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</div> <div class="control"> <button class="button is-small is-link">Go</button> </div> </div> </form> </div> </div> <nav class="pagination is-small is-centered breathe-horizontal" role="navigation" aria-label="pagination"> <a href="" class="pagination-previous is-invisible">Previous </a> <a href="/search/?searchtype=author&query=Gompertz%2C+B&start=50" class="pagination-next" >Next </a> <ul class="pagination-list"> <li> <a href="/search/?searchtype=author&query=Gompertz%2C+B&start=0" class="pagination-link is-current" aria-label="Goto page 1">1 </a> </li> <li> <a href="/search/?searchtype=author&query=Gompertz%2C+B&start=50" class="pagination-link " aria-label="Page 2" aria-current="page">2 </a> </li> </ul> </nav> <ol class="breathe-horizontal" start="1"> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2411.04793">arXiv:2411.04793</a> <span> [<a href="https://arxiv.org/pdf/2411.04793">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="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"> Rubin ToO 2024: Envisioning the Vera C. Rubin Observatory LSST Target of Opportunity program </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=Margutti%2C+R">Raffaella Margutti</a>, <a href="/search/astro-ph?searchtype=author&query=Banovetz%2C+J">John Banovetz</a>, <a href="/search/astro-ph?searchtype=author&query=Greenstreet%2C+S">Sarah Greenstreet</a>, <a href="/search/astro-ph?searchtype=author&query=Hebert%2C+C">Claire-Alice Hebert</a>, <a href="/search/astro-ph?searchtype=author&query=Lister%2C+T">Tim Lister</a>, <a href="/search/astro-ph?searchtype=author&query=Palmese%2C+A">Antonella Palmese</a>, <a href="/search/astro-ph?searchtype=author&query=Piranomonte%2C+S">Silvia Piranomonte</a>, <a href="/search/astro-ph?searchtype=author&query=Smartt%2C+S+J">S. J. Smartt</a>, <a href="/search/astro-ph?searchtype=author&query=Smith%2C+G+P">Graham P. Smith</a>, <a href="/search/astro-ph?searchtype=author&query=Stein%2C+R">Robert Stein</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=Auchettl%2C+K">Katie Auchettl</a>, <a href="/search/astro-ph?searchtype=author&query=Bannister%2C+M+T">Michele T. Bannister</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=Bloom%2C+J+S">Joshua S. Bloom</a>, <a href="/search/astro-ph?searchtype=author&query=Bolin%2C+B+T">Bryce T. Bolin</a>, <a href="/search/astro-ph?searchtype=author&query=Bom%2C+C+R">Clecio R. Bom</a>, <a href="/search/astro-ph?searchtype=author&query=Brethauer%2C+D">Daniel Brethauer</a>, <a href="/search/astro-ph?searchtype=author&query=Brucker%2C+M+J">Melissa J. Brucker</a>, <a href="/search/astro-ph?searchtype=author&query=Buckley%2C+D+A+H">David A. H. Buckley</a>, <a href="/search/astro-ph?searchtype=author&query=Chandra%2C+P">Poonam Chandra</a>, <a href="/search/astro-ph?searchtype=author&query=Chornock%2C+R">Ryan Chornock</a>, <a href="/search/astro-ph?searchtype=author&query=Christensen%2C+E">Eric Christensen</a> , et al. (64 additional authors not shown) </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2411.04793v1-abstract-short" style="display: inline;"> The Legacy Survey of Space and Time (LSST) at Vera C. Rubin Observatory is planned to begin in the Fall of 2025. The LSST survey cadence has been designed via a community-driven process regulated by the Survey Cadence Optimization Committee (SCOC), which recommended up to 3% of the observing time to carry out Target of Opportunity (ToO) observations. Experts from the scientific community, Rubin Ob… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2411.04793v1-abstract-full').style.display = 'inline'; document.getElementById('2411.04793v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2411.04793v1-abstract-full" style="display: none;"> The Legacy Survey of Space and Time (LSST) at Vera C. Rubin Observatory is planned to begin in the Fall of 2025. The LSST survey cadence has been designed via a community-driven process regulated by the Survey Cadence Optimization Committee (SCOC), which recommended up to 3% of the observing time to carry out Target of Opportunity (ToO) observations. Experts from the scientific community, Rubin Observatory personnel, and members of the SCOC were brought together to deliver a recommendation for the implementation of the ToO program during a workshop held in March 2024. Four main science cases were identified: gravitational wave multi-messenger astronomy, high energy neutrinos, Galactic supernovae, and small potentially hazardous asteroids possible impactors. Additional science cases were identified and briefly addressed in the documents, including lensed or poorly localized gamma-ray bursts and twilight discoveries. Trigger prioritization, automated response, and detailed strategies were discussed for each science case. This document represents the outcome of the Rubin ToO 2024 workshop, with additional contributions from members of the Rubin Science Collaborations. The implementation of the selection criteria and strategies presented in this document has been endorsed in the SCOC Phase 3 Recommendations document (PSTN-056). Although the ToO program is still to be finalized, this document serves as a baseline plan for ToO observations with the Rubin Observatory. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2411.04793v1-abstract-full').style.display = 'none'; document.getElementById('2411.04793v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 7 November, 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/2409.07686">arXiv:2409.07686</a> <span> [<a href="https://arxiv.org/pdf/2409.07686">pdf</a>, <a href="https://arxiv.org/format/2409.07686">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/ad85e9">10.3847/2041-8213/ad85e9 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> The early radio afterglow of short GRB 230217A </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Anderson%2C+G+E">G. E. Anderson</a>, <a href="/search/astro-ph?searchtype=author&query=Schroeder%2C+G">G. Schroeder</a>, <a href="/search/astro-ph?searchtype=author&query=van+der+Horst%2C+A+J">A. J. van der Horst</a>, <a href="/search/astro-ph?searchtype=author&query=Rhodes%2C+L">L. Rhodes</a>, <a href="/search/astro-ph?searchtype=author&query=Rowlinson%2C+A">A. Rowlinson</a>, <a href="/search/astro-ph?searchtype=author&query=Bahramian%2C+A">A. Bahramian</a>, <a href="/search/astro-ph?searchtype=author&query=Chastain%2C+S+I">S. I. Chastain</a>, <a href="/search/astro-ph?searchtype=author&query=Gompertz%2C+B+P">B. P. Gompertz</a>, <a href="/search/astro-ph?searchtype=author&query=Hancock%2C+P+J">P. J. Hancock</a>, <a href="/search/astro-ph?searchtype=author&query=Laskar%2C+T">T. Laskar</a>, <a href="/search/astro-ph?searchtype=author&query=Leung%2C+J+K">J. K. Leung</a>, <a href="/search/astro-ph?searchtype=author&query=Wijers%2C+R+A+M+J">R. A. M. J. Wijers</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="2409.07686v2-abstract-short" style="display: inline;"> We present the radio afterglow of short gamma-ray burst (GRB) 230217A, which was detected less than 1 day after the gamma-ray prompt emission with the Australia Telescope Compact Array (ATCA) and the Karl G. Jansky Very Large Array (VLA). The ATCA rapid-response system automatically triggered an observation of GRB 230217A following its detection by the Neil Gehrels Swift Observatory and began obse… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2409.07686v2-abstract-full').style.display = 'inline'; document.getElementById('2409.07686v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2409.07686v2-abstract-full" style="display: none;"> We present the radio afterglow of short gamma-ray burst (GRB) 230217A, which was detected less than 1 day after the gamma-ray prompt emission with the Australia Telescope Compact Array (ATCA) and the Karl G. Jansky Very Large Array (VLA). The ATCA rapid-response system automatically triggered an observation of GRB 230217A following its detection by the Neil Gehrels Swift Observatory and began observing the event just 32 minutes post-burst at 5.5 and 9 GHz for 7 hours. Dividing the 7-hour observation into three time-binned images allowed us to obtain radio detections with logarithmic central times of 1, 2.8 and 5.2 hours post-burst, the first of which represents the earliest radio detection of any GRB to date. The decline of the light curve is consistent with reverse shock emission if the observing bands are below the spectral peak and not affected by synchrotron self-absorption. This makes GRB 230217A the fifth short GRB with radio detections attributed to a reverse shock at early times ($<1$ day post-burst). Following brightness temperature arguments, we have used our early radio detections to place the highest minimum Lorentz factor ($螕_{min} > 50$ at $\sim1$ hour) constraints on a GRB in the radio band. Our results demonstrate the importance of rapid radio follow-up observations with long integrations and good sensitivity for detecting the fast-evolving radio emission from short GRBs and probing their reverse shocks. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2409.07686v2-abstract-full').style.display = 'none'; document.getElementById('2409.07686v2-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 10 November, 2024; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 11 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">11 pages, 3 figures, submitted to ApJL</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> 2024 ApJL 975 L13 </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2409.02181">arXiv:2409.02181</a> <span> [<a href="https://arxiv.org/pdf/2409.02181">pdf</a>, <a href="https://arxiv.org/format/2409.02181">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="High Energy Astrophysical Phenomena">astro-ph.HE</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Cosmology and Nongalactic Astrophysics">astro-ph.CO</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="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"> Quasi-periodic X-ray eruptions years after a nearby tidal disruption event </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Nicholl%2C+M">M. Nicholl</a>, <a href="/search/astro-ph?searchtype=author&query=Pasham%2C+D+R">D. R. Pasham</a>, <a href="/search/astro-ph?searchtype=author&query=Mummery%2C+A">A. Mummery</a>, <a href="/search/astro-ph?searchtype=author&query=Guolo%2C+M">M. Guolo</a>, <a href="/search/astro-ph?searchtype=author&query=Gendreau%2C+K">K. Gendreau</a>, <a href="/search/astro-ph?searchtype=author&query=Dewangan%2C+G+C">G. C. Dewangan</a>, <a href="/search/astro-ph?searchtype=author&query=Ferrara%2C+E+C">E. C. Ferrara</a>, <a href="/search/astro-ph?searchtype=author&query=Remillard%2C+R">R. Remillard</a>, <a href="/search/astro-ph?searchtype=author&query=Bonnerot%2C+C">C. Bonnerot</a>, <a href="/search/astro-ph?searchtype=author&query=Chakraborty%2C+J">J. Chakraborty</a>, <a href="/search/astro-ph?searchtype=author&query=Hajela%2C+A">A. Hajela</a>, <a href="/search/astro-ph?searchtype=author&query=Dhillon%2C+V+S">V. S. Dhillon</a>, <a href="/search/astro-ph?searchtype=author&query=Gillan%2C+A+F">A. F. Gillan</a>, <a href="/search/astro-ph?searchtype=author&query=Greenwood%2C+J">J. Greenwood</a>, <a href="/search/astro-ph?searchtype=author&query=Huber%2C+M+E">M. E. Huber</a>, <a href="/search/astro-ph?searchtype=author&query=Janiuk%2C+A">A. Janiuk</a>, <a href="/search/astro-ph?searchtype=author&query=Salvesen%2C+G">G. Salvesen</a>, <a href="/search/astro-ph?searchtype=author&query=van+Velzen%2C+S">S. van Velzen</a>, <a href="/search/astro-ph?searchtype=author&query=Aamer%2C+A">A. Aamer</a>, <a href="/search/astro-ph?searchtype=author&query=Alexander%2C+K+D">K. D. Alexander</a>, <a href="/search/astro-ph?searchtype=author&query=Angus%2C+C+R">C. R. Angus</a>, <a href="/search/astro-ph?searchtype=author&query=Arzoumanian%2C+Z">Z. Arzoumanian</a>, <a href="/search/astro-ph?searchtype=author&query=Auchettl%2C+K">K. Auchettl</a>, <a href="/search/astro-ph?searchtype=author&query=Berger%2C+E">E. Berger</a>, <a href="/search/astro-ph?searchtype=author&query=de+Boer%2C+T">T. de Boer</a> , et al. (39 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="2409.02181v1-abstract-short" style="display: inline;"> Quasi-periodic Eruptions (QPEs) are luminous bursts of soft X-rays from the nuclei of galaxies, repeating on timescales of hours to weeks. The mechanism behind these rare systems is uncertain, but most theories involve accretion disks around supermassive black holes (SMBHs), undergoing instabilities or interacting with a stellar object in a close orbit. It has been suggested that this disk could b… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2409.02181v1-abstract-full').style.display = 'inline'; document.getElementById('2409.02181v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2409.02181v1-abstract-full" style="display: none;"> Quasi-periodic Eruptions (QPEs) are luminous bursts of soft X-rays from the nuclei of galaxies, repeating on timescales of hours to weeks. The mechanism behind these rare systems is uncertain, but most theories involve accretion disks around supermassive black holes (SMBHs), undergoing instabilities or interacting with a stellar object in a close orbit. It has been suggested that this disk could be created when the SMBH disrupts a passing star, implying that many QPEs should be preceded by observable tidal disruption events (TDEs). Two known QPE sources show long-term decays in quiescent luminosity consistent with TDEs, and two observed TDEs have exhibited X-ray flares consistent with individual eruptions. TDEs and QPEs also occur preferentially in similar galaxies. However, no confirmed repeating QPEs have been associated with a spectroscopically confirmed TDE or an optical TDE observed at peak brightness. Here we report the detection of nine X-ray QPEs with a mean recurrence time of approximately 48 hours from AT2019qiz, a nearby and extensively studied optically-selected TDE. We detect and model the X-ray, ultraviolet and optical emission from the accretion disk, and show that an orbiting body colliding with this disk provides a plausible explanation for the QPEs. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2409.02181v1-abstract-full').style.display = 'none'; document.getElementById('2409.02181v1-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">originally announced</span> September 2024. </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2406.02334">arXiv:2406.02334</a> <span> [<a href="https://arxiv.org/pdf/2406.02334">pdf</a>, <a href="https://arxiv.org/format/2406.02334">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"> $\textit{Kilonova Seekers}$: the GOTO project for real-time citizen science in time-domain astrophysics </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Killestein%2C+T+L">T. L. Killestein</a>, <a href="/search/astro-ph?searchtype=author&query=Kelsey%2C+L">L. Kelsey</a>, <a href="/search/astro-ph?searchtype=author&query=Wickens%2C+E">E. Wickens</a>, <a href="/search/astro-ph?searchtype=author&query=Nuttall%2C+L">L. Nuttall</a>, <a href="/search/astro-ph?searchtype=author&query=Lyman%2C+J">J. Lyman</a>, <a href="/search/astro-ph?searchtype=author&query=Krawczyk%2C+C">C. Krawczyk</a>, <a href="/search/astro-ph?searchtype=author&query=Ackley%2C+K">K. Ackley</a>, <a href="/search/astro-ph?searchtype=author&query=Dyer%2C+M+J">M. J. Dyer</a>, <a href="/search/astro-ph?searchtype=author&query=Jim%C3%A9nez-Ibarra%2C+F">F. Jim茅nez-Ibarra</a>, <a href="/search/astro-ph?searchtype=author&query=Ulaczyk%2C+K">K. Ulaczyk</a>, <a href="/search/astro-ph?searchtype=author&query=O%27Neill%2C+D">D. O'Neill</a>, <a href="/search/astro-ph?searchtype=author&query=Kumar%2C+A">A. Kumar</a>, <a href="/search/astro-ph?searchtype=author&query=Steeghs%2C+D">D. Steeghs</a>, <a href="/search/astro-ph?searchtype=author&query=Galloway%2C+D+K">D. K. Galloway</a>, <a href="/search/astro-ph?searchtype=author&query=Dhillon%2C+V+S">V. S. Dhillon</a>, <a href="/search/astro-ph?searchtype=author&query=O%27Brien%2C+P">P. O'Brien</a>, <a href="/search/astro-ph?searchtype=author&query=Ramsay%2C+G">G. Ramsay</a>, <a href="/search/astro-ph?searchtype=author&query=Noysena%2C+K">K. Noysena</a>, <a href="/search/astro-ph?searchtype=author&query=Kotak%2C+R">R. Kotak</a>, <a href="/search/astro-ph?searchtype=author&query=Breton%2C+R+P">R. P. Breton</a>, <a href="/search/astro-ph?searchtype=author&query=Pall%C3%A9%2C+E">E. Pall茅</a>, <a href="/search/astro-ph?searchtype=author&query=Pollacco%2C+D">D. Pollacco</a>, <a href="/search/astro-ph?searchtype=author&query=Awiphan%2C+S">S. Awiphan</a>, <a href="/search/astro-ph?searchtype=author&query=Belkin%2C+S">S. Belkin</a>, <a href="/search/astro-ph?searchtype=author&query=Chote%2C+P">P. Chote</a> , et al. (29 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="2406.02334v2-abstract-short" style="display: inline;"> Time-domain astrophysics continues to grow rapidly, with the inception of new surveys drastically increasing data volumes. Democratised, distributed approaches to training sets for machine learning classifiers are crucial to make the most of this torrent of discovery -- with citizen science approaches proving effective at meeting these requirements. In this paper, we describe the creation of and t… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2406.02334v2-abstract-full').style.display = 'inline'; document.getElementById('2406.02334v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2406.02334v2-abstract-full" style="display: none;"> Time-domain astrophysics continues to grow rapidly, with the inception of new surveys drastically increasing data volumes. Democratised, distributed approaches to training sets for machine learning classifiers are crucial to make the most of this torrent of discovery -- with citizen science approaches proving effective at meeting these requirements. In this paper, we describe the creation of and the initial results from the $\textit{Kilonova Seekers}$ citizen science project, built to find transient phenomena from the GOTO telescopes in near real-time. $\textit{Kilonova Seekers}$ launched in July 2023 and received over 600,000 classifications from approximately 2,000 volunteers over the course of the LIGO-Virgo-KAGRA O4a observing run. During this time, the project has yielded 20 discoveries, generated a `gold-standard' training set of 17,682 detections for augmenting deep-learned classifiers, and measured the performance and biases of Zooniverse volunteers on real-bogus classification. This project will continue throughout the lifetime of GOTO, pushing candidates at ever-greater cadence, and directly facilitate the next-generation classification algorithms currently in development. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2406.02334v2-abstract-full').style.display = 'none'; document.getElementById('2406.02334v2-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 July, 2024; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 4 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">20 pages, 15 figures. Accepted 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/2404.16350">arXiv:2404.16350</a> <span> [<a href="https://arxiv.org/pdf/2404.16350">pdf</a>, <a href="https://arxiv.org/format/2404.16350">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="High Energy Astrophysical Phenomena">astro-ph.HE</span> </div> </div> <p class="title is-5 mathjax"> The fast X-ray transient EP240315a: a z ~ 5 gamma-ray burst in a Lyman continuum leaking galaxy </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Levan%2C+A+J">Andrew J. Levan</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=Saccardi%2C+A">Andrea Saccardi</a>, <a href="/search/astro-ph?searchtype=author&query=Malesani%2C+D+B">Daniele Bj酶rn Malesani</a>, <a href="/search/astro-ph?searchtype=author&query=Tanvir%2C+N+R">Nial R. Tanvir</a>, <a href="/search/astro-ph?searchtype=author&query=Izzo%2C+L">Luca Izzo</a>, <a href="/search/astro-ph?searchtype=author&query=Heintz%2C+K+E">Kasper E. Heintz</a>, <a href="/search/astro-ph?searchtype=author&query=S%C3%A1nchez%2C+D+M">Daniel Mata S谩nchez</a>, <a href="/search/astro-ph?searchtype=author&query=Quirola-V%C3%A1squez%2C+J">Jonathan Quirola-V谩squez</a>, <a href="/search/astro-ph?searchtype=author&query=Torres%2C+M+A+P">Manuel A. P. Torres</a>, <a href="/search/astro-ph?searchtype=author&query=Vergani%2C+S+D">Susanna D. Vergani</a>, <a href="/search/astro-ph?searchtype=author&query=Schulze%2C+S">Steve Schulze</a>, <a href="/search/astro-ph?searchtype=author&query=Rossi%2C+A">Andrea Rossi</a>, <a href="/search/astro-ph?searchtype=author&query=D%27Avanzo%2C+P">Paolo D'Avanzo</a>, <a href="/search/astro-ph?searchtype=author&query=Gompertz%2C+B">Benjamin Gompertz</a>, <a href="/search/astro-ph?searchtype=author&query=Martin-Carrillo%2C+A">Antonio Martin-Carrillo</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=Schneider%2C+B">Benjamin Schneider</a>, <a href="/search/astro-ph?searchtype=author&query=Yuan%2C+W">Weimin Yuan</a>, <a href="/search/astro-ph?searchtype=author&query=Ling%2C+Z">Zhixing Ling</a>, <a href="/search/astro-ph?searchtype=author&query=Zhang%2C+W">Wenjie Zhang</a>, <a href="/search/astro-ph?searchtype=author&query=Mao%2C+X">Xuan Mao</a>, <a href="/search/astro-ph?searchtype=author&query=Liu%2C+Y">Yuan Liu</a>, <a href="/search/astro-ph?searchtype=author&query=Sun%2C+H">Hui Sun</a>, <a href="/search/astro-ph?searchtype=author&query=Xu%2C+D">Dong Xu</a> , et al. (51 additional authors not shown) </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2404.16350v1-abstract-short" style="display: inline;"> The nature of the minute-to-hour long Fast X-ray Transients (FXTs) localised by telescopes such as Chandra, Swift, and XMM-Newton remains mysterious, with numerous models suggested for the events. Here, we report multi-wavelength observations of EP240315a, a 1600 s long transient detected by the Einstein Probe, showing it to have a redshift of z=4.859. We measure a low column density of neutral hy… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2404.16350v1-abstract-full').style.display = 'inline'; document.getElementById('2404.16350v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2404.16350v1-abstract-full" style="display: none;"> The nature of the minute-to-hour long Fast X-ray Transients (FXTs) localised by telescopes such as Chandra, Swift, and XMM-Newton remains mysterious, with numerous models suggested for the events. Here, we report multi-wavelength observations of EP240315a, a 1600 s long transient detected by the Einstein Probe, showing it to have a redshift of z=4.859. We measure a low column density of neutral hydrogen, indicating that the event is embedded in a low-density environment, further supported by direct detection of leaking ionising Lyman-continuum. The observed properties are consistent with EP240315a being a long-duration gamma-ray burst, and these observations support an interpretation in which a significant fraction of the FXT population are lower-luminosity examples of similar events. Such transients are detectable at high redshifts by the Einstein Probe and, in the (near) future, out to even larger distances by SVOM, THESEUS, and Athena, providing samples of events into the epoch of reionisation. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2404.16350v1-abstract-full').style.display = 'none'; document.getElementById('2404.16350v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 25 April, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> April 2024. