7.8 9.7-4.7 22.4 17.4 52.1 39.5 154.1 113.6 21.1 15.4 56.7 47.8 92.2 47.6 35.7.3 72-32.8 92.3-47.6 102-74.1 131.6-96.3 154-113.7zM256 320c23.2.4 56.6-29.2 73.4-41.4 132.7-96.3 142.8-104.7 173.4-128.7 5.8-4.5 9.2-11.5 9.2-18.9v-19c0-26.5-21.5-48-48-48H48C21.5 64 0 85.5 0 112v19c0 7.4 3.4 14.3 9.2 18.9 30.6 23.9 40.7 32.4 173.4 128.7 16.8 12.2 50.2 41.8 73.4 41.4z"/></svg>email</a> or <a class="is-link" href="https://subscribe.sorryapp.com/24846f03/slack/new" target="_blank"><svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 448 512" class="icon filter-black" role="presentation"><path d="M94.12 315.1c0 25.9-21.16 47.06-47.06 47.06S0 341 0 315.1c0-25.9 21.16-47.06 47.06-47.06h47.06v47.06zm23.72 0c0-25.9 21.16-47.06 47.06-47.06s47.06 21.16 47.06 47.06v117.84c0 25.9-21.16 47.06-47.06 47.06s-47.06-21.16-47.06-47.06V315.1zm47.06-188.98c-25.9 0-47.06-21.16-47.06-47.06S139 32 164.9 32s47.06 21.16 47.06 47.06v47.06H164.9zm0 23.72c25.9 0 47.06 21.16 47.06 47.06s-21.16 47.06-47.06 47.06H47.06C21.16 243.96 0 222.8 0 196.9s21.16-47.06 47.06-47.06H164.9zm188.98 47.06c0-25.9 21.16-47.06 47.06-47.06 25.9 0 47.06 21.16 47.06 47.06s-21.16 47.06-47.06 47.06h-47.06V196.9zm-23.72 0c0 25.9-21.16 47.06-47.06 47.06-25.9 0-47.06-21.16-47.06-47.06V79.06c0-25.9 21.16-47.06 47.06-47.06 25.9 0 47.06 21.16 47.06 47.06V196.9zM283.1 385.88c25.9 0 47.06 21.16 47.06 47.06 0 25.9-21.16 47.06-47.06 47.06-25.9 0-47.06-21.16-47.06-47.06v-47.06h47.06zm0-23.72c-25.9 0-47.06-21.16-47.06-47.06 0-25.9 21.16-47.06 47.06-47.06h117.84c25.9 0 47.06 21.16 47.06 47.06 0 25.9-21.16 47.06-47.06 47.06H283.1z"/></svg>slack</a> </p> </li> </ul> </div> </div> </div>  </div> </footer> <script src="https://static.arxiv.org/static/base/1.0.0a5/js/member_acknowledgement.js"></script> </body> </html>

CINXE.COM

Search | arXiv e-print repository