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">41 pages, 7 figures, 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/2403.18076">arXiv:2403.18076</a> <span> [<a href="https://arxiv.org/pdf/2403.18076">pdf</a>, <a href="https://arxiv.org/format/2403.18076">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"> Magnetars as Powering Sources of Gamma-Ray Burst Associated Supernovae, and Unsupervised Clustering of Cosmic Explosions </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Kumar%2C+A">Amit Kumar</a>, <a href="/search/astro-ph?searchtype=author&query=Sharma%2C+K">Kaushal Sharma</a>, <a href="/search/astro-ph?searchtype=author&query=Vink%C3%B3%2C+J">Jozsef Vink贸</a>, <a href="/search/astro-ph?searchtype=author&query=Steeghs%2C+D">Danny Steeghs</a>, <a href="/search/astro-ph?searchtype=author&query=Gompertz%2C+B">Benjamin Gompertz</a>, <a href="/search/astro-ph?searchtype=author&query=Lyman%2C+J">Joseph Lyman</a>, <a href="/search/astro-ph?searchtype=author&query=Dastidar%2C+R">Raya Dastidar</a>, <a href="/search/astro-ph?searchtype=author&query=Singh%2C+A">Avinash Singh</a>, <a href="/search/astro-ph?searchtype=author&query=Ackley%2C+K">Kendall Ackley</a>, <a href="/search/astro-ph?searchtype=author&query=Pursiainen%2C+M">Miika Pursiainen</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2403.18076v1-abstract-short" style="display: inline;"> We present the semi-analytical light curve modelling of 13 supernovae associated with gamma-ray bursts (GRB-SNe) along with two relativistic broad-lined (Ic-BL) SNe without GRBs association (SNe 2009bb and 2012ap), considering millisecond magnetars as central-engine-based power sources for these events. The bolometric light curves of all 15 SNe in our sample are well-regenerated utilising a… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2403.18076v1-abstract-full').style.display = 'inline'; document.getElementById('2403.18076v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2403.18076v1-abstract-full" style="display: none;"> We present the semi-analytical light curve modelling of 13 supernovae associated with gamma-ray bursts (GRB-SNe) along with two relativistic broad-lined (Ic-BL) SNe without GRBs association (SNe 2009bb and 2012ap), considering millisecond magnetars as central-engine-based power sources for these events. The bolometric light curves of all 15 SNe in our sample are well-regenerated utilising a $蠂^2-$minimisation code, $\texttt{MINIM}$, and numerous parameters are constrained. The median values of ejecta mass ($M_{\textrm{ej}}$), magnetar's initial spin period ($P_\textrm{i}$) and magnetic field ($B$) for GRB-SNe are determined to be $\approx$ 5.2 M$_\odot$, 20.5 ms and 20.1 $\times$ 10$^{14}$ G, respectively. We leverage machine learning (ML) algorithms to comprehensively compare the 3-dimensional parameter space encompassing $M_{\textrm{ej}}$, $P_\textrm{i}$, and $B$ for GRB-SNe determined herein to those of H-deficient superluminous SNe (SLSNe-I), fast blue optical transients (FBOTs), long GRBs (LGRBs), and short GRBs (SGRBs) obtained from the literature. The application of unsupervised ML clustering algorithms on the parameters $M_{\textrm{ej}}$, $P_\textrm{i}$, and $B$ for GRB-SNe, SLSNe-I, and FBOTs yields a classification accuracy of $\sim$95%. Extending these methods to classify GRB-SNe, SLSNe-I, LGRBs, and SGRBs based on $P_\textrm{i}$ and $B$ values results in an accuracy of $\sim$84%. Our investigations show that GRB-SNe and relativistic Ic-BL SNe presented in this study occupy different parameter spaces for $M_{\textrm{ej}}$, $P_\textrm{i}$, and $B$ than those of SLSNe-I, FBOTs, LGRBs and SGRBs. This indicates that magnetars with different $P_\textrm{i}$ and $B$ can give birth to distinct types of transients. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2403.18076v1-abstract-full').style.display = 'none'; document.getElementById('2403.18076v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 26 March, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> March 2024. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">13 pages, 7 figures, and 3 tables (including appendix). 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/2310.15967">arXiv:2310.15967</a> <span> [<a href="https://arxiv.org/pdf/2310.15967">pdf</a>, <a href="https://arxiv.org/format/2310.15967">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Astrophysics of Galaxies">astro-ph.GA</span> </div> </div> <p class="title is-5 mathjax"> Comparing emission- and absorption-based gas-phase metallicities in GRB host galaxies at $z=2-4$ using JWST </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Schady%2C+P">P. Schady</a>, <a href="/search/astro-ph?searchtype=author&query=Yates%2C+R+M">R. M. Yates</a>, <a href="/search/astro-ph?searchtype=author&query=Christensen%2C+L">L. Christensen</a>, <a href="/search/astro-ph?searchtype=author&query=De+Cia%2C+A">A. De Cia</a>, <a href="/search/astro-ph?searchtype=author&query=Rossi%2C+A">A. Rossi</a>, <a href="/search/astro-ph?searchtype=author&query=D%27Elia%2C+V">V. D'Elia</a>, <a href="/search/astro-ph?searchtype=author&query=Heintz%2C+K+E">K. E. Heintz</a>, <a href="/search/astro-ph?searchtype=author&query=Jakobsson%2C+P">P. Jakobsson</a>, <a href="/search/astro-ph?searchtype=author&query=Laskar%2C+T">T. Laskar</a>, <a href="/search/astro-ph?searchtype=author&query=Levan%2C+A">A. Levan</a>, <a href="/search/astro-ph?searchtype=author&query=Salvaterra%2C+R">R. Salvaterra</a>, <a href="/search/astro-ph?searchtype=author&query=Starling%2C+R+L+C">R. L. C. Starling</a>, <a href="/search/astro-ph?searchtype=author&query=Tanvir%2C+N+R">N. R Tanvir</a>, <a href="/search/astro-ph?searchtype=author&query=Th%C3%B6ne%2C+C+C">C. C. Th枚ne</a>, <a href="/search/astro-ph?searchtype=author&query=Vergani%2C+S">S. Vergani</a>, <a href="/search/astro-ph?searchtype=author&query=Wiersema%2C+K">K. Wiersema</a>, <a href="/search/astro-ph?searchtype=author&query=Arabsalmani%2C+M+.">M . Arabsalmani</a>, <a href="/search/astro-ph?searchtype=author&query=Chen%2C+H+-">H. -W. Chen</a>, <a href="/search/astro-ph?searchtype=author&query=De+Pasquale%2C+M">M. De Pasquale</a>, <a href="/search/astro-ph?searchtype=author&query=Fruchter%2C+A">A. Fruchter</a>, <a href="/search/astro-ph?searchtype=author&query=Fynbo%2C+J+P+U">J. P. U. Fynbo</a>, <a href="/search/astro-ph?searchtype=author&query=Garc%C3%ADa-Benito%2C+R">R. Garc铆a-Benito</a>, <a href="/search/astro-ph?searchtype=author&query=Gompertz%2C+B">B. Gompertz</a>, <a href="/search/astro-ph?searchtype=author&query=Hartmann%2C+D">D. Hartmann</a>, <a href="/search/astro-ph?searchtype=author&query=Kouveliotou%2C+C">C. Kouveliotou</a> , et al. (12 additional authors not shown) </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2310.15967v3-abstract-short" style="display: inline;"> Much of what is known of the chemical composition of the universe is based on emission line spectra from star forming galaxies. Emission-based inferences are, nevertheless, model-dependent and they are dominated by light from luminous star forming regions. An alternative and sensitive probe of the metallicity of galaxies is through absorption lines imprinted on the luminous afterglow spectra of lo… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2310.15967v3-abstract-full').style.display = 'inline'; document.getElementById('2310.15967v3-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2310.15967v3-abstract-full" style="display: none;"> Much of what is known of the chemical composition of the universe is based on emission line spectra from star forming galaxies. Emission-based inferences are, nevertheless, model-dependent and they are dominated by light from luminous star forming regions. An alternative and sensitive probe of the metallicity of galaxies is through absorption lines imprinted on the luminous afterglow spectra of long gamma ray bursts (GRBs) from neutral material within their host galaxy. We present results from a JWST/NIRSpec programme to investigate for the first time the relation between the metallicity of neutral gas probed in absorption by GRB afterglows and the metallicity of the star forming regions for the same host galaxy sample. Using an initial sample of eight GRB host galaxies at z=2.1-4.7, we find a tight relation between absorption and emission line metallicities when using the recently proposed $\hat{R}$ metallicity diagnostic (+/-0.2dex). This agreement implies a relatively chemically-homogeneous multi-phase interstellar medium, and indicates that absorption and emission line probes can be directly compared. However, the relation is less clear when using other diagnostics, such as R23 and R3. We also find possible evidence of an elevated N/O ratio in the host galaxy of GRB090323 at z=3.58, consistent with what has been seen in other $z>4$ galaxies. Ultimate confirmation of an enhanced N/O ratio and of the relation between absorption and emission line metallicities will require a more direct determination of the emission line metallicity via the detection of temperature-sensitive auroral lines in our GRB host galaxy sample. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2310.15967v3-abstract-full').style.display = 'none'; document.getElementById('2310.15967v3-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, 2024; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 24 October, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> October 2023. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">Accepted for publication in MNRAS; 24 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/2309.08493">arXiv:2309.08493</a> <span> [<a href="https://arxiv.org/pdf/2309.08493">pdf</a>, <a href="https://arxiv.org/format/2309.08493">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"> Evidence for a luminosity-decay correlation in GRB GeV light curves </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Hinds%2C+K+R">K. R. Hinds</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=Nicholl%2C+M">M. Nicholl</a>, <a href="/search/astro-ph?searchtype=author&query=Patel%2C+J">J. Patel</a>, <a href="/search/astro-ph?searchtype=author&query=Omodei%2C+N">N. Omodei</a>, <a href="/search/astro-ph?searchtype=author&query=Gompertz%2C+B">B. Gompertz</a>, <a href="/search/astro-ph?searchtype=author&query=Racusin%2C+J+L">J. L. Racusin</a>, <a href="/search/astro-ph?searchtype=author&query=Ryan%2C+G">G. Ryan</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2309.08493v1-abstract-short" style="display: inline;"> Correlations between intrinsic properties of gamma-ray burst (GRB) light curves provide clues to the nature of the central engine, the jet, and a possible means to standardise GRBs for cosmological use. Here we report on the discovery of a correlation between the intrinsic early time luminosity, $L_{G,\rm 10s}$, measured at rest frame 10s, and the average decay rate measured from rest frame 10s on… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2309.08493v1-abstract-full').style.display = 'inline'; document.getElementById('2309.08493v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2309.08493v1-abstract-full" style="display: none;"> Correlations between intrinsic properties of gamma-ray burst (GRB) light curves provide clues to the nature of the central engine, the jet, and a possible means to standardise GRBs for cosmological use. Here we report on the discovery of a correlation between the intrinsic early time luminosity, $L_{G,\rm 10s}$, measured at rest frame 10s, and the average decay rate measured from rest frame 10s onward, $伪_{G,\rm avg>10s}$, in a sample of 13 Fermi Large Array Telescope (LAT) long GRB light curves. We note that our selection criteria, in particular the requirement for a redshift to construct luminosity light curves, naturally limits our sample to energetic GRBs. A Spearman's rank correlation gives a coefficient of -0.74, corresponding to a confidence level of 99.6%, indicating that brighter afterglows decay faster than less luminous ones. Assuming a linear relation with $\log(L_{G,\rm 10s})$, we find $伪_{G,\rm avg>10s} = -0.31_{-0.09}^{+0.12}\log(L_{G,\rm 10s}) + 14.43_{-5.97}^{+4.55}$. The slope of -0.31 is consistent at $1蟽$ with previously identified correlations in the optical/UV and X-ray light curves. We speculate that differences in the rate at which energy is released by the central engine or differences in observer viewing angle may be responsible for the correlation. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2309.08493v1-abstract-full').style.display = 'none'; document.getElementById('2309.08493v1-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 September, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> September 2023. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">8 pages, 4 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/2309.03000">arXiv:2309.03000</a> <span> [<a href="https://arxiv.org/pdf/2309.03000">pdf</a>, <a href="https://arxiv.org/format/2309.03000">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="High Energy Astrophysical Phenomena">astro-ph.HE</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1051/0004-6361/202347113">10.1051/0004-6361/202347113 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> A search for the afterglows, kilonovae, and host galaxies of two short GRBs: GRB 211106A and GRB 211227A </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Ferro%2C+M">M. Ferro</a>, <a href="/search/astro-ph?searchtype=author&query=Brivio%2C+R">R. Brivio</a>, <a href="/search/astro-ph?searchtype=author&query=D%27Avanzo%2C+P">P. D'Avanzo</a>, <a href="/search/astro-ph?searchtype=author&query=Rossi%2C+A">A. Rossi</a>, <a href="/search/astro-ph?searchtype=author&query=Izzo%2C+L">L. Izzo</a>, <a href="/search/astro-ph?searchtype=author&query=Campana%2C+S">S. Campana</a>, <a href="/search/astro-ph?searchtype=author&query=Christensen%2C+L">L. Christensen</a>, <a href="/search/astro-ph?searchtype=author&query=Dinatolo%2C+M">M. Dinatolo</a>, <a href="/search/astro-ph?searchtype=author&query=Hussein%2C+S">S. Hussein</a>, <a href="/search/astro-ph?searchtype=author&query=Levan%2C+A+J">A. J. Levan</a>, <a href="/search/astro-ph?searchtype=author&query=Melandri%2C+A">A. Melandri</a>, <a href="/search/astro-ph?searchtype=author&query=Bernardini%2C+M+G">M. G. Bernardini</a>, <a href="/search/astro-ph?searchtype=author&query=Covino%2C+S">S. Covino</a>, <a href="/search/astro-ph?searchtype=author&query=D%27Elia%2C+V">V. D'Elia</a>, <a href="/search/astro-ph?searchtype=author&query=Della+Valle%2C+M">M. Della Valle</a>, <a href="/search/astro-ph?searchtype=author&query=De+Pasquale%2C+M">M. De Pasquale</a>, <a href="/search/astro-ph?searchtype=author&query=Gompertz%2C+B+P">B. P. Gompertz</a>, <a href="/search/astro-ph?searchtype=author&query=Hartmann%2C+D">D. Hartmann</a>, <a href="/search/astro-ph?searchtype=author&query=Heintz%2C+K+E">K. E. Heintz</a>, <a href="/search/astro-ph?searchtype=author&query=Jakobsson%2C+P">P. Jakobsson</a>, <a href="/search/astro-ph?searchtype=author&query=Kouveliotou%2C+C">C. Kouveliotou</a>, <a href="/search/astro-ph?searchtype=author&query=Malesani%2C+D+B">D. B. Malesani</a>, <a href="/search/astro-ph?searchtype=author&query=Martin-Carrillo%2C+A">A. Martin-Carrillo</a>, <a href="/search/astro-ph?searchtype=author&query=Nava%2C+L">L. Nava</a>, <a href="/search/astro-ph?searchtype=author&query=Guelbenzu%2C+A+N">A. Nicuesa Guelbenzu</a> , et al. (8 additional authors not shown) </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2309.03000v1-abstract-short" style="display: inline;"> Context: GRB 211106A and GRB 211227A are recent gamma-ray bursts (GRBs) with initial X-ray positions suggesting associations with nearby galaxies (z < 0.7). Their prompt emission characteristics indicate GRB 211106A is a short-duration GRB and GRB 211227A is a short GRB with extended emission, likely originating from compact binary mergers. However, classifying solely based on prompt emission can… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2309.03000v1-abstract-full').style.display = 'inline'; document.getElementById('2309.03000v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2309.03000v1-abstract-full" style="display: none;"> Context: GRB 211106A and GRB 211227A are recent gamma-ray bursts (GRBs) with initial X-ray positions suggesting associations with nearby galaxies (z < 0.7). Their prompt emission characteristics indicate GRB 211106A is a short-duration GRB and GRB 211227A is a short GRB with extended emission, likely originating from compact binary mergers. However, classifying solely based on prompt emission can be misleading. Aims: These short GRBs in the local Universe offer opportunities to search for associated kilonova (KN) emission and study host galaxy properties in detail. Methods: We conducted deep optical and NIR follow-up using ESO-VLT FORS2, HAWK-I, and MUSE for GRB 211106A, and ESO-VLT FORS2 and X-Shooter for GRB 211227A, starting shortly after the X-ray afterglow detection. We performed photometric analysis to look for afterglow and KN emissions associated with the bursts, along with host galaxy imaging and spectroscopy. Optical/NIR results were compared with Swift X-Ray Telescope (XRT) and other high-energy data. Results: For both GRBs we placed deep limits to the optical/NIR afterglow and KN emission. Host galaxies were identified: GRB 211106A at photometric z = 0.64 and GRB 211227A at spectroscopic z = 0.228. Host galaxy properties aligned with typical short GRB hosts. We also compared the properties of the bursts with the S-BAT4 sample to further examined the nature of these events. Conclusions: Study of prompt and afterglow phases, along with host galaxy analysis, confirms GRB 211106A as a short GRB and GRB 211227A as a short GRB with extended emission. The absence of optical/NIR counterparts is likely due to local extinction for GRB 211106A and a faint kilonova for GRB 211227A. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2309.03000v1-abstract-full').style.display = 'none'; document.getElementById('2309.03000v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 6 September, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> September 2023. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">Accepted to A&A on 08 August 2023, 21 pages, 24 figures</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> A&A 678, A142 (2023) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2307.02556">arXiv:2307.02556</a> <span> [<a href="https://arxiv.org/pdf/2307.02556">pdf</a>, <a href="https://arxiv.org/format/2307.02556">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="High Energy Astrophysical Phenomena">astro-ph.HE</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Cosmology and Nongalactic Astrophysics">astro-ph.CO</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> </div> </div> <p class="title is-5 mathjax"> AT2022aedm and a new class of luminous, fast-cooling transients in elliptical galaxies </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Nicholl%2C+M">M. Nicholl</a>, <a href="/search/astro-ph?searchtype=author&query=Srivastav%2C+S">S. Srivastav</a>, <a href="/search/astro-ph?searchtype=author&query=Fulton%2C+M+D">M. D. Fulton</a>, <a href="/search/astro-ph?searchtype=author&query=Gomez%2C+S">S. Gomez</a>, <a href="/search/astro-ph?searchtype=author&query=Huber%2C+M+E">M. E. Huber</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=Ramsden%2C+P">P. Ramsden</a>, <a href="/search/astro-ph?searchtype=author&query=Rhodes%2C+L">L. Rhodes</a>, <a href="/search/astro-ph?searchtype=author&query=Smartt%2C+S+J">S. J. Smartt</a>, <a href="/search/astro-ph?searchtype=author&query=Smith%2C+K+W">K. W. Smith</a>, <a href="/search/astro-ph?searchtype=author&query=Aamer%2C+A">A. Aamer</a>, <a href="/search/astro-ph?searchtype=author&query=Anderson%2C+J+P">J. P. Anderson</a>, <a href="/search/astro-ph?searchtype=author&query=Bauer%2C+F+E">F. E. Bauer</a>, <a href="/search/astro-ph?searchtype=author&query=Berger%2C+E">E. Berger</a>, <a href="/search/astro-ph?searchtype=author&query=de+Boer%2C+T">T. de Boer</a>, <a href="/search/astro-ph?searchtype=author&query=Chambers%2C+K+C">K. C. Chambers</a>, <a href="/search/astro-ph?searchtype=author&query=Charalampopoulos%2C+P">P. Charalampopoulos</a>, <a href="/search/astro-ph?searchtype=author&query=Chen%2C+T+-">T. -W. Chen</a>, <a href="/search/astro-ph?searchtype=author&query=Fender%2C+R+P">R. P. Fender</a>, <a href="/search/astro-ph?searchtype=author&query=Fraser%2C+M">M. Fraser</a>, <a href="/search/astro-ph?searchtype=author&query=Gao%2C+H">H. Gao</a>, <a href="/search/astro-ph?searchtype=author&query=Green%2C+D+A">D. A. Green</a>, <a href="/search/astro-ph?searchtype=author&query=Galbany%2C+L">L. Galbany</a>, <a href="/search/astro-ph?searchtype=author&query=Gompertz%2C+B+P">B. P. Gompertz</a>, <a href="/search/astro-ph?searchtype=author&query=Gromadzki%2C+M">M. Gromadzki</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="2307.02556v2-abstract-short" style="display: inline;"> We present the discovery and extensive follow-up of a remarkable fast-evolving optical transient, AT2022aedm, detected by the Asteroid Terrestrial impact Last Alert Survey (ATLAS). AT2022aedm exhibited a rise time of $9\pm1$ days in the ATLAS $o$-band, reaching a luminous peak with $M_g\approx-22$ mag. It faded by 2 magnitudes in $g$-band during the next 15 days. These timescales are consistent wi… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2307.02556v2-abstract-full').style.display = 'inline'; document.getElementById('2307.02556v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2307.02556v2-abstract-full" style="display: none;"> We present the discovery and extensive follow-up of a remarkable fast-evolving optical transient, AT2022aedm, detected by the Asteroid Terrestrial impact Last Alert Survey (ATLAS). AT2022aedm exhibited a rise time of $9\pm1$ days in the ATLAS $o$-band, reaching a luminous peak with $M_g\approx-22$ mag. It faded by 2 magnitudes in $g$-band during the next 15 days. These timescales are consistent with other rapidly evolving transients, though the luminosity is extreme. Most surprisingly, the host galaxy is a massive elliptical with negligible current star formation. X-ray and radio observations rule out a relativistic AT2018cow-like explosion. A spectrum in the first few days after explosion showed short-lived He II emission resembling young core-collapse supernovae, but obvious broad supernova features never developed; later spectra showed only a fast-cooling continuum and narrow, blue-shifted absorption lines, possibly arising in a wind with $v\approx2700$ km s$^{-1}$. We identify two further transients in the literature (Dougie in particular, as well as AT2020bot) that share similarities in their luminosities, timescales, colour evolution and largely featureless spectra, and propose that these may constitute a new class of transients: luminous fast-coolers (LFCs). All three events occurred in passive galaxies at offsets of $\sim4-10$ kpc from the nucleus, posing a challenge for progenitor models involving massive stars or massive black holes. The light curves and spectra appear to be consistent with shock breakout emission, though usually this mechanism is associated with core-collapse supernovae. The encounter of a star with a stellar mass black hole may provide a promising alternative explanation. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2307.02556v2-abstract-full').style.display = 'none'; document.getElementById('2307.02556v2-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 21 August, 2023; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 5 July, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> July 2023. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">Accepted in ApJL</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2307.02487">arXiv:2307.02487</a> <span> [<a href="https://arxiv.org/pdf/2307.02487">pdf</a>, <a href="https://arxiv.org/format/2307.02487">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="High Energy Astrophysical Phenomena">astro-ph.HE</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1093/mnras/stad3776">10.1093/mnras/stad3776 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> A Precursor Plateau and Pre-Maximum [O II] Emission in the Superluminous SN2019szu: A Pulsational Pair-Instability Candidate </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Aamer%2C+A">Aysha Aamer</a>, <a href="/search/astro-ph?searchtype=author&query=Nicholl%2C+M">Matt Nicholl</a>, <a href="/search/astro-ph?searchtype=author&query=Jerkstrand%2C+A">Anders Jerkstrand</a>, <a href="/search/astro-ph?searchtype=author&query=Gomez%2C+S">Sebastian Gomez</a>, <a href="/search/astro-ph?searchtype=author&query=Oates%2C+S+R">Samantha R. Oates</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=Srivastav%2C+S">Shubham Srivastav</a>, <a href="/search/astro-ph?searchtype=author&query=Leloudas%2C+G">Giorgos Leloudas</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=Berger%2C+E">Edo Berger</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=Chambers%2C+K">Kenneth Chambers</a>, <a href="/search/astro-ph?searchtype=author&query=Chen%2C+T">Ting-Wan Chen</a>, <a href="/search/astro-ph?searchtype=author&query=Galbany%2C+L">Llu铆s Galbany</a>, <a href="/search/astro-ph?searchtype=author&query=Gao%2C+H">Hua Gao</a>, <a href="/search/astro-ph?searchtype=author&query=Gompertz%2C+B+P">Benjamin P. Gompertz</a>, <a href="/search/astro-ph?searchtype=author&query=Gonz%C3%A1lez-Ba%C3%B1uelos%2C+M">Maider Gonz谩lez-Ba帽uelos</a>, <a href="/search/astro-ph?searchtype=author&query=Gromadzki%2C+M">Mariusz Gromadzki</a>, <a href="/search/astro-ph?searchtype=author&query=Guti%C3%A9rrez%2C+C+P">Claudia P. Guti茅rrez</a>, <a href="/search/astro-ph?searchtype=author&query=Inserra%2C+C">Cosimo Inserra</a>, <a href="/search/astro-ph?searchtype=author&query=Lowe%2C+T+B">Thomas B. Lowe</a>, <a href="/search/astro-ph?searchtype=author&query=Magnier%2C+E+A">Eugene A. Magnier</a>, <a href="/search/astro-ph?searchtype=author&query=Mazzali%2C+P+A">Paolo A. Mazzali</a>, <a href="/search/astro-ph?searchtype=author&query=Moore%2C+T">Thomas Moore</a>, <a href="/search/astro-ph?searchtype=author&query=M%C3%BCller-Bravo%2C+T+E">Tom谩s E. M眉ller-Bravo</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="2307.02487v2-abstract-short" style="display: inline;"> We present a detailed study on SN2019szu, a Type I superluminous supernova at $z=0.213$, that displayed unique photometric and spectroscopic properties. Pan-STARRS and ZTF forced photometry shows a pre-explosion plateau lasting $\sim$ 40 days. Unlike other SLSNe that show decreasing photospheric temperatures with time, the optical colours show an apparent temperature increase from $\sim$15000 K to… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2307.02487v2-abstract-full').style.display = 'inline'; document.getElementById('2307.02487v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2307.02487v2-abstract-full" style="display: none;"> We present a detailed study on SN2019szu, a Type I superluminous supernova at $z=0.213$, that displayed unique photometric and spectroscopic properties. Pan-STARRS and ZTF forced photometry shows a pre-explosion plateau lasting $\sim$ 40 days. Unlike other SLSNe that show decreasing photospheric temperatures with time, the optical colours show an apparent temperature increase from $\sim$15000 K to $\sim$20000 K over the first 70 days, likely caused by an additional pseudo-continuum in the spectrum. Remarkably, the spectrum displays a forbidden emission line even during the rising phase of the light curve, inconsistent with an apparently compact photosphere. We show that this early feature is [O II] $位位$7320,7330. We also see evidence for [O III] $位位$4959, 5007, and [O III] $位$4363 further strengthening this line identification. Comparing with models for nebular emission, we find that the oxygen line fluxes and ratios can be reproduced with $\sim$0.25 M$_{\odot}$ of oxygen rich material with a density of $\sim10^{-15} \rm{g cm}^{-3}$. The low density suggests a circumstellar origin, but the early onset of the emission lines requires that this material was ejected within the final months before the terminal explosion, consistent with the timing of the precursor plateau. Interaction with denser material closer to the explosion likely produced the pseudo-continuum bluewards of $\sim$5500 脜. We suggest that this event is one of the best candidates to date for a pulsational pair-instability ejection, with early pulses providing the low density material needed for the forbidden emission line, and collisions between the final shells of ejected material producing the pre-explosion plateau. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2307.02487v2-abstract-full').style.display = 'none'; document.getElementById('2307.02487v2-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 17 January, 2024; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 5 July, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> July 2023. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">Accepted for publication in MNRAS</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Volume 527, (2024), Pages 11970-11995 </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2307.02098">arXiv:2307.02098</a> <span> [<a href="https://arxiv.org/pdf/2307.02098">pdf</a>, <a href="https://arxiv.org/format/2307.02098">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="High Energy Astrophysical Phenomena">astro-ph.HE</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Cosmology and Nongalactic Astrophysics">astro-ph.CO</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1038/s41586-023-06759-1">10.1038/s41586-023-06759-1 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> JWST detection of heavy neutron capture elements in a compact object merger </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Levan%2C+A">A. Levan</a>, <a href="/search/astro-ph?searchtype=author&query=Gompertz%2C+B+P">B. P. Gompertz</a>, <a href="/search/astro-ph?searchtype=author&query=Salafia%2C+O+S">O. S. Salafia</a>, <a href="/search/astro-ph?searchtype=author&query=Bulla%2C+M">M. Bulla</a>, <a href="/search/astro-ph?searchtype=author&query=Burns%2C+E">E. Burns</a>, <a href="/search/astro-ph?searchtype=author&query=Hotokezaka%2C+K">K. Hotokezaka</a>, <a href="/search/astro-ph?searchtype=author&query=Izzo%2C+L">L. Izzo</a>, <a href="/search/astro-ph?searchtype=author&query=Lamb%2C+G+P">G. P. Lamb</a>, <a href="/search/astro-ph?searchtype=author&query=Malesani%2C+D+B">D. B. Malesani</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=Ravasio%2C+M+E">M. E. Ravasio</a>, <a href="/search/astro-ph?searchtype=author&query=Escorial%2C+A+R">A. Rouco Escorial</a>, <a href="/search/astro-ph?searchtype=author&query=Schneider%2C+B">B. Schneider</a>, <a href="/search/astro-ph?searchtype=author&query=Sarin%2C+N">N. Sarin</a>, <a href="/search/astro-ph?searchtype=author&query=Schulze%2C+S">S. Schulze</a>, <a href="/search/astro-ph?searchtype=author&query=Tanvir%2C+N+R">N. R. Tanvir</a>, <a href="/search/astro-ph?searchtype=author&query=Ackley%2C+K">K. Ackley</a>, <a href="/search/astro-ph?searchtype=author&query=Anderson%2C+G">G. Anderson</a>, <a href="/search/astro-ph?searchtype=author&query=Brammer%2C+G+B">G. B. Brammer</a>, <a href="/search/astro-ph?searchtype=author&query=Christensen%2C+L">L. Christensen</a>, <a href="/search/astro-ph?searchtype=author&query=Dhillon%2C+V+S">V. S. Dhillon</a>, <a href="/search/astro-ph?searchtype=author&query=Evans%2C+P+A">P. A. Evans</a>, <a href="/search/astro-ph?searchtype=author&query=Fausnaugh%2C+M">M. Fausnaugh</a>, <a href="/search/astro-ph?searchtype=author&query=Fong%2C+W+-">W. -F. Fong</a>, <a href="/search/astro-ph?searchtype=author&query=Fruchter%2C+A+S">A. S. Fruchter</a> , et al. (58 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="2307.02098v1-abstract-short" style="display: inline;"> The mergers of binary compact objects such as neutron stars and black holes are of central interest to several areas of astrophysics, including as the progenitors of gamma-ray bursts (GRBs), sources of high-frequency gravitational waves and likely production sites for heavy element nucleosynthesis via rapid neutron capture (the r-process). These heavy elements include some of great geophysical, bi… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2307.02098v1-abstract-full').style.display = 'inline'; document.getElementById('2307.02098v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2307.02098v1-abstract-full" style="display: none;"> The mergers of binary compact objects such as neutron stars and black holes are of central interest to several areas of astrophysics, including as the progenitors of gamma-ray bursts (GRBs), sources of high-frequency gravitational waves and likely production sites for heavy element nucleosynthesis via rapid neutron capture (the r-process). These heavy elements include some of great geophysical, biological and cultural importance, such as thorium, iodine and gold. Here we present observations of the exceptionally bright gamma-ray burst GRB 230307A. We show that GRB 230307A belongs to the class of long-duration gamma-ray bursts associated with compact object mergers, and contains a kilonova similar to AT2017gfo, associated with the gravitational-wave merger GW170817. We obtained James Webb Space Telescope mid-infrared (mid-IR) imaging and spectroscopy 29 and 61 days after the burst. The spectroscopy shows an emission line at 2.15 microns which we interpret as tellurium (atomic mass A=130), and a very red source, emitting most of its light in the mid-IR due to the production of lanthanides. These observations demonstrate that nucleosynthesis in GRBs can create r-process elements across a broad atomic mass range and play a central role in heavy element nucleosynthesis across the Universe. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2307.02098v1-abstract-full').style.display = 'none'; document.getElementById('2307.02098v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 5 July, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> July 2023. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">Submitted. Comments welcome! Nature (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/2307.01771">arXiv:2307.01771</a> <span> [<a href="https://arxiv.org/pdf/2307.01771">pdf</a>, <a href="https://arxiv.org/format/2307.01771">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="High Energy Astrophysical Phenomena">astro-ph.HE</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Astrophysics of Galaxies">astro-ph.GA</span> </div> </div> <p class="title is-5 mathjax"> AT2023fhn (the Finch): a Luminous Fast Blue Optical Transient at a large offset from its host galaxy </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Chrimes%2C+A+A">A. A. Chrimes</a>, <a href="/search/astro-ph?searchtype=author&query=Jonker%2C+P+G">P. G. Jonker</a>, <a href="/search/astro-ph?searchtype=author&query=Levan%2C+A+J">A. J. Levan</a>, <a href="/search/astro-ph?searchtype=author&query=Coppejans%2C+D+L">D. L. Coppejans</a>, <a href="/search/astro-ph?searchtype=author&query=Gaspari%2C+N">N. Gaspari</a>, <a href="/search/astro-ph?searchtype=author&query=Gompertz%2C+B+P">B. P. Gompertz</a>, <a href="/search/astro-ph?searchtype=author&query=Groot%2C+P+J">P. J. Groot</a>, <a href="/search/astro-ph?searchtype=author&query=Malesani%2C+D+B">D. B. Malesani</a>, <a href="/search/astro-ph?searchtype=author&query=Mummery%2C+A">A. Mummery</a>, <a href="/search/astro-ph?searchtype=author&query=Stanway%2C+E+R">E. R. Stanway</a>, <a href="/search/astro-ph?searchtype=author&query=Wiersema%2C+K">K. Wiersema</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2307.01771v2-abstract-short" style="display: inline;"> Luminous Fast Blue Optical Transients (LFBOTs) - the prototypical example being AT2018cow - are a rare class of events whose origins are poorly understood. They are characterised by rapid evolution, featureless blue spectra at early times, and luminous X-ray and radio emission. LFBOTs thus far have been found exclusively at small projected offsets from star-forming host galaxies. We present Hubble… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2307.01771v2-abstract-full').style.display = 'inline'; document.getElementById('2307.01771v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2307.01771v2-abstract-full" style="display: none;"> Luminous Fast Blue Optical Transients (LFBOTs) - the prototypical example being AT2018cow - are a rare class of events whose origins are poorly understood. They are characterised by rapid evolution, featureless blue spectra at early times, and luminous X-ray and radio emission. LFBOTs thus far have been found exclusively at small projected offsets from star-forming host galaxies. We present Hubble Space Telescope, Gemini, Chandra and Very Large Array observations of a new LFBOT, AT2023fhn. The Hubble Space Telescope data reveal a large offset (greater than 3.5 half-light radii) from the two closest galaxies, both at a redshift of 0.24. The location of AT2023fhn is in stark contrast with previous events, and demonstrates that LFBOTs can occur in a range of galactic environments. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2307.01771v2-abstract-full').style.display = 'none'; document.getElementById('2307.01771v2-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 3 October, 2023; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 4 July, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> July 2023. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">Accepted for publication in MNRASL. 7 pages, 4 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/2305.14491">arXiv:2305.14491</a> <span> [<a href="https://arxiv.org/pdf/2305.14491">pdf</a>, <a href="https://arxiv.org/ps/2305.14491">ps</a>, <a href="https://arxiv.org/format/2305.14491">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/stad1703">10.1093/mnras/stad1703 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> GRB 201015A and the nature of low-luminosity soft gamma-ray bursts </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Patel%2C+M">M. Patel</a>, <a href="/search/astro-ph?searchtype=author&query=Gompertz%2C+B+P">B. P. Gompertz</a>, <a href="/search/astro-ph?searchtype=author&query=O%27Brien%2C+P+T">P. T. O'Brien</a>, <a href="/search/astro-ph?searchtype=author&query=Lamb%2C+G+P">G. P. Lamb</a>, <a href="/search/astro-ph?searchtype=author&query=Starling%2C+R+L+C">R. L. C. Starling</a>, <a href="/search/astro-ph?searchtype=author&query=Evans%2C+P+A">P. A Evans</a>, <a href="/search/astro-ph?searchtype=author&query=Amati%2C+L">L. Amati</a>, <a href="/search/astro-ph?searchtype=author&query=Levan%2C+A+J">A. J. Levan</a>, <a href="/search/astro-ph?searchtype=author&query=Nicholl%2C+M">M. Nicholl</a>, <a href="/search/astro-ph?searchtype=author&query=Lyman%2C+J">J. Lyman</a>, <a href="/search/astro-ph?searchtype=author&query=Ackley%2C+K">K. Ackley</a>, <a href="/search/astro-ph?searchtype=author&query=Dyer%2C+M+J">M. J. Dyer</a>, <a href="/search/astro-ph?searchtype=author&query=Ulaczyk%2C+K">K. Ulaczyk</a>, <a href="/search/astro-ph?searchtype=author&query=Steeghs%2C+D">D. Steeghs</a>, <a href="/search/astro-ph?searchtype=author&query=Galloway%2C+D+K">D. K. Galloway</a>, <a href="/search/astro-ph?searchtype=author&query=Dhillon%2C+V+S">V. S. Dhillon</a>, <a href="/search/astro-ph?searchtype=author&query=Ramsay%2C+G">G. Ramsay</a>, <a href="/search/astro-ph?searchtype=author&query=Noysena%2C+K">K. Noysena</a>, <a href="/search/astro-ph?searchtype=author&query=Kotak%2C+R">R. Kotak</a>, <a href="/search/astro-ph?searchtype=author&query=Breton%2C+R+P">R. P. Breton</a>, <a href="/search/astro-ph?searchtype=author&query=Nuttall%2C+L+K">L. K. Nuttall</a>, <a href="/search/astro-ph?searchtype=author&query=Palle%2C+E">E. Palle</a>, <a href="/search/astro-ph?searchtype=author&query=Pollacco%2C+D">D. Pollacco</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="2305.14491v1-abstract-short" style="display: inline;"> GRB 201015A is a peculiarly low luminosity, spectrally soft gamma-ray burst (GRB), with $T_{\rm 90} = 9.8 \pm 3.5$ s (time interval of detection of 90\% of photons from the GRB), and an associated supernova (likely to be type Ic or Ic-BL). GRB 201015A has an isotropic energy $E_{纬,\rm iso} = 1.75 ^{+0.60} _{-0.53} \times 10^{50}$ erg, and photon index $螕= 3.00 ^{+0.50} _{-0.42}$ (15-150 keV). It f… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2305.14491v1-abstract-full').style.display = 'inline'; document.getElementById('2305.14491v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2305.14491v1-abstract-full" style="display: none;"> GRB 201015A is a peculiarly low luminosity, spectrally soft gamma-ray burst (GRB), with $T_{\rm 90} = 9.8 \pm 3.5$ s (time interval of detection of 90\% of photons from the GRB), and an associated supernova (likely to be type Ic or Ic-BL). GRB 201015A has an isotropic energy $E_{纬,\rm iso} = 1.75 ^{+0.60} _{-0.53} \times 10^{50}$ erg, and photon index $螕= 3.00 ^{+0.50} _{-0.42}$ (15-150 keV). It follows the Amati relation, a correlation between $E_{纬,\rm iso}$ and spectral peak energy $E_{\rm p}$ followed by long GRBs. It appears exceptionally soft based on $螕$, the hardness ratio of HR = $0.47 \pm 0.24$, and low-$E_{\rm p}$, so we have compared it to other GRBs sharing these properties. These events can be explained by shock breakout, poorly collimated jets, and off-axis viewing. Follow-up observations of the afterglow taken in the X-ray, optical, and radio, reveal a surprisingly late flattening in the X-ray from $t = (2.61 \pm 1.27)\times 10^4$ s to $t = 1.67 ^{+1.14} _{-0.65} \times 10^6$ s. We fit the data to closure relations describing the synchrotron emission, finding the electron spectral index to be $p = 2.42 ^{+0.44} _{-0.30}$, and evidence of late-time energy injection with coefficient $q = 0.24 ^{+0.24} _{-0.18}$. The jet half opening angle lower limit ($胃_{j} \ge 16^{\circ}$) is inferred from the non-detection of a jet break. The launch of SVOM and Einstein Probe in 2023, should enable detection of more low luminosity events like this, providing a fuller picture of the variety of GRBs. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2305.14491v1-abstract-full').style.display = 'none'; document.getElementById('2305.14491v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 23 May, 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">15 pages, 4 figures</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2305.07582">arXiv:2305.07582</a> <span> [<a href="https://arxiv.org/pdf/2305.07582">pdf</a>, <a href="https://arxiv.org/format/2305.07582">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"> A multi-messenger model for neutron star - black hole mergers </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Gompertz%2C+B+P">B. P. Gompertz</a>, <a href="/search/astro-ph?searchtype=author&query=Nicholl%2C+M">M. Nicholl</a>, <a href="/search/astro-ph?searchtype=author&query=Smith%2C+J+C">J. C. Smith</a>, <a href="/search/astro-ph?searchtype=author&query=Harisankar%2C+S">S. Harisankar</a>, <a href="/search/astro-ph?searchtype=author&query=Pratten%2C+G">G. Pratten</a>, <a href="/search/astro-ph?searchtype=author&query=Schmidt%2C+P">P. Schmidt</a>, <a href="/search/astro-ph?searchtype=author&query=Smith%2C+G+P">G. P. Smith</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="2305.07582v2-abstract-short" style="display: inline;"> We present a semi-analytic model for predicting kilonova light curves from the mergers of neutron stars with black holes (NSBH). The model is integrated into the MOSFiT platform, and can generate light curves from input binary properties and nuclear equation-of-state considerations, or incorporate measurements from gravitational wave (GW) detectors to perform multi-messenger parameter estimation.… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2305.07582v2-abstract-full').style.display = 'inline'; document.getElementById('2305.07582v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2305.07582v2-abstract-full" style="display: none;"> We present a semi-analytic model for predicting kilonova light curves from the mergers of neutron stars with black holes (NSBH). The model is integrated into the MOSFiT platform, and can generate light curves from input binary properties and nuclear equation-of-state considerations, or incorporate measurements from gravitational wave (GW) detectors to perform multi-messenger parameter estimation. The rapid framework enables the generation of NSBH kilonova distributions from binary populations, light curve predictions from GW data, and statistically meaningful comparisons with an equivalent BNS model in MOSFiT. We investigate a sample of kilonova candidates associated with cosmological short gamma-ray bursts, and demonstrate that they are broadly consistent with being driven by NSBH systems, though most have limited data. We also perform fits to the very well sampled GW170817, and show that the inability of an NSBH merger to produce lanthanide-poor ejecta results in a significant underestimate of the early (< 2 days) optical emission. Our model indicates that NSBH-driven kilonovae may peak up to a week after merger at optical wavelengths for some observer angles. This demonstrates the need for early coverage of emergent kilonovae in cases where the GW signal is either ambiguous or absent; they likely cannot be distinguished from BNS mergers by the light curves alone from ~2 days after the merger. We also discuss the detectability of our model kilonovae with the Vera C. Rubin Observatory's Legacy Survey of Space and Time (LSST). <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2305.07582v2-abstract-full').style.display = 'none'; document.getElementById('2305.07582v2-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 29 September, 2023; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 12 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">14 pages, 6 figures, 2 tables. Accepted for publication in MNRAS. This is the author's final submitted version. The model code is available through MOSFiT at https://github.com/guillochon/MOSFiT</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2303.12935">arXiv:2303.12935</a> <span> [<a href="https://arxiv.org/pdf/2303.12935">pdf</a>, <a href="https://arxiv.org/format/2303.12935">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="High Energy Astrophysical Phenomena">astro-ph.HE</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Cosmology and Nongalactic Astrophysics">astro-ph.CO</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> </div> <div 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/acd18c">10.3847/2041-8213/acd18c <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> GRB 191019A: a short gamma-ray burst in disguise from the disk of an active galactic nucleus </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Lazzati%2C+D">Davide Lazzati</a>, <a href="/search/astro-ph?searchtype=author&query=Perna%2C+R">Rosalba Perna</a>, <a href="/search/astro-ph?searchtype=author&query=Gompertz%2C+B">Benjamin Gompertz</a>, <a href="/search/astro-ph?searchtype=author&query=Levan%2C+A">Andrew Levan</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2303.12935v2-abstract-short" style="display: inline;"> Long and short gamma-ray bursts (GRBs), canonically separated at around 2 seconds duration, are associated with different progenitors: the collapse of a massive star and the merger of two compact objects, respectively. GRB 191019A was a long GRB ($T_{90}\sim64$ s). Despite the relatively small redshift z=0.248 and HST followup observations, an accompanying supernova was not detected. In addition,… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2303.12935v2-abstract-full').style.display = 'inline'; document.getElementById('2303.12935v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2303.12935v2-abstract-full" style="display: none;"> Long and short gamma-ray bursts (GRBs), canonically separated at around 2 seconds duration, are associated with different progenitors: the collapse of a massive star and the merger of two compact objects, respectively. GRB 191019A was a long GRB ($T_{90}\sim64$ s). Despite the relatively small redshift z=0.248 and HST followup observations, an accompanying supernova was not detected. In addition, the host galaxy did not have significant star formation activity. Here we propose that GRB 191019A was produced by a binary compact merger, whose prompt emission was stretched in time by the interaction with a dense external medium. This would be expected if the burst progenitor was located in the disk of an active galactic nucleus, as supported by the burst localization close to the center of its host galaxy. We show that the light curve of GRB 191019A can be well modeled by a burst of intrinsic duration t=1.1 s and of energy $E_{\rm{iso}}=10^{51}$ erg seen moderately off-axis, exploding in a medium of density $10^7-10^8$ cm$^{-3}$. The double-peaked light curve carries the telltale features predicted for GRBs in high-density media, where the first peak is produced by the photosphere, and the second by the overlap of reverse shocks that take place before the internal shocks could happen. This would make GRB 191019A the first confirmed stellar explosion from within an accretion disk, with important implications for the formation and evolution of stars in accretion flows and for gravitational waves source populations. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2303.12935v2-abstract-full').style.display = 'none'; document.getElementById('2303.12935v2-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 26 April, 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">6 pages, 2 figures. Accepted for publication in ApJL</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2303.12912">arXiv:2303.12912</a> <span> [<a href="https://arxiv.org/pdf/2303.12912">pdf</a>, <a href="https://arxiv.org/format/2303.12912">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/10.21203/rs.3.rs-2298504/v1">10.21203/rs.3.rs-2298504/v1 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> A long-duration gamma-ray burst of dynamical origin from the nucleus of an ancient galaxy </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Levan%2C+A+J">Andrew J. Levan</a>, <a href="/search/astro-ph?searchtype=author&query=Malesani%2C+D+B">Daniele B. Malesani</a>, <a href="/search/astro-ph?searchtype=author&query=Gompertz%2C+B+P">Benjamin P. Gompertz</a>, <a href="/search/astro-ph?searchtype=author&query=Nugent%2C+A+E">Anya E. Nugent</a>, <a href="/search/astro-ph?searchtype=author&query=Nicholl%2C+M">Matt Nicholl</a>, <a href="/search/astro-ph?searchtype=author&query=Oates%2C+S">Samantha Oates</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=Rastinejad%2C+J">Jillian Rastinejad</a>, <a href="/search/astro-ph?searchtype=author&query=Metzger%2C+B+D">Brian D. Metzger</a>, <a href="/search/astro-ph?searchtype=author&query=Schulze%2C+S">Steve Schulze</a>, <a href="/search/astro-ph?searchtype=author&query=Stanway%2C+E+R">Elizabeth R. Stanway</a>, <a href="/search/astro-ph?searchtype=author&query=Inkenhaag%2C+A">Anne Inkenhaag</a>, <a href="/search/astro-ph?searchtype=author&query=Zafar%2C+T">Tayyaba Zafar</a>, <a href="/search/astro-ph?searchtype=author&query=Fernandez%2C+J+F+A">J. Feliciano Agui Fernandez</a>, <a href="/search/astro-ph?searchtype=author&query=Chrimes%2C+A">Ashley Chrimes</a>, <a href="/search/astro-ph?searchtype=author&query=Bhirombhakdi%2C+K">Kornpob Bhirombhakdi</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=Fong%2C+W">Wen-fai Fong</a>, <a href="/search/astro-ph?searchtype=author&query=Fruchter%2C+A+S">Andrew S. Fruchter</a>, <a href="/search/astro-ph?searchtype=author&query=Fragione%2C+G">Giacomo Fragione</a>, <a href="/search/astro-ph?searchtype=author&query=Fynbo%2C+J+P+U">Johan P. U. Fynbo</a>, <a href="/search/astro-ph?searchtype=author&query=Gaspari%2C+N">Nicola Gaspari</a>, <a href="/search/astro-ph?searchtype=author&query=Heintz%2C+K+E">Kasper E. Heintz</a>, <a href="/search/astro-ph?searchtype=author&query=Hjorth%2C+J">Jens Hjorth</a>, <a href="/search/astro-ph?searchtype=author&query=Jakobsson%2C+P">Pall Jakobsson</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="2303.12912v1-abstract-short" style="display: inline;"> The majority of long duration ($>2$ s) gamma-ray bursts (GRBs) are believed to arise from the collapse of massive stars \cite{Hjorth+03}, with a small proportion created from the merger of compact objects. Most of these systems are likely formed via standard stellar evolution pathways. However, it has long been thought that a fraction of GRBs may instead be an outcome of dynamical interactions in… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2303.12912v1-abstract-full').style.display = 'inline'; document.getElementById('2303.12912v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2303.12912v1-abstract-full" style="display: none;"> The majority of long duration ($>2$ s) gamma-ray bursts (GRBs) are believed to arise from the collapse of massive stars \cite{Hjorth+03}, with a small proportion created from the merger of compact objects. Most of these systems are likely formed via standard stellar evolution pathways. However, it has long been thought that a fraction of GRBs may instead be an outcome of dynamical interactions in dense environments, channels which could also contribute significantly to the samples of compact object mergers detected as gravitational wave sources. Here we report the case of GRB 191019A, a long GRB (T_90 = 64.4 +/- 4.5 s) which we pinpoint close (<100 pc projected) to the nucleus of an ancient (>1~Gyr old) host galaxy at z=0.248. The lack of evidence for star formation and deep limits on any supernova emission make a massive star origin difficult to reconcile with observations, while the timescales of the emission rule out a direct interaction with the supermassive black hole in the nucleus of the galaxy, We suggest that the most likely route for progenitor formation is via dynamical interactions in the dense nucleus of the host, consistent with the centres of such galaxies exhibiting interaction rates up to two orders of magnitude larger than typical field galaxies. The burst properties could naturally be explained via compact object mergers involving white dwarfs (WD), neutron stars (NS) or black holes (BH). These may form dynamically in dense stellar clusters, or originate in a gaseous disc around the supermassive black hole. Future electromagnetic and gravitational-wave observations in tandem thus offer a route to probe the dynamical fraction and the details of dynamical interactions in galactic nuclei and other high density stellar systems. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2303.12912v1-abstract-full').style.display = 'none'; document.getElementById('2303.12912v1-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, 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">Accepted to Nature Astronomy. This is the submitted version and will differ from the published version due to modifications in the refereeing process</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2302.07891">arXiv:2302.07891</a> <span> [<a href="https://arxiv.org/pdf/2302.07891">pdf</a>, <a href="https://arxiv.org/format/2302.07891">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="High Energy Astrophysical Phenomena">astro-ph.HE</span> </div> </div> <p class="title is-5 mathjax"> The brightest GRB ever detected: GRB 221009A as a highly luminous event at z = 0.151 </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Malesani%2C+D+B">D. B. Malesani</a>, <a href="/search/astro-ph?searchtype=author&query=Levan%2C+A+J">A. J. Levan</a>, <a href="/search/astro-ph?searchtype=author&query=Izzo%2C+L">L. Izzo</a>, <a href="/search/astro-ph?searchtype=author&query=Postigo%2C+A+d+U">A. de Ugarte Postigo</a>, <a href="/search/astro-ph?searchtype=author&query=Ghirlanda%2C+G">G. Ghirlanda</a>, <a href="/search/astro-ph?searchtype=author&query=Heintz%2C+K+E">K. E. Heintz</a>, <a href="/search/astro-ph?searchtype=author&query=Kann%2C+D+A">D. A. Kann</a>, <a href="/search/astro-ph?searchtype=author&query=Lamb%2C+G+P">G. P. Lamb</a>, <a href="/search/astro-ph?searchtype=author&query=Palmerio%2C+J">J. Palmerio</a>, <a href="/search/astro-ph?searchtype=author&query=Salafia%2C+O+S">O. S. Salafia</a>, <a href="/search/astro-ph?searchtype=author&query=Salvaterra%2C+R">R. Salvaterra</a>, <a href="/search/astro-ph?searchtype=author&query=Tanvir%2C+N+R">N. R. Tanvir</a>, <a href="/search/astro-ph?searchtype=author&query=Fern%C3%A1ndez%2C+J+F+A">J. F. Ag眉铆 Fern谩ndez</a>, <a href="/search/astro-ph?searchtype=author&query=Campana%2C+S">S. Campana</a>, <a href="/search/astro-ph?searchtype=author&query=Chrimes%2C+A+A">A. A. Chrimes</a>, <a href="/search/astro-ph?searchtype=author&query=D%27Avanzo%2C+P">P. D'Avanzo</a>, <a href="/search/astro-ph?searchtype=author&query=D%27Elia%2C+V">V. D'Elia</a>, <a href="/search/astro-ph?searchtype=author&query=Della+Valle%2C+M">M. Della Valle</a>, <a href="/search/astro-ph?searchtype=author&query=De+Pasquale%2C+M">M. De Pasquale</a>, <a href="/search/astro-ph?searchtype=author&query=Fynbo%2C+J+P+U">J. P. U. Fynbo</a>, <a href="/search/astro-ph?searchtype=author&query=Gaspari%2C+N">N. Gaspari</a>, <a href="/search/astro-ph?searchtype=author&query=Gompertz%2C+B+P">B. P. Gompertz</a>, <a href="/search/astro-ph?searchtype=author&query=Hartmann%2C+D+H">D. H. Hartmann</a>, <a href="/search/astro-ph?searchtype=author&query=Hjorth%2C+J">J. Hjorth</a>, <a href="/search/astro-ph?searchtype=author&query=Jakobsson%2C+P">P. Jakobsson</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="2302.07891v1-abstract-short" style="display: inline;"> Context: The extreme luminosity of gamma-ray bursts (GRBs) makes them powerful beacons for studies of the distant Universe. The most luminous bursts are typically detected at moderate/high redshift, where the volume for seeing such rare events is maximized and the star-formation activity is greater than at z = 0. For distant events, not all observations are feasible, such as at TeV energies. Aim… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2302.07891v1-abstract-full').style.display = 'inline'; document.getElementById('2302.07891v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2302.07891v1-abstract-full" style="display: none;"> Context: The extreme luminosity of gamma-ray bursts (GRBs) makes them powerful beacons for studies of the distant Universe. The most luminous bursts are typically detected at moderate/high redshift, where the volume for seeing such rare events is maximized and the star-formation activity is greater than at z = 0. For distant events, not all observations are feasible, such as at TeV energies. Aims: Here we present a spectroscopic redshift measurement for the exceptional GRB 221009A, the brightest GRB observed to date with emission extending well into the TeV regime. Methods: We used the X-shooter spectrograph at the ESO Very Large Telescope (VLT) to obtain simultaneous optical to near-IR spectroscopy of the burst afterglow 0.5 days after the explosion. Results: The spectra exhibit both absorption and emission lines from material in a host galaxy at z = 0.151. Thus GRB 221009A was a relatively nearby burst with a luminosity distance of 745 Mpc. Its host galaxy properties (star-formation rate and metallicity) are consistent with those of LGRB hosts at low redshift. This redshift measurement yields information on the energy of the burst. The inferred isotropic energy release, $E_{\rm iso} > 5 \times 10^{54}$ erg, lies at the high end of the distribution, making GRB 221009A one of the nearest and also most energetic GRBs observed to date. We estimate that such a combination (nearby as well as intrinsically bright) occurs between once every few decades to once per millennium. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2302.07891v1-abstract-full').style.display = 'none'; document.getElementById('2302.07891v1-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 February, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> February 2023. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">9 pages, 4 figures, submitted to Astronomy & 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/2302.07761">arXiv:2302.07761</a> <span> [<a href="https://arxiv.org/pdf/2302.07761">pdf</a>, <a href="https://arxiv.org/format/2302.07761">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/acc2c1">10.3847/2041-8213/acc2c1 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> The first JWST spectrum of a GRB afterglow: No bright supernova in observations of the brightest GRB of all time, GRB 221009A </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Levan%2C+A+J">A. J. Levan</a>, <a href="/search/astro-ph?searchtype=author&query=Lamb%2C+G+P">G. P. Lamb</a>, <a href="/search/astro-ph?searchtype=author&query=Schneider%2C+B">B. Schneider</a>, <a href="/search/astro-ph?searchtype=author&query=Hjorth%2C+J">J. Hjorth</a>, <a href="/search/astro-ph?searchtype=author&query=Zafar%2C+T">T. Zafar</a>, <a href="/search/astro-ph?searchtype=author&query=Postigo%2C+A+d+U">A. de Ugarte Postigo</a>, <a href="/search/astro-ph?searchtype=author&query=Sargent%2C+B">B. Sargent</a>, <a href="/search/astro-ph?searchtype=author&query=Mullally%2C+S+E">S. E. Mullally</a>, <a href="/search/astro-ph?searchtype=author&query=Izzo%2C+L">L. Izzo</a>, <a href="/search/astro-ph?searchtype=author&query=D%27Avanzo%2C+P">P. D'Avanzo</a>, <a href="/search/astro-ph?searchtype=author&query=Burns%2C+E">E. Burns</a>, <a href="/search/astro-ph?searchtype=author&query=Fern%C3%A1ndez%2C+J+F+A">J. F. Ag眉铆 Fern谩ndez</a>, <a href="/search/astro-ph?searchtype=author&query=Barclay%2C+T">T. Barclay</a>, <a href="/search/astro-ph?searchtype=author&query=Bernardini%2C+M+G">M. G. Bernardini</a>, <a href="/search/astro-ph?searchtype=author&query=Bhirombhakdi%2C+K">K. Bhirombhakdi</a>, <a href="/search/astro-ph?searchtype=author&query=Bremer%2C+M">M. Bremer</a>, <a href="/search/astro-ph?searchtype=author&query=Brivio%2C+R">R. Brivio</a>, <a href="/search/astro-ph?searchtype=author&query=Campana%2C+S">S. Campana</a>, <a href="/search/astro-ph?searchtype=author&query=Chrimes%2C+A+A">A. A. Chrimes</a>, <a href="/search/astro-ph?searchtype=author&query=D%27Elia%2C+V">V. D'Elia</a>, <a href="/search/astro-ph?searchtype=author&query=Della+Valle%2C+M">M. Della Valle</a>, <a href="/search/astro-ph?searchtype=author&query=De+Pasquale%2C+M">M. De Pasquale</a>, <a href="/search/astro-ph?searchtype=author&query=Ferro%2C+M">M. Ferro</a>, <a href="/search/astro-ph?searchtype=author&query=Fong%2C+W">W. Fong</a>, <a href="/search/astro-ph?searchtype=author&query=Fruchter%2C+A+S">A. S. Fruchter</a> , et al. (35 additional authors not shown) </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2302.07761v2-abstract-short" style="display: inline;"> We present JWST and Hubble Space Telescope (HST) observations of the afterglow of GRB 221009A, the brightest gamma-ray burst (GRB) ever observed. This includes the first mid-IR spectra of any GRB, obtained with JWST/NIRSPEC (0.6-5.5 micron) and MIRI (5-12 micron), 12 days after the burst. Assuming that the intrinsic spectral slope is a single power-law, with $F_谓 \propto 谓^{-尾}$, we obtain… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2302.07761v2-abstract-full').style.display = 'inline'; document.getElementById('2302.07761v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2302.07761v2-abstract-full" style="display: none;"> We present JWST and Hubble Space Telescope (HST) observations of the afterglow of GRB 221009A, the brightest gamma-ray burst (GRB) ever observed. This includes the first mid-IR spectra of any GRB, obtained with JWST/NIRSPEC (0.6-5.5 micron) and MIRI (5-12 micron), 12 days after the burst. Assuming that the intrinsic spectral slope is a single power-law, with $F_谓 \propto 谓^{-尾}$, we obtain $尾\approx 0.35$, modified by substantial dust extinction with $A_V = 4.9$. This suggests extinction above the notional Galactic value, possibly due to patchy extinction within the Milky Way or dust in the GRB host galaxy. It further implies that the X-ray and optical/IR regimes are not on the same segment of the synchrotron spectrum of the afterglow. If the cooling break lies between the X-ray and optical/IR, then the temporal decay rates would only match a post jet-break model, with electron index $p<2$, and with the jet expanding into a uniform ISM medium. The shape of the JWST spectrum is near-identical in the optical/nIR to X-shooter spectroscopy obtained at 0.5 days and to later time observations with HST. The lack of spectral evolution suggests that any accompanying supernova (SN) is either substantially fainter or bluer than SN 1998bw, the proto-type GRB-SN. Our HST observations also reveal a disc-like host galaxy, viewed close to edge-on, that further complicates the isolation of any supernova component. The host galaxy appears rather typical amongst long-GRB hosts and suggests that the extreme properties of GRB 221009A are not directly tied to its galaxy-scale environment. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2302.07761v2-abstract-full').style.display = 'none'; document.getElementById('2302.07761v2-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, 2023; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 15 February, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> February 2023. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">Accepted for publication to the Astrophysical Journal Letters for the GRB 221009A Special Issue. The results of this paper are under press embargo until March 28, 18 UT. 19 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/2211.16537">arXiv:2211.16537</a> <span> [<a href="https://arxiv.org/pdf/2211.16537">pdf</a>, <a href="https://arxiv.org/format/2211.16537">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/s41550-022-01820-x">10.1038/s41550-022-01820-x <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> The Birth of a Relativistic Jet Following the Disruption of a Star by a Cosmological Black Hole </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Pasham%2C+D+R">Dheeraj R. Pasham</a>, <a href="/search/astro-ph?searchtype=author&query=Lucchini%2C+M">Matteo Lucchini</a>, <a href="/search/astro-ph?searchtype=author&query=Laskar%2C+T">Tanmoy Laskar</a>, <a href="/search/astro-ph?searchtype=author&query=Gompertz%2C+B+P">Benjamin P. Gompertz</a>, <a href="/search/astro-ph?searchtype=author&query=Srivastav%2C+S">Shubham Srivastav</a>, <a href="/search/astro-ph?searchtype=author&query=Nicholl%2C+M">Matt Nicholl</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=Miller-Jones%2C+J+C+A">James C. A. Miller-Jones</a>, <a href="/search/astro-ph?searchtype=author&query=Alexander%2C+K+D">Kate D. Alexander</a>, <a href="/search/astro-ph?searchtype=author&query=Fender%2C+R">Rob Fender</a>, <a href="/search/astro-ph?searchtype=author&query=Smith%2C+G+P">Graham P. Smith</a>, <a href="/search/astro-ph?searchtype=author&query=Fulton%2C+M+D">Michael D. Fulton</a>, <a href="/search/astro-ph?searchtype=author&query=Dewangan%2C+G">Gulab Dewangan</a>, <a href="/search/astro-ph?searchtype=author&query=Gendreau%2C+K">Keith Gendreau</a>, <a href="/search/astro-ph?searchtype=author&query=Coughlin%2C+E+R">Eric R. Coughlin</a>, <a href="/search/astro-ph?searchtype=author&query=Rhodes%2C+L">Lauren Rhodes</a>, <a href="/search/astro-ph?searchtype=author&query=Horesh%2C+A">Assaf Horesh</a>, <a href="/search/astro-ph?searchtype=author&query=van+Velzen%2C+S">Sjoert van Velzen</a>, <a href="/search/astro-ph?searchtype=author&query=Sfaradi%2C+I">Itai Sfaradi</a>, <a href="/search/astro-ph?searchtype=author&query=Guolo%2C+M">Muryel Guolo</a>, <a href="/search/astro-ph?searchtype=author&query=Segura%2C+N+C">N. Castro Segura</a>, <a href="/search/astro-ph?searchtype=author&query=Aamer%2C+A">Aysha Aamer</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=Arcavi%2C+I">Iair Arcavi</a>, <a href="/search/astro-ph?searchtype=author&query=Brennan%2C+S+J">Sean J. Brennan</a> , et al. (41 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="2211.16537v1-abstract-short" style="display: inline;"> A black hole can launch a powerful relativistic jet after it tidally disrupts a star. If this jet fortuitously aligns with our line of sight, the overall brightness is Doppler boosted by several orders of magnitude. Consequently, such on-axis relativistic tidal disruption events (TDEs) have the potential to unveil cosmological (redshift $z>$1) quiescent black holes and are ideal test beds to under… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2211.16537v1-abstract-full').style.display = 'inline'; document.getElementById('2211.16537v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2211.16537v1-abstract-full" style="display: none;"> A black hole can launch a powerful relativistic jet after it tidally disrupts a star. If this jet fortuitously aligns with our line of sight, the overall brightness is Doppler boosted by several orders of magnitude. Consequently, such on-axis relativistic tidal disruption events (TDEs) have the potential to unveil cosmological (redshift $z>$1) quiescent black holes and are ideal test beds to understand the radiative mechanisms operating in super-Eddington jets. Here, we present multi-wavelength (X-ray, UV, optical, and radio) observations of the optically discovered transient \target at $z=1.193$. Its unusual X-ray properties, including a peak observed luminosity of $\gtrsim$10$^{48}$ erg s$^{-1}$, systematic variability on timescales as short as 1000 seconds, and overall duration lasting more than 30 days in the rest-frame are traits associated with relativistic TDEs. The X-ray to radio spectral energy distributions spanning 5-50 days after discovery can be explained as synchrotron emission from a relativistic jet (radio), synchrotron self-Compton (X-rays), and thermal emission similar to that seen in low-redshift TDEs (UV/optical). Our modeling implies a beamed, highly relativistic jet akin to blazars but requires extreme matter-domination, i.e, high ratio of electron-to-magnetic field energy densities in the jet, and challenges our theoretical understanding of jets. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2211.16537v1-abstract-full').style.display = 'none'; document.getElementById('2211.16537v1-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">To appear in Nature Astronomy on 30th November 2022. Also see here for an animation explaining the result: https://youtu.be/MQHdSbxuznY</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2209.06375">arXiv:2209.06375</a> <span> [<a href="https://arxiv.org/pdf/2209.06375">pdf</a>, <a href="https://arxiv.org/format/2209.06375">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Computer Vision and Pattern Recognition">cs.CV</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/stac3103">10.1093/mnras/stac3103 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Self-Supervised Clustering on Image-Subtracted Data with Deep-Embedded Self-Organizing Map </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Mong%2C+Y+-">Y. -L. Mong</a>, <a href="/search/astro-ph?searchtype=author&query=Ackley%2C+K">K. Ackley</a>, <a href="/search/astro-ph?searchtype=author&query=Killestein%2C+T+L">T. L. Killestein</a>, <a href="/search/astro-ph?searchtype=author&query=Galloway%2C+D+K">D. K. Galloway</a>, <a href="/search/astro-ph?searchtype=author&query=Dyer%2C+M">M. Dyer</a>, <a href="/search/astro-ph?searchtype=author&query=Cutter%2C+R">R. Cutter</a>, <a href="/search/astro-ph?searchtype=author&query=Brown%2C+M+J+I">M. J. I. Brown</a>, <a href="/search/astro-ph?searchtype=author&query=Lyman%2C+J">J. Lyman</a>, <a href="/search/astro-ph?searchtype=author&query=Ulaczyk%2C+K">K. Ulaczyk</a>, <a href="/search/astro-ph?searchtype=author&query=Steeghs%2C+D">D. Steeghs</a>, <a href="/search/astro-ph?searchtype=author&query=Dhillon%2C+V">V. Dhillon</a>, <a href="/search/astro-ph?searchtype=author&query=O%27Brien%2C+P">P. O'Brien</a>, <a href="/search/astro-ph?searchtype=author&query=Ramsay%2C+G">G. Ramsay</a>, <a href="/search/astro-ph?searchtype=author&query=Noysena%2C+K">K. Noysena</a>, <a href="/search/astro-ph?searchtype=author&query=Kotak%2C+R">R. Kotak</a>, <a href="/search/astro-ph?searchtype=author&query=Breton%2C+R">R. Breton</a>, <a href="/search/astro-ph?searchtype=author&query=Nuttall%2C+L">L. Nuttall</a>, <a href="/search/astro-ph?searchtype=author&query=Palle%2C+E">E. Palle</a>, <a href="/search/astro-ph?searchtype=author&query=Pollacco%2C+D">D. Pollacco</a>, <a href="/search/astro-ph?searchtype=author&query=Thrane%2C+E">E. Thrane</a>, <a href="/search/astro-ph?searchtype=author&query=Awiphan%2C+S">S. Awiphan</a>, <a href="/search/astro-ph?searchtype=author&query=Burhanudin%2C+U">U. Burhanudin</a>, <a href="/search/astro-ph?searchtype=author&query=Chote%2C+P">P. Chote</a>, <a href="/search/astro-ph?searchtype=author&query=Chrimes%2C+A">A. Chrimes</a>, <a href="/search/astro-ph?searchtype=author&query=Daw%2C+E">E. Daw</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="2209.06375v1-abstract-short" style="display: inline;"> Developing an effective automatic classifier to separate genuine sources from artifacts is essential for transient follow-ups in wide-field optical surveys. The identification of transient detections from the subtraction artifacts after the image differencing process is a key step in such classifiers, known as real-bogus classification problem. We apply a self-supervised machine learning model, th… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2209.06375v1-abstract-full').style.display = 'inline'; document.getElementById('2209.06375v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2209.06375v1-abstract-full" style="display: none;"> Developing an effective automatic classifier to separate genuine sources from artifacts is essential for transient follow-ups in wide-field optical surveys. The identification of transient detections from the subtraction artifacts after the image differencing process is a key step in such classifiers, known as real-bogus classification problem. We apply a self-supervised machine learning model, the deep-embedded self-organizing map (DESOM) to this "real-bogus" classification problem. DESOM combines an autoencoder and a self-organizing map to perform clustering in order to distinguish between real and bogus detections, based on their dimensionality-reduced representations. We use 32x32 normalized detection thumbnails as the input of DESOM. We demonstrate different model training approaches, and find that our best DESOM classifier shows a missed detection rate of 6.6% with a false positive rate of 1.5%. DESOM offers a more nuanced way to fine-tune the decision boundary identifying likely real detections when used in combination with other types of classifiers, for example built on neural networks or decision trees. We also discuss other potential usages of DESOM and its limitations. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2209.06375v1-abstract-full').style.display = 'none'; document.getElementById('2209.06375v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 13 September, 2022; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> September 2022. </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2208.09000">arXiv:2208.09000</a> <span> [<a href="https://arxiv.org/pdf/2208.09000">pdf</a>, <a href="https://arxiv.org/format/2208.09000">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="High Energy Astrophysical Phenomena">astro-ph.HE</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1051/0004-6361/202244751">10.1051/0004-6361/202244751 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Panning for gold, but finding helium: discovery of the ultra-stripped supernova SN2019wxt from gravitational-wave follow-up observations </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Agudo%2C+I">I. Agudo</a>, <a href="/search/astro-ph?searchtype=author&query=Amati%2C+L">L. Amati</a>, <a href="/search/astro-ph?searchtype=author&query=An%2C+T">T. An</a>, <a href="/search/astro-ph?searchtype=author&query=Bauer%2C+F+E">F. E. Bauer</a>, <a href="/search/astro-ph?searchtype=author&query=Benetti%2C+S">S. Benetti</a>, <a href="/search/astro-ph?searchtype=author&query=Bernardini%2C+M+G">M. G. Bernardini</a>, <a href="/search/astro-ph?searchtype=author&query=Beswick%2C+R">R. Beswick</a>, <a href="/search/astro-ph?searchtype=author&query=Bhirombhakdi%2C+K">K. Bhirombhakdi</a>, <a href="/search/astro-ph?searchtype=author&query=de+Boer%2C+T">T. de Boer</a>, <a href="/search/astro-ph?searchtype=author&query=Branchesi%2C+M">M. Branchesi</a>, <a href="/search/astro-ph?searchtype=author&query=Brennan%2C+S+J">S. J. Brennan</a>, <a href="/search/astro-ph?searchtype=author&query=Caballero-Garc%C3%ADa%2C+M+D">M. D. Caballero-Garc铆a</a>, <a href="/search/astro-ph?searchtype=author&query=Cappellaro%2C+E">E. Cappellaro</a>, <a href="/search/astro-ph?searchtype=author&query=Rodr%C3%ADguez%2C+N+C">N. Castro Rodr铆guez</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=Chambers%2C+K+C">K. C. Chambers</a>, <a href="/search/astro-ph?searchtype=author&query=Chassande-Mottin%2C+E">E. Chassande-Mottin</a>, <a href="/search/astro-ph?searchtype=author&query=Chaty%2C+S">S. Chaty</a>, <a href="/search/astro-ph?searchtype=author&query=Chen%2C+T+-">T. -W. Chen</a>, <a href="/search/astro-ph?searchtype=author&query=Coleiro%2C+A">A. Coleiro</a>, <a href="/search/astro-ph?searchtype=author&query=Covino%2C+S">S. Covino</a>, <a href="/search/astro-ph?searchtype=author&query=D%27Ammando%2C+F">F. D'Ammando</a>, <a href="/search/astro-ph?searchtype=author&query=D%27Avanzo%2C+P">P. D'Avanzo</a>, <a href="/search/astro-ph?searchtype=author&query=D%27Elia%2C+V">V. D'Elia</a>, <a href="/search/astro-ph?searchtype=author&query=Fiore%2C+A">A. Fiore</a> , et al. (74 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="2208.09000v3-abstract-short" style="display: inline;"> We present the results from multi-wavelength observations of a transient discovered during the follow-up of S191213g, a gravitational wave (GW) event reported by the LIGO-Virgo Collaboration as a possible binary neutron star merger in a low latency search. This search yielded SN2019wxt, a young transient in a galaxy whose sky position (in the 80\% GW contour) and distance ($\sim$150\,Mpc) were pla… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2208.09000v3-abstract-full').style.display = 'inline'; document.getElementById('2208.09000v3-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2208.09000v3-abstract-full" style="display: none;"> We present the results from multi-wavelength observations of a transient discovered during the follow-up of S191213g, a gravitational wave (GW) event reported by the LIGO-Virgo Collaboration as a possible binary neutron star merger in a low latency search. This search yielded SN2019wxt, a young transient in a galaxy whose sky position (in the 80\% GW contour) and distance ($\sim$150\,Mpc) were plausibly compatible with the localisation uncertainty of the GW event. Initially, the transient's tightly constrained age, its relatively faint peak magnitude ($M_i \sim -16.7$\,mag) and the $r-$band decline rate of $\sim 1$\,mag per 5\,days appeared suggestive of a compact binary merger. However, SN2019wxt spectroscopically resembled a type Ib supernova, and analysis of the optical-near-infrared evolution rapidly led to the conclusion that while it could not be associated with S191213g, it nevertheless represented an extreme outcome of stellar evolution. By modelling the light curve, we estimated an ejecta mass of $\sim 0.1\,M_\odot$, with $^{56}$Ni comprising $\sim 20\%$ of this. We were broadly able to reproduce its spectral evolution with a composition dominated by helium and oxygen, with trace amounts of calcium. We considered various progenitors that could give rise to the observed properties of SN2019wxt, and concluded that an ultra-stripped origin in a binary system is the most likely explanation. Disentangling electromagnetic counterparts to GW events from transients such as SN2019wxt is challenging: in a bid to characterise the level of contamination, we estimated the rate of events with properties comparable to those of SN2019wxt and found that $\sim 1$ such event per week can occur within the typical GW localisation area of O4 alerts out to a luminosity distance of 500\,Mpc, beyond which it would become fainter than the typical depth of current electromagnetic follow-up campaigns. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2208.09000v3-abstract-full').style.display = 'none'; document.getElementById('2208.09000v3-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 June, 2023; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 18 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">By the ENGRAVE collaboration (engrave-eso.org). 35 pages, 20 figures, final version accepted by A&A</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> A&A 675, A201 (2023) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2208.00973">arXiv:2208.00973</a> <span> [<a href="https://arxiv.org/pdf/2208.00973">pdf</a>, <a href="https://arxiv.org/format/2208.00973">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/10.1093/mnras/stac3626">10.1093/mnras/stac3626 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Mechanisms for high spin in black-hole neutron-star binaries and kilonova emission: inheritance and accretion </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Steinle%2C+N">Nathan Steinle</a>, <a href="/search/astro-ph?searchtype=author&query=Gompertz%2C+B+P">Benjamin P. Gompertz</a>, <a href="/search/astro-ph?searchtype=author&query=Nicholl%2C+M">Matt Nicholl</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="2208.00973v2-abstract-short" style="display: inline;"> A black-hole neutron-star binary merger can lead to an electromagnetic counterpart called a kilonova if the neutron star is disrupted prior to merger. The observability of a kilonova depends on the amount of neutron star ejecta, which is sensitive to the aligned component of the black hole spin. We explore the dependence of the ejected mass on two main mechanisms that provide high black hole spin… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2208.00973v2-abstract-full').style.display = 'inline'; document.getElementById('2208.00973v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2208.00973v2-abstract-full" style="display: none;"> A black-hole neutron-star binary merger can lead to an electromagnetic counterpart called a kilonova if the neutron star is disrupted prior to merger. The observability of a kilonova depends on the amount of neutron star ejecta, which is sensitive to the aligned component of the black hole spin. We explore the dependence of the ejected mass on two main mechanisms that provide high black hole spin in isolated stellar binaries. When the black hole inherits a high spin from a Wolf-Rayet star that was born with least $\sim$ 10% of its breakup spin under weak stellar core-envelope coupling, relevant for all formation pathways, the median of the ejected mass is $\gtrsim$ $10^{-2}$ M$_{\odot}$. Though only possible for certain formation pathways, similar ejected mass results when the black hole accretes $\gtrsim$ 20% of its companion's envelope to gain a high spin. Together, these signatures suggest that a population analysis of black-hole neutron-star binary mergers with observed kilonovae may help distinguish between mechanisms for spin and possible formation pathways. We show that these kilonovae will be difficult to detect with current capabilities, but that future facilities, such as the Vera Rubin Observatory, can do so even if the aligned dimensionless spin of the black hole is as low as $\sim$ 0.2. Our model predicts kilonovae as bright as $M_i$ $\sim$ -14.5 for an aligned black hole spin of $\sim$ 0.9 and mass ratio Q = 3.6. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2208.00973v2-abstract-full').style.display = 'none'; document.getElementById('2208.00973v2-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 2 February, 2023; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 1 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">Journal ref:</span> Monthly Notices of the Royal Astronomical Society, Volume 519, Issue 1, February 2023, Pages 891 - 901 </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2206.13595">arXiv:2206.13595</a> <span> [<a href="https://arxiv.org/pdf/2206.13595">pdf</a>, <a href="https://arxiv.org/format/2206.13595">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/stac1796">10.1093/mnras/stac1796 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Towards an understanding of long gamma-ray burst environments through circumstellar medium population synthesis predictions </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Chrimes%2C+A+A">A. A. Chrimes</a>, <a href="/search/astro-ph?searchtype=author&query=Gompertz%2C+B+P">B. P. Gompertz</a>, <a href="/search/astro-ph?searchtype=author&query=Kann%2C+D+A">D. A. Kann</a>, <a href="/search/astro-ph?searchtype=author&query=van+Marle%2C+A+J">A. J. van Marle</a>, <a href="/search/astro-ph?searchtype=author&query=Eldridge%2C+J+J">J. J. Eldridge</a>, <a href="/search/astro-ph?searchtype=author&query=Groot%2C+P+J">P. J. Groot</a>, <a href="/search/astro-ph?searchtype=author&query=Laskar%2C+T">T. Laskar</a>, <a href="/search/astro-ph?searchtype=author&query=Levan%2C+A+J">A. J. Levan</a>, <a href="/search/astro-ph?searchtype=author&query=Nicholl%2C+M">M. Nicholl</a>, <a href="/search/astro-ph?searchtype=author&query=Stanway%2C+E+R">E. R. Stanway</a>, <a href="/search/astro-ph?searchtype=author&query=Wiersema%2C+K">K. Wiersema</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="2206.13595v1-abstract-short" style="display: inline;"> The temporal and spectral evolution of gamma-ray burst (GRB) afterglows can be used to infer the density and density profile of the medium through which the shock is propagating. In long-duration (core-collapse) GRBs, the circumstellar medium (CSM) is expected to resemble a wind-blown bubble, with a termination shock separating the stellar wind and the interstellar medium (ISM). A long standing pr… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2206.13595v1-abstract-full').style.display = 'inline'; document.getElementById('2206.13595v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2206.13595v1-abstract-full" style="display: none;"> The temporal and spectral evolution of gamma-ray burst (GRB) afterglows can be used to infer the density and density profile of the medium through which the shock is propagating. In long-duration (core-collapse) GRBs, the circumstellar medium (CSM) is expected to resemble a wind-blown bubble, with a termination shock separating the stellar wind and the interstellar medium (ISM). A long standing problem is that flat density profiles, indicative of the ISM, are often found at lower radii than expected for a massive star progenitor. Furthermore, the presence of both wind-like environments at high radii and ISM-like environments at low radii remains a mystery. In this paper, we perform a 'CSM population synthesis' with long GRB progenitor stellar evolution models. Analytic results for the evolution of wind blown bubbles are adjusted through comparison with a grid of 2D hydrodynamical simulations. Predictions for the emission radii, ratio of ISM to wind-like environments, wind and ISM densities are compared with the largest sample of afterglow-derived parameters yet compiled, which we make available for the community. We find that high ISM densities around 1000/cm3 best reproduce observations. If long GRBs instead occur in typical ISM densities of approximately 1/cm3, then the discrepancy between theory and observations is shown to persist at a population level. We discuss possible explanations for the origin of variety in long GRB afterglows, and for the overall trend of CSM modelling to over-predict the termination shock radius. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2206.13595v1-abstract-full').style.display = 'none'; document.getElementById('2206.13595v1-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">22 pages, 15 figures, 4 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/2205.12750">arXiv:2205.12750</a> <span> [<a href="https://arxiv.org/pdf/2205.12750">pdf</a>, <a href="https://arxiv.org/format/2205.12750">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="High Energy Astrophysical Phenomena">astro-ph.HE</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1051/0004-6361/202142919">10.1051/0004-6361/202142919 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> VLBI observations of GRB 201015A, a relatively faint GRB with a hint of Very High Energy gamma-ray emission </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Giarratana%2C+S">S. Giarratana</a>, <a href="/search/astro-ph?searchtype=author&query=Rhodes%2C+L">L. Rhodes</a>, <a href="/search/astro-ph?searchtype=author&query=Marcote%2C+B">B. Marcote</a>, <a href="/search/astro-ph?searchtype=author&query=Fender%2C+R">R. Fender</a>, <a href="/search/astro-ph?searchtype=author&query=Ghirlanda%2C+G">G. Ghirlanda</a>, <a href="/search/astro-ph?searchtype=author&query=Giroletti%2C+M">M. Giroletti</a>, <a href="/search/astro-ph?searchtype=author&query=Nava%2C+L">L. Nava</a>, <a href="/search/astro-ph?searchtype=author&query=Paredes%2C+J+M">J. M. Paredes</a>, <a href="/search/astro-ph?searchtype=author&query=Ravasio%2C+M+E">M. E. Ravasio</a>, <a href="/search/astro-ph?searchtype=author&query=Ribo%2C+M">M. Ribo</a>, <a href="/search/astro-ph?searchtype=author&query=Patel%2C+M">M. Patel</a>, <a href="/search/astro-ph?searchtype=author&query=Rastinejad%2C+J">J. Rastinejad</a>, <a href="/search/astro-ph?searchtype=author&query=Schroeder%2C+G">G. Schroeder</a>, <a href="/search/astro-ph?searchtype=author&query=Fong%2C+W">W. Fong</a>, <a href="/search/astro-ph?searchtype=author&query=Gompertz%2C+B+P">B. P. Gompertz</a>, <a href="/search/astro-ph?searchtype=author&query=Levan%2C+A+J">A. J. Levan</a>, <a href="/search/astro-ph?searchtype=author&query=O%27Brien%2C+P">P. O'Brien</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2205.12750v1-abstract-short" style="display: inline;"> GRB 201015A is a long-duration Gamma-Ray Burst (GRB) which was detected at very high energies (> 100 GeV) using the MAGIC telescopes. If confirmed, this would be the fifth and least luminous GRB ever detected at this energies. We performed a radio follow-up of GRB 201015A over twelve different epochs, from 1.4 to 117 days post-burst, with the Karl G. Jansky Very Large Array, e-MERLIN and the Europ… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2205.12750v1-abstract-full').style.display = 'inline'; document.getElementById('2205.12750v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2205.12750v1-abstract-full" style="display: none;"> GRB 201015A is a long-duration Gamma-Ray Burst (GRB) which was detected at very high energies (> 100 GeV) using the MAGIC telescopes. If confirmed, this would be the fifth and least luminous GRB ever detected at this energies. We performed a radio follow-up of GRB 201015A over twelve different epochs, from 1.4 to 117 days post-burst, with the Karl G. Jansky Very Large Array, e-MERLIN and the European VLBI Network. We included optical and X-rays observations, performed with the Multiple Mirror Telescope and the Chandra X-ray Observatory respectively, together with publicly available data. We detected a point-like transient, consistent with the position of GRB 201015A until 23 and 47 days post-burst at 1.5 and 5 GHz, respectively. The source was detected also in both optical (1.4 and 2.2 days post-burst) and X-ray (8.4 and 13.6 days post-burst) observations. The multi-wavelength afterglow light curves can be explained with the standard model for a GRB seen on-axis, which expands and decelerates into a medium with a homogeneous density, while a circumburst medium with a wind-like profile is disfavoured. Notwithstanding the high resolution provided by the VLBI, we could not pinpoint any expansion or centroid displacement of the outflow. If the GRB is seen at the viewing angle which maximises the apparent velocity, we estimate that the Lorentz factor for the possible proper motion is $螕_伪$ < 40 in right ascension and $螕_未$ < 61 in declination. On the other hand, if the GRB is seen on-axis, the size of the afterglow is <5 pc and <16 pc at 25 and 47 days. Finally, the early peak in the optical light curve suggests the presence of a reverse shock component before 0.01 days from the burst. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2205.12750v1-abstract-full').style.display = 'none'; document.getElementById('2205.12750v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 25 May, 2022; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> May 2022. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">Accepted for publication in Astronomy & Astrophysics, 11 pages, 3 figures</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> A&A 664, A36 (2022) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2205.05008">arXiv:2205.05008</a> <span> [<a href="https://arxiv.org/pdf/2205.05008">pdf</a>, <a href="https://arxiv.org/format/2205.05008">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/s41550-022-01819-4">10.1038/s41550-022-01819-4 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> The case for a minute-long merger-driven gamma-ray burst from fast-cooling synchrotron emission </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Gompertz%2C+B+P">B. P. Gompertz</a>, <a href="/search/astro-ph?searchtype=author&query=Ravasio%2C+M+E">M. E. Ravasio</a>, <a href="/search/astro-ph?searchtype=author&query=Nicholl%2C+M">M. Nicholl</a>, <a href="/search/astro-ph?searchtype=author&query=Levan%2C+A+J">A. J. Levan</a>, <a href="/search/astro-ph?searchtype=author&query=Metzger%2C+B+D">B. D. Metzger</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=Lamb%2C+G+P">G. P. Lamb</a>, <a href="/search/astro-ph?searchtype=author&query=Fong%2C+W">W. Fong</a>, <a href="/search/astro-ph?searchtype=author&query=Malesani%2C+D+B">D. B. Malesani</a>, <a href="/search/astro-ph?searchtype=author&query=Rastinejad%2C+J+C">J. C. Rastinejad</a>, <a href="/search/astro-ph?searchtype=author&query=Tanvir%2C+N+R">N. R. Tanvir</a>, <a href="/search/astro-ph?searchtype=author&query=Evans%2C+P+A">P. A. Evans</a>, <a href="/search/astro-ph?searchtype=author&query=Jonker%2C+P+G">P. G. Jonker</a>, <a href="/search/astro-ph?searchtype=author&query=Page%2C+K+L">K. L. Page</a>, <a href="/search/astro-ph?searchtype=author&query=Pe%27er%2C+A">A. Pe'er</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2205.05008v2-abstract-short" style="display: inline;"> For decades, gamma-ray bursts (GRBs) have been broadly divided into `long'- and `short'-duration bursts, lasting more or less than 2s, respectively. However, this dichotomy does not map perfectly to the two progenitor channels that are known to produce GRBs -- the merger of compact objects (merger-GRBs) or the collapse of massive stars (collapsar-GRBs). In particular, the merger-GRBs population ma… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2205.05008v2-abstract-full').style.display = 'inline'; document.getElementById('2205.05008v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2205.05008v2-abstract-full" style="display: none;"> For decades, gamma-ray bursts (GRBs) have been broadly divided into `long'- and `short'-duration bursts, lasting more or less than 2s, respectively. However, this dichotomy does not map perfectly to the two progenitor channels that are known to produce GRBs -- the merger of compact objects (merger-GRBs) or the collapse of massive stars (collapsar-GRBs). In particular, the merger-GRBs population may also include bursts with a short, hard $\lesssim$2s spike and subsequent longer, softer extended emission (EE). The recent discovery of a kilonova -- the radioactive glow of heavy elements made in neutron star mergers -- in the 50s-duration GRB 211211A further demonstrates that mergers can drive long, complex GRBs that mimic the collapsar population. Here we present a detailed temporal and spectral analysis of the high-energy emission of GRB 211211A. We demonstrate that the emission has a purely synchrotron origin, with both the peak and cooling frequencies moving through the $纬$-ray band down to the X-rays, and that the rapidly-evolving spectrum drives the EE signature at late times. The identification of such spectral evolution in a merger-GRB opens avenues for diagnostics of the progenitor type. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2205.05008v2-abstract-full').style.display = 'none'; document.getElementById('2205.05008v2-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 14 December, 2022; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 10 May, 2022; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> May 2022. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">Author's final submitted version. 6 figures, 5 tables. The Supplementary Information .tex file is included</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2204.10864">arXiv:2204.10864</a> <span> [<a href="https://arxiv.org/pdf/2204.10864">pdf</a>, <a href="https://arxiv.org/format/2204.10864">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/s41586-022-05390-w">10.1038/s41586-022-05390-w <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> A Kilonova Following a Long-Duration Gamma-Ray Burst at 350 Mpc </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Rastinejad%2C+J+C">J. C. Rastinejad</a>, <a href="/search/astro-ph?searchtype=author&query=Gompertz%2C+B+P">B. P. Gompertz</a>, <a href="/search/astro-ph?searchtype=author&query=Levan%2C+A+J">A. J. Levan</a>, <a href="/search/astro-ph?searchtype=author&query=Fong%2C+W">W. Fong</a>, <a href="/search/astro-ph?searchtype=author&query=Nicholl%2C+M">M. Nicholl</a>, <a href="/search/astro-ph?searchtype=author&query=Lamb%2C+G+P">G. P. Lamb</a>, <a href="/search/astro-ph?searchtype=author&query=Malesani%2C+D+B">D. B. Malesani</a>, <a href="/search/astro-ph?searchtype=author&query=Nugent%2C+A+E">A. E. Nugent</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=Tanvir%2C+N+R">N. R. Tanvir</a>, <a href="/search/astro-ph?searchtype=author&query=Postigo%2C+A+d+U">A. de Ugarte Postigo</a>, <a href="/search/astro-ph?searchtype=author&query=Kilpatrick%2C+C+D">C. D. Kilpatrick</a>, <a href="/search/astro-ph?searchtype=author&query=Moore%2C+C+J">C. J. Moore</a>, <a href="/search/astro-ph?searchtype=author&query=Metzger%2C+B+D">B. D. Metzger</a>, <a href="/search/astro-ph?searchtype=author&query=Ravasio%2C+M+E">M. E. Ravasio</a>, <a href="/search/astro-ph?searchtype=author&query=Rossi%2C+A">A. Rossi</a>, <a href="/search/astro-ph?searchtype=author&query=Schroeder%2C+G">G. Schroeder</a>, <a href="/search/astro-ph?searchtype=author&query=Jencson%2C+J">J. Jencson</a>, <a href="/search/astro-ph?searchtype=author&query=Sand%2C+D+J">D. J. Sand</a>, <a href="/search/astro-ph?searchtype=author&query=Smith%2C+N">N. Smith</a>, <a href="/search/astro-ph?searchtype=author&query=Fern%C3%A1ndez%2C+J+F+A">J. F. Ag眉铆 Fern谩ndez</a>, <a href="/search/astro-ph?searchtype=author&query=Berger%2C+E">E. Berger</a>, <a href="/search/astro-ph?searchtype=author&query=Blanchard%2C+P+K">P. K. Blanchard</a>, <a href="/search/astro-ph?searchtype=author&query=Chornock%2C+R">R. Chornock</a>, <a href="/search/astro-ph?searchtype=author&query=Cobb%2C+B+E">B. E. Cobb</a> , et al. (10 additional authors not shown) </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2204.10864v3-abstract-short" style="display: inline;"> Here, we report the discovery of a kilonova associated with the nearby (350 Mpc) minute-duration GRB 211211A. In tandem with deep optical limits that rule out the presence of an accompanying supernova to $M_I > -13$ mag at 17.7 days post-burst, the identification of a kilonova confirms that this burst's progenitor was a compact object merger. While the spectrally softer tail in GRB 211211A's gamma… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2204.10864v3-abstract-full').style.display = 'inline'; document.getElementById('2204.10864v3-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2204.10864v3-abstract-full" style="display: none;"> Here, we report the discovery of a kilonova associated with the nearby (350 Mpc) minute-duration GRB 211211A. In tandem with deep optical limits that rule out the presence of an accompanying supernova to $M_I > -13$ mag at 17.7 days post-burst, the identification of a kilonova confirms that this burst's progenitor was a compact object merger. While the spectrally softer tail in GRB 211211A's gamma-ray light curve is reminiscent of previous extended emission short GRBs (EE-SGRBs), its prompt, bright spikes last $\gtrsim 12$ s, separating it from past EE-SGRBs. GRB 211211A's kilonova has a similar luminosity, duration and color to AT2017gfo, the kilonova found in association with the gravitational wave (GW)-detected binary neutron star (BNS) merger GW170817. We find that the merger ejected $\approx 0.04 M_{\odot}$ of r-process-rich material, and is consistent with the merger of two neutron stars (NSs) with masses close to the canonical $1.4 M_{\odot}$. This discovery implies that GRBs with long, complex light curves can be spawned from compact object merger events and that a population of kilonovae following GRBs with durations $\gg 2$ s should be accounted for in calculations of the NS merger r-process contribution and rate. At 350 Mpc, the current network of GW interferometers at design sensitivity would have detected the merger precipitating GRB 211211A, had it been operating at the time of the event. Further searches for GW signals coincident with long GRBs are therefore a promising route for future multi-messenger astronomy. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2204.10864v3-abstract-full').style.display = 'none'; document.getElementById('2204.10864v3-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 26 August, 2022; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 22 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">Submitted. 69 pages, 11 figures, 3 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/2110.05539">arXiv:2110.05539</a> <span> [<a href="https://arxiv.org/pdf/2110.05539">pdf</a>, <a href="https://arxiv.org/format/2110.05539">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/stac013">10.1093/mnras/stac013 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> The Gravitational-wave Optical Transient Observer (GOTO): prototype performance and prospects for transient science </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Steeghs%2C+D">D. Steeghs</a>, <a href="/search/astro-ph?searchtype=author&query=Galloway%2C+D+K">D. K. Galloway</a>, <a href="/search/astro-ph?searchtype=author&query=Ackley%2C+K">K. Ackley</a>, <a href="/search/astro-ph?searchtype=author&query=Dyer%2C+M+J">M. J. Dyer</a>, <a href="/search/astro-ph?searchtype=author&query=Lyman%2C+J">J. Lyman</a>, <a href="/search/astro-ph?searchtype=author&query=Ulaczyk%2C+K">K. Ulaczyk</a>, <a href="/search/astro-ph?searchtype=author&query=Cutter%2C+R">R. Cutter</a>, <a href="/search/astro-ph?searchtype=author&query=Mong%2C+Y+L">Y. L. Mong</a>, <a href="/search/astro-ph?searchtype=author&query=Dhillon%2C+V">V. Dhillon</a>, <a href="/search/astro-ph?searchtype=author&query=O%27Brien%2C+P">P. O'Brien</a>, <a href="/search/astro-ph?searchtype=author&query=Ramsay%2C+G">G. Ramsay</a>, <a href="/search/astro-ph?searchtype=author&query=Poshyachinda%2C+S">S. Poshyachinda</a>, <a href="/search/astro-ph?searchtype=author&query=Kotak%2C+R">R. Kotak</a>, <a href="/search/astro-ph?searchtype=author&query=Nuttall%2C+L+K">L. K. Nuttall</a>, <a href="/search/astro-ph?searchtype=author&query=Palle%2C+E">E. Palle</a>, <a href="/search/astro-ph?searchtype=author&query=Breton%2C+R+P">R. P. Breton</a>, <a href="/search/astro-ph?searchtype=author&query=Pollacco%2C+D">D. Pollacco</a>, <a href="/search/astro-ph?searchtype=author&query=Thrane%2C+E">E. Thrane</a>, <a href="/search/astro-ph?searchtype=author&query=Aukkaravittayapun%2C+S">S. Aukkaravittayapun</a>, <a href="/search/astro-ph?searchtype=author&query=Awiphan%2C+S">S. Awiphan</a>, <a href="/search/astro-ph?searchtype=author&query=Burhanudin%2C+U">U. Burhanudin</a>, <a href="/search/astro-ph?searchtype=author&query=Chote%2C+P">P. Chote</a>, <a href="/search/astro-ph?searchtype=author&query=Chrimes%2C+A">A. Chrimes</a>, <a href="/search/astro-ph?searchtype=author&query=Daw%2C+E">E. Daw</a>, <a href="/search/astro-ph?searchtype=author&query=Duffy%2C+C">C. Duffy</a> , et al. (28 additional authors not shown) </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2110.05539v1-abstract-short" style="display: inline;"> The Gravitational-wave Optical Transient Observer (GOTO) is an array of wide-field optical telescopes, designed to exploit new discoveries from the next generation of gravitational wave detectors (LIGO, Virgo, KAGRA), study rapidly evolving transients, and exploit multi-messenger opportunities arising from neutrino and very high energy gamma-ray triggers. In addition to a rapid response mode, the… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2110.05539v1-abstract-full').style.display = 'inline'; document.getElementById('2110.05539v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2110.05539v1-abstract-full" style="display: none;"> The Gravitational-wave Optical Transient Observer (GOTO) is an array of wide-field optical telescopes, designed to exploit new discoveries from the next generation of gravitational wave detectors (LIGO, Virgo, KAGRA), study rapidly evolving transients, and exploit multi-messenger opportunities arising from neutrino and very high energy gamma-ray triggers. In addition to a rapid response mode, the array will also perform a sensitive, all-sky transient survey with few day cadence. The facility features a novel, modular design with multiple 40-cm wide-field reflectors on a single mount. In June 2017 the GOTO collaboration deployed the initial project prototype, with 4 telescope units, at the Roque de los Muchachos Observatory (ORM), La Palma, Canary Islands. Here we describe the deployment, commissioning, and performance of the prototype hardware, and discuss the impact of these findings on the final GOTO design. We also offer an initial assessment of the science prospects for the full GOTO facility that employs 32 telescope units across two sites. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2110.05539v1-abstract-full').style.display = 'none'; document.getElementById('2110.05539v1-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 October, 2021; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> October 2021. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">19 pages, 16 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/2109.09714">arXiv:2109.09714</a> <span> [<a href="https://arxiv.org/pdf/2109.09714">pdf</a>, <a href="https://arxiv.org/format/2109.09714">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/stac1473">10.1093/mnras/stac1473 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Exploring compact binary merger host galaxies and environments with $\rm{zELDA}$ </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Mandhai%2C+S">S. Mandhai</a>, <a href="/search/astro-ph?searchtype=author&query=Lamb%2C+G+P">G. P. Lamb</a>, <a href="/search/astro-ph?searchtype=author&query=Tanvir%2C+N+R">N. R. Tanvir</a>, <a href="/search/astro-ph?searchtype=author&query=Bray%2C+J">J. Bray</a>, <a href="/search/astro-ph?searchtype=author&query=Nixon%2C+C+J">C. J. Nixon</a>, <a href="/search/astro-ph?searchtype=author&query=Eyles-Ferris%2C+R+A+J">R. A. J. Eyles-Ferris</a>, <a href="/search/astro-ph?searchtype=author&query=Levan%2C+A+J">A. J. Levan</a>, <a href="/search/astro-ph?searchtype=author&query=Gompertz%2C+B+P">B. P. Gompertz</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2109.09714v2-abstract-short" style="display: inline;"> Compact binaries such as double neutron stars or a neutron star paired with a black-hole, are strong sources of gravitational waves during coalescence and also the likely progenitors of various electromagnetic phenomena, notably short-duration gamma-ray bursts (SGRBs), and kilonovae. In this work, we generate populations of synthetic binaries and place them in galaxies from the large-scale hydrody… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2109.09714v2-abstract-full').style.display = 'inline'; document.getElementById('2109.09714v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2109.09714v2-abstract-full" style="display: none;"> Compact binaries such as double neutron stars or a neutron star paired with a black-hole, are strong sources of gravitational waves during coalescence and also the likely progenitors of various electromagnetic phenomena, notably short-duration gamma-ray bursts (SGRBs), and kilonovae. In this work, we generate populations of synthetic binaries and place them in galaxies from the large-scale hydrodynamical galaxy evolution simulation EAGLE. With our zELDA code, binaries are seeded in proportion to star formation rate, and we follow their evolution to merger using both the BPASS and COSMIC binary stellar evolution codes. We track their dynamical evolution within their host galaxy potential, to estimate the galactocentric distance at the time of the merger. Finally, we apply observational selection criteria to allow comparison of this model population with the legacy sample of SGRBs. We find a reasonable agreement with the redshift distribution (peaking at $0.5<z<1$), host morphologies and projected galactocentric offsets (modal impact parameter $\lesssim10$ kpc). Depending on the binary simulation used, we predict $\sim16-35\%$ of SGRB events would appear "host-less", i.e. sources that merge with high impact parameters or have hosts fainter than the detection limit ($H>26$). <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2109.09714v2-abstract-full').style.display = 'none'; document.getElementById('2109.09714v2-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 June, 2022; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 20 September, 2021; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> September 2021. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">Accepted for publication in MNRAS, 21 Pages (6 Tables, 14 Figures), 14 Pages Appendix (4 Tables, 16 Figures)</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Monthly Notices of the Royal Astronomical Society, Volume 514, Issue 2, August 2022, Pages 2716-2735 </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2108.11802">arXiv:2108.11802</a> <span> [<a href="https://arxiv.org/pdf/2108.11802">pdf</a>, <a href="https://arxiv.org/format/2108.11802">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/stab2499">10.1093/mnras/stab2499 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Searching For Fermi GRB Optical Counterparts With The Prototype Gravitational-Wave Optical Transient Observer (GOTO) </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Mong%2C+Y+-">Y. -L. Mong</a>, <a href="/search/astro-ph?searchtype=author&query=Ackley%2C+K">K. Ackley</a>, <a href="/search/astro-ph?searchtype=author&query=Galloway%2C+D+K">D. K. Galloway</a>, <a href="/search/astro-ph?searchtype=author&query=Dyer%2C+M">M. Dyer</a>, <a href="/search/astro-ph?searchtype=author&query=Cutter%2C+R">R. Cutter</a>, <a href="/search/astro-ph?searchtype=author&query=Brown%2C+M+J+I">M. J. I. Brown</a>, <a href="/search/astro-ph?searchtype=author&query=Lyman%2C+J">J. Lyman</a>, <a href="/search/astro-ph?searchtype=author&query=Ulaczyk%2C+K">K. Ulaczyk</a>, <a href="/search/astro-ph?searchtype=author&query=Steeghs%2C+D">D. Steeghs</a>, <a href="/search/astro-ph?searchtype=author&query=Dhillon%2C+V">V. Dhillon</a>, <a href="/search/astro-ph?searchtype=author&query=OBrien%2C+P">P. OBrien</a>, <a href="/search/astro-ph?searchtype=author&query=Ramsay%2C+G">G. Ramsay</a>, <a href="/search/astro-ph?searchtype=author&query=Noysena%2C+K">K. Noysena</a>, <a href="/search/astro-ph?searchtype=author&query=Kotak%2C+R">R. Kotak</a>, <a href="/search/astro-ph?searchtype=author&query=Breton%2C+R">R. Breton</a>, <a href="/search/astro-ph?searchtype=author&query=Nuttall%2C+L">L. Nuttall</a>, <a href="/search/astro-ph?searchtype=author&query=Palle%2C+E">E. Palle</a>, <a href="/search/astro-ph?searchtype=author&query=Pollacco%2C+D">D. Pollacco</a>, <a href="/search/astro-ph?searchtype=author&query=Thrane%2C+E">E. Thrane</a>, <a href="/search/astro-ph?searchtype=author&query=Awiphan%2C+S">S. Awiphan</a>, <a href="/search/astro-ph?searchtype=author&query=Burhanudin%2C+U">U. Burhanudin</a>, <a href="/search/astro-ph?searchtype=author&query=Chote%2C+P">P. Chote</a>, <a href="/search/astro-ph?searchtype=author&query=Chrimes%2C+A">A. Chrimes</a>, <a href="/search/astro-ph?searchtype=author&query=Daw%2C+E">E. Daw</a>, <a href="/search/astro-ph?searchtype=author&query=Duffy%2C+C">C. Duffy</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="2108.11802v1-abstract-short" style="display: inline;"> The typical detection rate of $\sim1$ gamma-ray burst (GRB) per day by the \emph{Fermi} Gamma-ray Burst Monitor (GBM) provides a valuable opportunity to further our understanding of GRB physics. However, the large uncertainty of the \emph{Fermi} localization typically prevents rapid identification of multi-wavelength counterparts. We report the follow-up of 93 \emph{Fermi} GRBs with the Gravitatio… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2108.11802v1-abstract-full').style.display = 'inline'; document.getElementById('2108.11802v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2108.11802v1-abstract-full" style="display: none;"> The typical detection rate of $\sim1$ gamma-ray burst (GRB) per day by the \emph{Fermi} Gamma-ray Burst Monitor (GBM) provides a valuable opportunity to further our understanding of GRB physics. However, the large uncertainty of the \emph{Fermi} localization typically prevents rapid identification of multi-wavelength counterparts. We report the follow-up of 93 \emph{Fermi} GRBs with the Gravitational-wave Optical Transient Observer (GOTO) prototype on La Palma. We selected 53 events (based on favourable observing conditions) for detailed analysis, and to demonstrate our strategy of searching for optical counterparts. We apply a filtering process consisting of both automated and manual steps to 60\,085 candidates initially, rejecting all but 29, arising from 15 events. With $\approx3$ GRB afterglows expected to be detectable with GOTO from our sample, most of the candidates are unlikely to be related to the GRBs. Since we did not have multiple observations for those candidates, we cannot confidently confirm the association between the transients and the GRBs. Our results show that GOTO can effectively search for GRB optical counterparts thanks to its large field of view of $\approx40$ square degrees and its depth of $\approx20$ mag. We also detail several methods to improve our overall performance for future follow-up programs of \emph{Fermi} GRBs. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2108.11802v1-abstract-full').style.display = 'none'; document.getElementById('2108.11802v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 26 August, 2021; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> August 2021. </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2108.10184">arXiv:2108.10184</a> <span> [<a href="https://arxiv.org/pdf/2108.10184">pdf</a>, <a href="https://arxiv.org/format/2108.10184">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/10.1093/mnras/stac029">10.1093/mnras/stac029 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Constraints on compact binary merger evolution from spin-orbit misalignment in gravitational-wave observations </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Gompertz%2C+B+P">B. P. Gompertz</a>, <a href="/search/astro-ph?searchtype=author&query=Nicholl%2C+M">M. Nicholl</a>, <a href="/search/astro-ph?searchtype=author&query=Schmidt%2C+P">P. Schmidt</a>, <a href="/search/astro-ph?searchtype=author&query=Pratten%2C+G">G. Pratten</a>, <a href="/search/astro-ph?searchtype=author&query=Vecchio%2C+A">A. Vecchio</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="2108.10184v2-abstract-short" style="display: inline;"> The identification of the first confirmed neutron star - black hole (NS-BH) binary mergers by the LIGO, Virgo and KAGRA collaboration provides the opportunity to investigate the properties of the early sample of confirmed and candidate events. Here, we focus primarily on the tilt angle of the black hole's spin relative to the orbital angular momentum vector of the binary, and the implications for… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2108.10184v2-abstract-full').style.display = 'inline'; document.getElementById('2108.10184v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2108.10184v2-abstract-full" style="display: none;"> The identification of the first confirmed neutron star - black hole (NS-BH) binary mergers by the LIGO, Virgo and KAGRA collaboration provides the opportunity to investigate the properties of the early sample of confirmed and candidate events. Here, we focus primarily on the tilt angle of the black hole's spin relative to the orbital angular momentum vector of the binary, and the implications for the physical processes that determine this tilt. The posterior tilt distributions of GW200115 and the candidate events GW190426_152155 and GW190917_114630 peak at significantly anti-aligned orientations (though display wide distributions). Producing these tilts through isolated binary evolution would require stronger natal kicks than are typically considered (and preferentially-polar kicks would be ruled out), and/or an additional source of tilt such as stable mass transfer. The early sample of NS-BH events are less massive than expected for classical formation channels, and may provide evidence for efficient mass transfer that results in the merger of more massive NS-BH binaries before their evolution to the compact phase is complete. We predict that future gravitational-wave detections of NS-BH events will continue to display total binary masses of $\approx 7$ M$_{\odot}$ and mass ratios of $q \sim 3$ if this interpretation is correct. Conversely, the high mass of the candidate GW191219_163120 suggests a dynamical capture origin. Large tilts in a significant fraction of merging NS-BH systems would weaken the prospects for electromagnetic detection. However, EM observations, including non-detections, can significantly tighten the constraints on spin and mass ratio. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2108.10184v2-abstract-full').style.display = 'none'; document.getElementById('2108.10184v2-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 January, 2022; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 23 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">8 pages, 3 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/2105.11169">arXiv:2105.11169</a> <span> [<a href="https://arxiv.org/pdf/2105.11169">pdf</a>, <a href="https://arxiv.org/format/2105.11169">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/stab1545">10.1093/mnras/stab1545 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Light curve classification with recurrent neural networks for GOTO: dealing with imbalanced data </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Burhanudin%2C+U+F">U. F. Burhanudin</a>, <a href="/search/astro-ph?searchtype=author&query=Maund%2C+J+R">J. R. Maund</a>, <a href="/search/astro-ph?searchtype=author&query=Killestein%2C+T">T. Killestein</a>, <a href="/search/astro-ph?searchtype=author&query=Ackley%2C+K">K. Ackley</a>, <a href="/search/astro-ph?searchtype=author&query=Dyer%2C+M+J">M. J. Dyer</a>, <a href="/search/astro-ph?searchtype=author&query=Lyman%2C+J">J. Lyman</a>, <a href="/search/astro-ph?searchtype=author&query=Ulaczyk%2C+K">K. Ulaczyk</a>, <a href="/search/astro-ph?searchtype=author&query=Cutter%2C+R">R. Cutter</a>, <a href="/search/astro-ph?searchtype=author&query=Mong%2C+Y+-">Y. -L. Mong</a>, <a href="/search/astro-ph?searchtype=author&query=Steeghs%2C+D">D. Steeghs</a>, <a href="/search/astro-ph?searchtype=author&query=Galloway%2C+D+K">D. K. Galloway</a>, <a href="/search/astro-ph?searchtype=author&query=Dhillon%2C+V">V. Dhillon</a>, <a href="/search/astro-ph?searchtype=author&query=O%27Brien%2C+P">P. O'Brien</a>, <a href="/search/astro-ph?searchtype=author&query=Ramsay%2C+G">G. Ramsay</a>, <a href="/search/astro-ph?searchtype=author&query=Noysena%2C+K">K. Noysena</a>, <a href="/search/astro-ph?searchtype=author&query=Kotak%2C+R">R. Kotak</a>, <a href="/search/astro-ph?searchtype=author&query=Breton%2C+R+P">R. P. Breton</a>, <a href="/search/astro-ph?searchtype=author&query=Nuttall%2C+L">L. Nuttall</a>, <a href="/search/astro-ph?searchtype=author&query=Pall%C3%A9%2C+E">E. Pall茅</a>, <a href="/search/astro-ph?searchtype=author&query=Pollacco%2C+D">D. Pollacco</a>, <a href="/search/astro-ph?searchtype=author&query=Thrane%2C+E">E. Thrane</a>, <a href="/search/astro-ph?searchtype=author&query=Awiphan%2C+S">S. Awiphan</a>, <a href="/search/astro-ph?searchtype=author&query=Chote%2C+P">P. Chote</a>, <a href="/search/astro-ph?searchtype=author&query=Chrimes%2C+A">A. Chrimes</a>, <a href="/search/astro-ph?searchtype=author&query=Daw%2C+E">E. Daw</a> , et al. (20 additional authors not shown) </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2105.11169v2-abstract-short" style="display: inline;"> The advent of wide-field sky surveys has led to the growth of transient and variable source discoveries. The data deluge produced by these surveys has necessitated the use of machine learning (ML) and deep learning (DL) algorithms to sift through the vast incoming data stream. A problem that arises in real-world applications of learning algorithms for classification is imbalanced data, where a cla… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2105.11169v2-abstract-full').style.display = 'inline'; document.getElementById('2105.11169v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2105.11169v2-abstract-full" style="display: none;"> The advent of wide-field sky surveys has led to the growth of transient and variable source discoveries. The data deluge produced by these surveys has necessitated the use of machine learning (ML) and deep learning (DL) algorithms to sift through the vast incoming data stream. A problem that arises in real-world applications of learning algorithms for classification is imbalanced data, where a class of objects within the data is underrepresented, leading to a bias for over-represented classes in the ML and DL classifiers. We present a recurrent neural network (RNN) classifier that takes in photometric time-series data and additional contextual information (such as distance to nearby galaxies and on-sky position) to produce real-time classification of objects observed by the Gravitational-wave Optical Transient Observer (GOTO), and use an algorithm-level approach for handling imbalance with a focal loss function. The classifier is able to achieve an Area Under the Curve (AUC) score of 0.972 when using all available photometric observations to classify variable stars, supernovae, and active galactic nuclei. The RNN architecture allows us to classify incomplete light curves, and measure how performance improves as more observations are included. We also investigate the role that contextual information plays in producing reliable object classification. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2105.11169v2-abstract-full').style.display = 'none'; document.getElementById('2105.11169v2-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 25 May, 2021; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 24 May, 2021; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> May 2021. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">16 pages, 12 figures, to be published 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/2105.05128">arXiv:2105.05128</a> <span> [<a href="https://arxiv.org/pdf/2105.05128">pdf</a>, <a href="https://arxiv.org/format/2105.05128">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/10.1017/pasa.2021.19">10.1017/pasa.2021.19 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Processing GOTO data with the Rubin Observatory LSST Science Pipelines II: Forced Photometry and light curves </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Makrygianni%2C+L">L. Makrygianni</a>, <a href="/search/astro-ph?searchtype=author&query=Mullaney%2C+J">J. Mullaney</a>, <a href="/search/astro-ph?searchtype=author&query=Dhillon%2C+V">V. Dhillon</a>, <a href="/search/astro-ph?searchtype=author&query=Littlefair%2C+S">S. Littlefair</a>, <a href="/search/astro-ph?searchtype=author&query=Ackley%2C+K">K. Ackley</a>, <a href="/search/astro-ph?searchtype=author&query=Dyer%2C+M+J">M. J. Dyer</a>, <a href="/search/astro-ph?searchtype=author&query=Lyman%2C+J">J. Lyman</a>, <a href="/search/astro-ph?searchtype=author&query=Ulaczyk%2C+K">K. Ulaczyk</a>, <a href="/search/astro-ph?searchtype=author&query=Cutter%2C+R">R. Cutter</a>, <a href="/search/astro-ph?searchtype=author&query=Mong%2C+Y+-">Y. -L. Mong</a>, <a href="/search/astro-ph?searchtype=author&query=Steeghs%2C+D">D. Steeghs</a>, <a href="/search/astro-ph?searchtype=author&query=Galloway%2C+D+K">D. K. Galloway</a>, <a href="/search/astro-ph?searchtype=author&query=O%27Brien%2C+P">P. O'Brien</a>, <a href="/search/astro-ph?searchtype=author&query=Ramsay%2C+G">G. Ramsay</a>, <a href="/search/astro-ph?searchtype=author&query=Poshyachinda%2C+S">S. Poshyachinda</a>, <a href="/search/astro-ph?searchtype=author&query=Kotak%2C+R">R. Kotak</a>, <a href="/search/astro-ph?searchtype=author&query=Nuttall%2C+L">L. Nuttall</a>, <a href="/search/astro-ph?searchtype=author&query=Pall%C3%A9%2C+E">E. Pall茅</a>, <a href="/search/astro-ph?searchtype=author&query=Pollacco%2C+D">D. Pollacco</a>, <a href="/search/astro-ph?searchtype=author&query=Thrane%2C+E">E. Thrane</a>, <a href="/search/astro-ph?searchtype=author&query=Aukkaravittayapun%2C+S">S. Aukkaravittayapun</a>, <a href="/search/astro-ph?searchtype=author&query=Awiphan%2C+S">S. Awiphan</a>, <a href="/search/astro-ph?searchtype=author&query=Breton%2C+R">R. Breton</a>, <a href="/search/astro-ph?searchtype=author&query=Burhanudin%2C+U">U. Burhanudin</a>, <a href="/search/astro-ph?searchtype=author&query=Chote%2C+P">P. Chote</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="2105.05128v1-abstract-short" style="display: inline;"> We have adapted the Vera C. Rubin Observatory Legacy Survey of Space and Time (LSST) Science Pipelines to process data from the Gravitational-Wave Optical Transient Observer (GOTO) prototype. In this paper, we describe how we used the Rubin Observatory LSST Science Pipelines to conduct forced photometry measurements on nightly GOTO data. By comparing the photometry measurements of sources taken on… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2105.05128v1-abstract-full').style.display = 'inline'; document.getElementById('2105.05128v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2105.05128v1-abstract-full" style="display: none;"> We have adapted the Vera C. Rubin Observatory Legacy Survey of Space and Time (LSST) Science Pipelines to process data from the Gravitational-Wave Optical Transient Observer (GOTO) prototype. In this paper, we describe how we used the Rubin Observatory LSST Science Pipelines to conduct forced photometry measurements on nightly GOTO data. By comparing the photometry measurements of sources taken on multiple nights, we find that the precision of our photometry is typically better than 20~mmag for sources brighter than 16 mag. We also compare our photometry measurements against colour-corrected PanSTARRS photometry, and find that the two agree to within 10~mmag (1$蟽$) for bright (i.e., $\sim14^{\rm th}$~mag) sources to 200~mmag for faint (i.e., $\sim18^{\rm th}$~mag) sources. Additionally, we compare our results to those obtained by GOTO's own in-house pipeline, {\sc gotophoto}, and obtain similar results. Based on repeatability measurements, we measure a $5蟽$ L-band survey depth of between 19 and 20 magnitudes, depending on observing conditions. We assess, using repeated observations of non-varying standard SDSS stars, the accuracy of our uncertainties, which we find are typically overestimated by roughly a factor of two for bright sources (i.e., $<15^{\rm th}$~mag), but slightly underestimated (by roughly a factor of 1.25) for fainter sources ($>17^{\rm th}$~mag). Finally, we present lightcurves for a selection of variable sources, and compare them to those obtained with the Zwicky Transient Factory and GAIA. Despite the Rubin Observatory LSST Science Pipelines still undergoing active development, our results show that they are already delivering robust forced photometry measurements from GOTO data. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2105.05128v1-abstract-full').style.display = 'none'; document.getElementById('2105.05128v1-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, 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 for publication in PASA</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2102.09892">arXiv:2102.09892</a> <span> [<a href="https://arxiv.org/pdf/2102.09892">pdf</a>, <a href="https://arxiv.org/format/2102.09892">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/stab633">10.1093/mnras/stab633 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Transient-optimised real-bogus classification with Bayesian Convolutional Neural Networks -- sifting the GOTO candidate stream </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Killestein%2C+T+L">T. L. Killestein</a>, <a href="/search/astro-ph?searchtype=author&query=Lyman%2C+J">J. Lyman</a>, <a href="/search/astro-ph?searchtype=author&query=Steeghs%2C+D">D. Steeghs</a>, <a href="/search/astro-ph?searchtype=author&query=Ackley%2C+K">K. Ackley</a>, <a href="/search/astro-ph?searchtype=author&query=Dyer%2C+M+J">M. J. Dyer</a>, <a href="/search/astro-ph?searchtype=author&query=Ulaczyk%2C+K">K. Ulaczyk</a>, <a href="/search/astro-ph?searchtype=author&query=Cutter%2C+R">R. Cutter</a>, <a href="/search/astro-ph?searchtype=author&query=Mong%2C+Y+-">Y. -L. Mong</a>, <a href="/search/astro-ph?searchtype=author&query=Galloway%2C+D+K">D. K. Galloway</a>, <a href="/search/astro-ph?searchtype=author&query=Dhillon%2C+V">V. Dhillon</a>, <a href="/search/astro-ph?searchtype=author&query=O%27Brien%2C+P">P. O'Brien</a>, <a href="/search/astro-ph?searchtype=author&query=Ramsay%2C+G">G. Ramsay</a>, <a href="/search/astro-ph?searchtype=author&query=Poshyachinda%2C+S">S. Poshyachinda</a>, <a href="/search/astro-ph?searchtype=author&query=Kotak%2C+R">R. Kotak</a>, <a href="/search/astro-ph?searchtype=author&query=Breton%2C+R+P">R. P. Breton</a>, <a href="/search/astro-ph?searchtype=author&query=Nuttall%2C+L+K">L. K. Nuttall</a>, <a href="/search/astro-ph?searchtype=author&query=Pall%C3%A9%2C+E">E. Pall茅</a>, <a href="/search/astro-ph?searchtype=author&query=Pollacco%2C+D">D. Pollacco</a>, <a href="/search/astro-ph?searchtype=author&query=Thrane%2C+E">E. Thrane</a>, <a href="/search/astro-ph?searchtype=author&query=Aukkaravittayapun%2C+S">S. Aukkaravittayapun</a>, <a href="/search/astro-ph?searchtype=author&query=Awiphan%2C+S">S. Awiphan</a>, <a href="/search/astro-ph?searchtype=author&query=Burhanudin%2C+U">U. Burhanudin</a>, <a href="/search/astro-ph?searchtype=author&query=Chote%2C+P">P. Chote</a>, <a href="/search/astro-ph?searchtype=author&query=Chrimes%2C+A">A. Chrimes</a>, <a href="/search/astro-ph?searchtype=author&query=Daw%2C+E">E. Daw</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="2102.09892v1-abstract-short" style="display: inline;"> Large-scale sky surveys have played a transformative role in our understanding of astrophysical transients, only made possible by increasingly powerful machine learning-based filtering to accurately sift through the vast quantities of incoming data generated. In this paper, we present a new real-bogus classifier based on a Bayesian convolutional neural network that provides nuanced, uncertainty-aw… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2102.09892v1-abstract-full').style.display = 'inline'; document.getElementById('2102.09892v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2102.09892v1-abstract-full" style="display: none;"> Large-scale sky surveys have played a transformative role in our understanding of astrophysical transients, only made possible by increasingly powerful machine learning-based filtering to accurately sift through the vast quantities of incoming data generated. In this paper, we present a new real-bogus classifier based on a Bayesian convolutional neural network that provides nuanced, uncertainty-aware classification of transient candidates in difference imaging, and demonstrate its application to the datastream from the GOTO wide-field optical survey. Not only are candidates assigned a well-calibrated probability of being real, but also an associated confidence that can be used to prioritise human vetting efforts and inform future model optimisation via active learning. To fully realise the potential of this architecture, we present a fully-automated training set generation method which requires no human labelling, incorporating a novel data-driven augmentation method to significantly improve the recovery of faint and nuclear transient sources. We achieve competitive classification accuracy (FPR and FNR both below 1%) compared against classifiers trained with fully human-labelled datasets, whilst being significantly quicker and less labour-intensive to build. This data-driven approach is uniquely scalable to the upcoming challenges and data needs of next-generation transient surveys. We make our data generation and model training codes available to the community. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2102.09892v1-abstract-full').style.display = 'none'; document.getElementById('2102.09892v1-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, 2021; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> February 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">17 pages, 12 figures, resubmitted to MNRAS following reviewer comments</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2010.15142">arXiv:2010.15142</a> <span> [<a href="https://arxiv.org/pdf/2010.15142">pdf</a>, <a href="https://arxiv.org/format/2010.15142">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/10.1017/pasa.2020.45">10.1017/pasa.2020.45 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Processing GOTO data with the Rubin Observatory LSST Science Pipelines I : Production of coadded frames </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Mullaney%2C+J+R">J. R. Mullaney</a>, <a href="/search/astro-ph?searchtype=author&query=Makrygianni%2C+L">L. Makrygianni</a>, <a href="/search/astro-ph?searchtype=author&query=Dhillon%2C+V">V. Dhillon</a>, <a href="/search/astro-ph?searchtype=author&query=Littlefair%2C+S">S. Littlefair</a>, <a href="/search/astro-ph?searchtype=author&query=Ackley%2C+K">K. Ackley</a>, <a href="/search/astro-ph?searchtype=author&query=Dyer%2C+M">M. Dyer</a>, <a href="/search/astro-ph?searchtype=author&query=Lyman%2C+J">J. Lyman</a>, <a href="/search/astro-ph?searchtype=author&query=Ulaczyk%2C+K">K. Ulaczyk</a>, <a href="/search/astro-ph?searchtype=author&query=Cutter%2C+R">R. Cutter</a>, <a href="/search/astro-ph?searchtype=author&query=Mong%2C+Y+L">Y. L. Mong</a>, <a href="/search/astro-ph?searchtype=author&query=Steeghs%2C+D">D. Steeghs</a>, <a href="/search/astro-ph?searchtype=author&query=Galloway%2C+D+K">D. K. Galloway</a>, <a href="/search/astro-ph?searchtype=author&query=O%27Brien%2C+P">P. O'Brien</a>, <a href="/search/astro-ph?searchtype=author&query=Ramsay%2C+G">G. Ramsay</a>, <a href="/search/astro-ph?searchtype=author&query=Poshyachinda%2C+S">S. Poshyachinda</a>, <a href="/search/astro-ph?searchtype=author&query=Kotak%2C+R">R. Kotak</a>, <a href="/search/astro-ph?searchtype=author&query=Nuttall%2C+L">L. Nuttall</a>, <a href="/search/astro-ph?searchtype=author&query=Pall%C3%A9%2C+E">E. Pall茅</a>, <a href="/search/astro-ph?searchtype=author&query=Pollacco%2C+D">D. Pollacco</a>, <a href="/search/astro-ph?searchtype=author&query=Thrane%2C+E">E. Thrane</a>, <a href="/search/astro-ph?searchtype=author&query=Aukkaravittayapun%2C+S">S. Aukkaravittayapun</a>, <a href="/search/astro-ph?searchtype=author&query=Awiphan%2C+S">S. Awiphan</a>, <a href="/search/astro-ph?searchtype=author&query=Breton%2C+R">R. Breton</a>, <a href="/search/astro-ph?searchtype=author&query=Burhanudin%2C+U">U. Burhanudin</a>, <a href="/search/astro-ph?searchtype=author&query=Chote%2C+P">P. Chote</a> , et al. (22 additional authors not shown) </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2010.15142v1-abstract-short" style="display: inline;"> The past few decades have seen the burgeoning of wide field, high cadence surveys, the most formidable of which will be the Legacy Survey of Space and Time (LSST) to be conducted by the Vera C. Rubin Observatory. So new is the field of systematic time-domain survey astronomy, however, that major scientific insights will continue to be obtained using smaller, more flexible systems than the LSST. On… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2010.15142v1-abstract-full').style.display = 'inline'; document.getElementById('2010.15142v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2010.15142v1-abstract-full" style="display: none;"> The past few decades have seen the burgeoning of wide field, high cadence surveys, the most formidable of which will be the Legacy Survey of Space and Time (LSST) to be conducted by the Vera C. Rubin Observatory. So new is the field of systematic time-domain survey astronomy, however, that major scientific insights will continue to be obtained using smaller, more flexible systems than the LSST. One such example is the Gravitational-wave Optical Transient Observer (GOTO), whose primary science objective is the optical follow-up of Gravitational Wave events. The amount and rate of data production by GOTO and other wide-area, high-cadence surveys presents a significant challenge to data processing pipelines which need to operate in near real-time to fully exploit the time-domain. In this study, we adapt the Rubin Observatory LSST Science Pipelines to process GOTO data, thereby exploring the feasibility of using this "off-the-shelf" pipeline to process data from other wide-area, high-cadence surveys. In this paper, we describe how we use the LSST Science Pipelines to process raw GOTO frames to ultimately produce calibrated coadded images and photometric source catalogues. After comparing the measured astrometry and photometry to those of matched sources from PanSTARRS DR1, we find that measured source positions are typically accurate to sub-pixel levels, and that measured L-band photometries are accurate to $\sim50$ mmag at $m_L\sim16$ and $\sim200$ mmag at $m_L\sim18$. These values compare favourably to those obtained using GOTO's primary, in-house pipeline, GOTOPHOTO, in spite of both pipelines having undergone further development and improvement beyond the implementations used in this study. Finally, we release a generic "obs package" that others can build-upon should they wish to use the LSST Science Pipelines to process data from other facilities. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2010.15142v1-abstract-full').style.display = 'none'; document.getElementById('2010.15142v1-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 October, 2020; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> October 2020. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">17 pages, 13 figures. Accepted for publication in PASA</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2008.10178">arXiv:2008.10178</a> <span> [<a href="https://arxiv.org/pdf/2008.10178">pdf</a>, <a href="https://arxiv.org/format/2008.10178">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/staa3096">10.1093/mnras/staa3096 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Machine Learning for Transient Recognition in Difference Imaging With Minimum Sampling Effort </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Mong%2C+Y">Yik-Lun Mong</a>, <a href="/search/astro-ph?searchtype=author&query=Ackley%2C+K">Kendall Ackley</a>, <a href="/search/astro-ph?searchtype=author&query=Galloway%2C+D">Duncan Galloway</a>, <a href="/search/astro-ph?searchtype=author&query=Killestein%2C+T">Tom Killestein</a>, <a href="/search/astro-ph?searchtype=author&query=Lyman%2C+J">Joe Lyman</a>, <a href="/search/astro-ph?searchtype=author&query=Steeghs%2C+D">Danny Steeghs</a>, <a href="/search/astro-ph?searchtype=author&query=Dhillon%2C+V">Vik Dhillon</a>, <a href="/search/astro-ph?searchtype=author&query=O%27Brien%2C+P">Paul O'Brien</a>, <a href="/search/astro-ph?searchtype=author&query=Ramsay%2C+G">Gavin Ramsay</a>, <a href="/search/astro-ph?searchtype=author&query=Poshyachinda%2C+S">Saran Poshyachinda</a>, <a href="/search/astro-ph?searchtype=author&query=Kotak%2C+R">Rubina Kotak</a>, <a href="/search/astro-ph?searchtype=author&query=Nuttall%2C+L">Laura Nuttall</a>, <a href="/search/astro-ph?searchtype=author&query=Pall%27e%2C+E">Enric Pall'e</a>, <a href="/search/astro-ph?searchtype=author&query=Pollacco%2C+D">Don Pollacco</a>, <a href="/search/astro-ph?searchtype=author&query=Thrane%2C+E">Eric Thrane</a>, <a href="/search/astro-ph?searchtype=author&query=Dyer%2C+M">Martin Dyer</a>, <a href="/search/astro-ph?searchtype=author&query=Ulaczyk%2C+K">Krzysztof Ulaczyk</a>, <a href="/search/astro-ph?searchtype=author&query=Cutter%2C+R">Ryan Cutter</a>, <a href="/search/astro-ph?searchtype=author&query=McCormac%2C+J">James McCormac</a>, <a href="/search/astro-ph?searchtype=author&query=Chote%2C+P">Paul Chote</a>, <a href="/search/astro-ph?searchtype=author&query=Levan%2C+A">Andrew Levan</a>, <a href="/search/astro-ph?searchtype=author&query=Marsh%2C+T">Tom Marsh</a>, <a href="/search/astro-ph?searchtype=author&query=Stanway%2C+E">Elizabeth Stanway</a>, <a href="/search/astro-ph?searchtype=author&query=Gompertz%2C+B">Ben Gompertz</a>, <a href="/search/astro-ph?searchtype=author&query=Wiersema%2C+K">Klaas Wiersema</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="2008.10178v2-abstract-short" style="display: inline;"> The amount of observational data produced by time-domain astronomy is exponentially in-creasing. Human inspection alone is not an effective way to identify genuine transients fromthe data. An automatic real-bogus classifier is needed and machine learning techniques are commonly used to achieve this goal. Building a training set with a sufficiently large number of verified transients is challenging… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2008.10178v2-abstract-full').style.display = 'inline'; document.getElementById('2008.10178v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2008.10178v2-abstract-full" style="display: none;"> The amount of observational data produced by time-domain astronomy is exponentially in-creasing. Human inspection alone is not an effective way to identify genuine transients fromthe data. An automatic real-bogus classifier is needed and machine learning techniques are commonly used to achieve this goal. Building a training set with a sufficiently large number of verified transients is challenging, due to the requirement of human verification. We presentan approach for creating a training set by using all detections in the science images to be thesample of real detections and all detections in the difference images, which are generated by the process of difference imaging to detect transients, to be the samples of bogus detections. This strategy effectively minimizes the labour involved in the data labelling for supervised machine learning methods. We demonstrate the utility of the training set by using it to train several classifiers utilizing as the feature representation the normalized pixel values in 21-by-21pixel stamps centered at the detection position, observed with the Gravitational-wave Optical Transient Observer (GOTO) prototype. The real-bogus classifier trained with this strategy can provide up to 95% prediction accuracy on the real detections at a false alarm rate of 1%. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2008.10178v2-abstract-full').style.display = 'none'; document.getElementById('2008.10178v2-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 October, 2020; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 23 August, 2020; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> August 2020. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">9 pages, 8 figures</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2004.00025">arXiv:2004.00025</a> <span> [<a href="https://arxiv.org/pdf/2004.00025">pdf</a>, <a href="https://arxiv.org/format/2004.00025">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/staa1845">10.1093/mnras/staa1845 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Searching for Electromagnetic Counterparts to Gravitational-wave Merger Events with the Prototype Gravitational-wave Optical Transient Observer (GOTO-4) </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Gompertz%2C+B+P">B. P. Gompertz</a>, <a href="/search/astro-ph?searchtype=author&query=Cutter%2C+R">R. Cutter</a>, <a href="/search/astro-ph?searchtype=author&query=Steeghs%2C+D">D. Steeghs</a>, <a href="/search/astro-ph?searchtype=author&query=Galloway%2C+D+K">D. K. Galloway</a>, <a href="/search/astro-ph?searchtype=author&query=Lyman%2C+J">J. Lyman</a>, <a href="/search/astro-ph?searchtype=author&query=Ulaczyk%2C+K">K. Ulaczyk</a>, <a href="/search/astro-ph?searchtype=author&query=Dyer%2C+M+J">M. J. Dyer</a>, <a href="/search/astro-ph?searchtype=author&query=Ackley%2C+K">K. Ackley</a>, <a href="/search/astro-ph?searchtype=author&query=Dhillon%2C+V+S">V. S. Dhillon</a>, <a href="/search/astro-ph?searchtype=author&query=O%27Brien%2C+P+T">P. T. O'Brien</a>, <a href="/search/astro-ph?searchtype=author&query=Ramsay%2C+G">G. Ramsay</a>, <a href="/search/astro-ph?searchtype=author&query=Poshyachinda%2C+S">S. Poshyachinda</a>, <a href="/search/astro-ph?searchtype=author&query=Kotak%2C+R">R. Kotak</a>, <a href="/search/astro-ph?searchtype=author&query=Nuttall%2C+L">L. Nuttall</a>, <a href="/search/astro-ph?searchtype=author&query=Breton%2C+R+P">R. P. Breton</a>, <a href="/search/astro-ph?searchtype=author&query=Pall%C3%A9%2C+E">E. Pall茅</a>, <a href="/search/astro-ph?searchtype=author&query=Pollacco%2C+D">D. Pollacco</a>, <a href="/search/astro-ph?searchtype=author&query=Thrane%2C+E">E. Thrane</a>, <a href="/search/astro-ph?searchtype=author&query=Aukkaravittayapun%2C+S">S. Aukkaravittayapun</a>, <a href="/search/astro-ph?searchtype=author&query=Awiphan%2C+S">S. Awiphan</a>, <a href="/search/astro-ph?searchtype=author&query=Brown%2C+M+J+I">M. J. I. Brown</a>, <a href="/search/astro-ph?searchtype=author&query=Burhanudin%2C+U">U. Burhanudin</a>, <a href="/search/astro-ph?searchtype=author&query=Chote%2C+P">P. Chote</a>, <a href="/search/astro-ph?searchtype=author&query=Chrimes%2C+A+A">A. A. Chrimes</a>, <a href="/search/astro-ph?searchtype=author&query=Daw%2C+E">E. Daw</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="2004.00025v2-abstract-short" style="display: inline;"> We report the results of optical follow-up observations of 29 gravitational-wave triggers during the first half of the LIGO-Virgo Collaboration (LVC) O3 run with the Gravitational-wave Optical Transient Observer (GOTO) in its prototype 4-telescope configuration (GOTO-4). While no viable electromagnetic counterpart candidate was identified, we estimate our 3D (volumetric) coverage using test light… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2004.00025v2-abstract-full').style.display = 'inline'; document.getElementById('2004.00025v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2004.00025v2-abstract-full" style="display: none;"> We report the results of optical follow-up observations of 29 gravitational-wave triggers during the first half of the LIGO-Virgo Collaboration (LVC) O3 run with the Gravitational-wave Optical Transient Observer (GOTO) in its prototype 4-telescope configuration (GOTO-4). While no viable electromagnetic counterpart candidate was identified, we estimate our 3D (volumetric) coverage using test light curves of on- and off-axis gamma-ray bursts and kilonovae. In cases where the source region was observable immediately, GOTO-4 was able to respond to a GW alert in less than a minute. The average time of first observation was $8.79$ hours after receiving an alert ($9.90$ hours after trigger). A mean of $732.3$ square degrees were tiled per event, representing on average $45.3$ per cent of the LVC probability map, or $70.3$ per cent of the observable probability. This coverage will further improve as the facility scales up alongside the localisation performance of the evolving gravitational-wave detector network. Even in its 4-telescope prototype configuration, GOTO is capable of detecting AT2017gfo-like kilonovae beyond 200~Mpc in favourable observing conditions. We cannot currently place meaningful electromagnetic limits on the population of distant ($\hat{D}_L = 1.3$~Gpc) binary black hole mergers because our test models are too faint to recover at this distance. However, as GOTO is upgraded towards its full 32-telescope, 2 node (La Palma \& Australia) configuration, it is expected to be sufficiently sensitive to cover the predicted O4 binary neutron star merger volume, and will be able to respond to both northern and southern triggers. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2004.00025v2-abstract-full').style.display = 'none'; document.getElementById('2004.00025v2-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 July, 2020; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 31 March, 2020; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> April 2020. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">15 pages, 7 figures, 3 tables. Accepted for publication in MNRAS. Author's final submitted version</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2002.01950">arXiv:2002.01950</a> <span> [<a href="https://arxiv.org/pdf/2002.01950">pdf</a>, <a href="https://arxiv.org/format/2002.01950">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/10.1051/0004-6361/202037669">10.1051/0004-6361/202037669 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Observational constraints on the optical and near-infrared emission from the neutron star-black hole binary merger S190814bv </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Ackley%2C+K">K. Ackley</a>, <a href="/search/astro-ph?searchtype=author&query=Amati%2C+L">L. Amati</a>, <a href="/search/astro-ph?searchtype=author&query=Barbieri%2C+C">C. Barbieri</a>, <a href="/search/astro-ph?searchtype=author&query=Bauer%2C+F+E">F. E. Bauer</a>, <a href="/search/astro-ph?searchtype=author&query=Benetti%2C+S">S. Benetti</a>, <a href="/search/astro-ph?searchtype=author&query=Bernardini%2C+M+G">M. G. Bernardini</a>, <a href="/search/astro-ph?searchtype=author&query=Bhirombhakdi%2C+K">K. Bhirombhakdi</a>, <a href="/search/astro-ph?searchtype=author&query=Botticella%2C+M+T">M. T. Botticella</a>, <a href="/search/astro-ph?searchtype=author&query=Branchesi%2C+M">M. Branchesi</a>, <a href="/search/astro-ph?searchtype=author&query=Brocato%2C+E">E. Brocato</a>, <a href="/search/astro-ph?searchtype=author&query=Bruun%2C+S+H">S. H. Bruun</a>, <a href="/search/astro-ph?searchtype=author&query=Bulla%2C+M">M. Bulla</a>, <a href="/search/astro-ph?searchtype=author&query=Campana%2C+S">S. Campana</a>, <a href="/search/astro-ph?searchtype=author&query=Cappellaro%2C+E">E. Cappellaro</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=Chambers%2C+K+C">K. C. Chambers</a>, <a href="/search/astro-ph?searchtype=author&query=Chaty%2C+S">S. Chaty</a>, <a href="/search/astro-ph?searchtype=author&query=Chen%2C+T+-">T. -W. Chen</a>, <a href="/search/astro-ph?searchtype=author&query=Ciolfi%2C+R">R. Ciolfi</a>, <a href="/search/astro-ph?searchtype=author&query=Coleiro%2C+A">A. Coleiro</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=Covino%2C+S">S. Covino</a>, <a href="/search/astro-ph?searchtype=author&query=Cutter%2C+R">R. Cutter</a>, <a href="/search/astro-ph?searchtype=author&query=D%27Ammando%2C+F">F. D'Ammando</a>, <a href="/search/astro-ph?searchtype=author&query=D%27Avanzo%2C+P">P. D'Avanzo</a> , et al. (129 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="2002.01950v2-abstract-short" style="display: inline;"> On 2019 August 14, the LIGO and Virgo interferometers detected a high-significance event labelled S190814bv. Preliminary analysis of the GW data suggests that the event was likely due to the merger of a compact binary system formed by a BH and a NS. ElectromagNetic counterparts of GRAvitational wave sources at the VEry Large Telescope (ENGRAVE) collaboration members carried out an intensive multi-… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2002.01950v2-abstract-full').style.display = 'inline'; document.getElementById('2002.01950v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2002.01950v2-abstract-full" style="display: none;"> On 2019 August 14, the LIGO and Virgo interferometers detected a high-significance event labelled S190814bv. Preliminary analysis of the GW data suggests that the event was likely due to the merger of a compact binary system formed by a BH and a NS. ElectromagNetic counterparts of GRAvitational wave sources at the VEry Large Telescope (ENGRAVE) collaboration members carried out an intensive multi-epoch, multi-instrument observational campaign to identify the possible optical/near infrared counterpart of the event. In addition, the ATLAS, GOTO, GRAWITA-VST, Pan-STARRS and VINROUGE projects also carried out a search on this event. Our observations allow us to place limits on the presence of any counterpart and discuss the implications for the kilonova (KN) possibly generated by this NS-BH merger, and for the strategy of future searches. Altogether, our observations allow us to exclude a KN with large ejecta mass $M\gtrsim 0.1\,\mathrm{M_\odot}$ to a high ($>90\%$) confidence, and we can exclude much smaller masses in a subsample of our observations. This disfavours the tidal disruption of the neutron star during the merger. Despite the sensitive instruments involved in the campaign, given the distance of S190814bv we could not reach sufficiently deep limits to constrain a KN comparable in luminosity to AT 2017gfo on a large fraction of the localisation probability. This suggests that future (likely common) events at a few hundreds Mpc will be detected only by large facilities with both high sensitivity and large field of view. Galaxy-targeted observations can reach the needed depth over a relevant portion of the localisation probability with a smaller investment of resources, but the number of galaxies to be targeted in order to get a fairly complete coverage is large, even in the case of a localisation as good as that of this event. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2002.01950v2-abstract-full').style.display = 'none'; document.getElementById('2002.01950v2-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 June, 2020; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 5 February, 2020; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> February 2020. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">52 pages, revised version now accepted for publication in A&A. Abstract abridged to meet arXiv requirements</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> A&A 643, A113 (2020) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2001.08706">arXiv:2001.08706</a> <span> [<a href="https://arxiv.org/pdf/2001.08706">pdf</a>, <a href="https://arxiv.org/format/2001.08706">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/ab8d24">10.3847/1538-4357/ab8d24 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> A Search for Neutron Star-Black Hole Binary Mergers in the Short Gamma-Ray Burst Population </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Gompertz%2C+B+P">B. P. Gompertz</a>, <a href="/search/astro-ph?searchtype=author&query=Levan%2C+A+J">A. J. Levan</a>, <a href="/search/astro-ph?searchtype=author&query=Tanvir%2C+N+R">N. R. Tanvir</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="2001.08706v2-abstract-short" style="display: inline;"> Short gamma-ray bursts (SGRBs) are now known to be the product of the merger of two compact objects. However, two possible formation channels exist: neutron star -- neutron star (NS -- NS) or NS -- black hole (BH). The landmark SGRB 170817A provided evidence for the NS -- NS channel, thanks to analysis of its gravitational wave signal. We investigate the complete population of SGRBs with an associ… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2001.08706v2-abstract-full').style.display = 'inline'; document.getElementById('2001.08706v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2001.08706v2-abstract-full" style="display: none;"> Short gamma-ray bursts (SGRBs) are now known to be the product of the merger of two compact objects. However, two possible formation channels exist: neutron star -- neutron star (NS -- NS) or NS -- black hole (BH). The landmark SGRB 170817A provided evidence for the NS -- NS channel, thanks to analysis of its gravitational wave signal. We investigate the complete population of SGRBs with an associated redshift (39 events), and search for any divisions that may indicate that a NS -- BH formation channel also contributes. Though no conclusive dichotomy is found, we find several lines of evidence that tentatively support the hypothesis that SGRBs with extended emission (EE; 7 events) constitute the missing merger population: they are unique in the large energy band-sensitivity of their durations, and have statistically distinct energies and host galaxy offsets when compared to regular (non-EE) SGRBs. If this is borne out via future gravitational wave detections it will conclusively disprove the magnetar model for SGRBs. Furthermore, we identify the first statistically significant anti-correlation between the offsets of SGRBs from their host galaxies and their prompt emission energies. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2001.08706v2-abstract-full').style.display = 'none'; document.getElementById('2001.08706v2-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 7 May, 2020; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 23 January, 2020; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> January 2020. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">23 pages, 9 figures, 2 tables. 1 appendix (2 pages, 1 table). Author's final accepted version, to be published 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/1910.11624">arXiv:1910.11624</a> <span> [<a href="https://arxiv.org/pdf/1910.11624">pdf</a>, <a href="https://arxiv.org/ps/1910.11624">ps</a>, <a href="https://arxiv.org/format/1910.11624">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/stz3106">10.1093/mnras/stz3106 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Polarimetry of relativistic tidal disruption event Swift J2058+0516 </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Wiersema%2C+K">K. Wiersema</a>, <a href="/search/astro-ph?searchtype=author&query=Higgins%2C+A+B">A. B. Higgins</a>, <a href="/search/astro-ph?searchtype=author&query=Levan%2C+A+J">A. J. Levan</a>, <a href="/search/astro-ph?searchtype=author&query=Eyles%2C+R+A+J">R. A. J. Eyles</a>, <a href="/search/astro-ph?searchtype=author&query=Starling%2C+R+L+C">R. L. C. Starling</a>, <a href="/search/astro-ph?searchtype=author&query=Tanvir%2C+N+R">N. R. Tanvir</a>, <a href="/search/astro-ph?searchtype=author&query=Cenko%2C+S+B">S. B. Cenko</a>, <a href="/search/astro-ph?searchtype=author&query=van+der+Horst%2C+A+J">A. J. van der Horst</a>, <a href="/search/astro-ph?searchtype=author&query=Gompertz%2C+B+P">B. P. Gompertz</a>, <a href="/search/astro-ph?searchtype=author&query=Greiner%2C+J">J. Greiner</a>, <a href="/search/astro-ph?searchtype=author&query=Pasham%2C+D+R">D. R. Pasham</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="1910.11624v1-abstract-short" style="display: inline;"> A small fraction of candidate tidal disruption events (TDEs) show evidence of powerful relativistic jets, which are particularly pronounced at radio wavelengths, and likely contribute non-thermal emission at a wide range of wavelengths. A non-thermal emission component can be diagnosed using linear polarimetry, even when the total received light is dominated by emission from an accretion disk or d… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1910.11624v1-abstract-full').style.display = 'inline'; document.getElementById('1910.11624v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1910.11624v1-abstract-full" style="display: none;"> A small fraction of candidate tidal disruption events (TDEs) show evidence of powerful relativistic jets, which are particularly pronounced at radio wavelengths, and likely contribute non-thermal emission at a wide range of wavelengths. A non-thermal emission component can be diagnosed using linear polarimetry, even when the total received light is dominated by emission from an accretion disk or disk outflow. In this paper we present Very Large Telescope (VLT) measurements of the linear polarisation of the optical light of jetted TDE Swift J2058+0516. This is the second jetted TDE studied in this manner, after Swift J1644+57. We find evidence of non-zero optical linear polarisation, P_V ~ 8%, a level very similar to the near-infrared polarimetry of Swift J1644+57. These detections provide an independent test of the emission mechanisms of the multiwavelength emission of jetted tidal disruption events. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1910.11624v1-abstract-full').style.display = 'none'; document.getElementById('1910.11624v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 25 October, 2019; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> October 2019. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">7 pages, 4 figures, 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/1907.10091">arXiv:1907.10091</a> <span> [<a href="https://arxiv.org/pdf/1907.10091">pdf</a>, <a href="https://arxiv.org/format/1907.10091">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/stz2040">10.1093/mnras/stz2040 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> An unusual transient following the short GRB 071227 </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Eyles%2C+R+A+J">R. A. J. Eyles</a>, <a href="/search/astro-ph?searchtype=author&query=O%27Brien%2C+P+T">P. T. O'Brien</a>, <a href="/search/astro-ph?searchtype=author&query=Wiersema%2C+K">K. Wiersema</a>, <a href="/search/astro-ph?searchtype=author&query=Starling%2C+R+L+C">R. L. C. Starling</a>, <a href="/search/astro-ph?searchtype=author&query=Gompertz%2C+B+P">B. P. Gompertz</a>, <a href="/search/astro-ph?searchtype=author&query=Lamb%2C+G+P">G. P. Lamb</a>, <a href="/search/astro-ph?searchtype=author&query=Lyman%2C+J+D">J. D. Lyman</a>, <a href="/search/astro-ph?searchtype=author&query=Levan%2C+A+J">A. J. Levan</a>, <a href="/search/astro-ph?searchtype=author&query=Rosswog%2C+S">S. Rosswog</a>, <a href="/search/astro-ph?searchtype=author&query=Tanvir%2C+N+R">N. R. Tanvir</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="1907.10091v1-abstract-short" style="display: inline;"> We present X-ray and optical observations of the short duration gamma-ray burst GRB 071227 and its host at $z=0.381$, obtained using \textit{Swift}, Gemini South and the Very Large Telescope. We identify a short-lived and moderately bright optical transient, with flux significantly in excess of that expected from a simple extrapolation of the X-ray spectrum at 0.2-0.3 days after burst. We fit the… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1907.10091v1-abstract-full').style.display = 'inline'; document.getElementById('1907.10091v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1907.10091v1-abstract-full" style="display: none;"> We present X-ray and optical observations of the short duration gamma-ray burst GRB 071227 and its host at $z=0.381$, obtained using \textit{Swift}, Gemini South and the Very Large Telescope. We identify a short-lived and moderately bright optical transient, with flux significantly in excess of that expected from a simple extrapolation of the X-ray spectrum at 0.2-0.3 days after burst. We fit the SED with afterglow models allowing for high extinction and thermal emission models that approximate a kilonova to assess the excess' origins. While some kilonova contribution is plausible, it is not favoured due to the low temperature and high luminosity required, implying superluminal expansion and a large ejecta mass of $\sim 0.1$ M$_{\odot}$. We find, instead, that the transient is broadly consistent with power-law spectra with additional dust extinction of $E(B-V)\sim0.4$ mag, although a possibly thermal excess remains in the \textit{z}-band. We investigate the host, a spiral galaxy with an edge-on orientation, resolving its spectrum along its major axis to construct the galaxy rotation curve and analyse the star formation and chemical properties. The integrated host emission shows evidence for high extinction, consistent with the afterglow findings. The metallicity and extinction are consistent with previous studies of this host and indicate the galaxy is a typical, but dusty, late-type SGRB host. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1907.10091v1-abstract-full').style.display = 'none'; document.getElementById('1907.10091v1-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 July, 2019; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> July 2019. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">16 pages, 13 figures, accepted to MNRAS</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1907.00213">arXiv:1907.00213</a> <span> [<a href="https://arxiv.org/pdf/1907.00213">pdf</a>, <a href="https://arxiv.org/format/1907.00213">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/stz1811">10.1093/mnras/stz1811 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> The Case for a High-Redshift Origin of GRB100205A </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Chrimes%2C+A+A">A. A. Chrimes</a>, <a href="/search/astro-ph?searchtype=author&query=Levan%2C+A+J">A. J. Levan</a>, <a href="/search/astro-ph?searchtype=author&query=Stanway%2C+E+R">E. R. Stanway</a>, <a href="/search/astro-ph?searchtype=author&query=Berger%2C+E">E. Berger</a>, <a href="/search/astro-ph?searchtype=author&query=Bloom%2C+J+S">J. S. Bloom</a>, <a href="/search/astro-ph?searchtype=author&query=Cenko%2C+S+B">S. B. Cenko</a>, <a href="/search/astro-ph?searchtype=author&query=Cobb%2C+B+E">B. E. Cobb</a>, <a href="/search/astro-ph?searchtype=author&query=Cucchiara%2C+A">A. Cucchiara</a>, <a href="/search/astro-ph?searchtype=author&query=Fruchter%2C+A+S">A. S. Fruchter</a>, <a href="/search/astro-ph?searchtype=author&query=Gompertz%2C+B+P">B. P. Gompertz</a>, <a href="/search/astro-ph?searchtype=author&query=Hjorth%2C+J">J. Hjorth</a>, <a href="/search/astro-ph?searchtype=author&query=Jakobsson%2C+P">P. Jakobsson</a>, <a href="/search/astro-ph?searchtype=author&query=Lyman%2C+J+D">J. D. Lyman</a>, <a href="/search/astro-ph?searchtype=author&query=O%27Brien%2C+P">P. O'Brien</a>, <a href="/search/astro-ph?searchtype=author&query=Perley%2C+D+A">D. A. Perley</a>, <a href="/search/astro-ph?searchtype=author&query=Tanvir%2C+N+R">N. R. Tanvir</a>, <a href="/search/astro-ph?searchtype=author&query=Wheatley%2C+P+J">P. J. Wheatley</a>, <a href="/search/astro-ph?searchtype=author&query=Wiersema%2C+K">K. Wiersema</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="1907.00213v1-abstract-short" style="display: inline;"> The number of long gamma-ray bursts (GRBs) known to have occurred in the distant Universe (z greater than 5) is small (approx 15), however these events provide a powerful way of probing star formation at the onset of galaxy evolution. In this paper, we present the case for GRB100205A being a largely overlooked high-redshift event. While initially noted as a high-z candidate, this event and its hos… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1907.00213v1-abstract-full').style.display = 'inline'; document.getElementById('1907.00213v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1907.00213v1-abstract-full" style="display: none;"> The number of long gamma-ray bursts (GRBs) known to have occurred in the distant Universe (z greater than 5) is small (approx 15), however these events provide a powerful way of probing star formation at the onset of galaxy evolution. In this paper, we present the case for GRB100205A being a largely overlooked high-redshift event. While initially noted as a high-z candidate, this event and its host galaxy have not been explored in detail. By combining optical and near-infrared Gemini afterglow imaging (at t less than 1.3 days since burst) with deep late-time limits on host emission from the Hubble Space Telescope, we show that the most likely scenario is that GRB100205A arose in the redshift range 4-8. GRB100205A is an example of a burst whose afterglow, even at 1 hour post-burst, could only be identified by 8m class IR observations, and suggests that such observations of all optically dark bursts may be necessary to significantly enhance the number of high-redshift GRBs known. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1907.00213v1-abstract-full').style.display = 'none'; document.getElementById('1907.00213v1-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 June, 2019; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> July 2019. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">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/1906.03493">arXiv:1906.03493</a> <span> [<a href="https://arxiv.org/pdf/1906.03493">pdf</a>, <a href="https://arxiv.org/format/1906.03493">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/ab8799">10.3847/1538-4357/ab8799 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> The late-time afterglow evolution of long gamma-ray bursts GRB 160625B and GRB 160509A </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Kangas%2C+T">Tuomas Kangas</a>, <a href="/search/astro-ph?searchtype=author&query=Fruchter%2C+A+S">Andrew S. Fruchter</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=Postigo%2C+A+d+U">Antonio de Ugarte Postigo</a>, <a href="/search/astro-ph?searchtype=author&query=Pe%27er%2C+A">Asaf Pe'er</a>, <a href="/search/astro-ph?searchtype=author&query=Vogel%2C+S+N">Stuart N. Vogel</a>, <a href="/search/astro-ph?searchtype=author&query=Cucchiara%2C+A">Antonino Cucchiara</a>, <a href="/search/astro-ph?searchtype=author&query=Gompertz%2C+B">Benjamin Gompertz</a>, <a href="/search/astro-ph?searchtype=author&query=Graham%2C+J">John Graham</a>, <a href="/search/astro-ph?searchtype=author&query=Levan%2C+A">Andrew Levan</a>, <a href="/search/astro-ph?searchtype=author&query=Misra%2C+K">Kuntal Misra</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=Racusin%2C+J">Judith Racusin</a>, <a href="/search/astro-ph?searchtype=author&query=Tanvir%2C+N">Nial Tanvir</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="1906.03493v3-abstract-short" style="display: inline;"> We present post-jet-break \textit{HST}, VLA and \textit{Chandra} observations of the afterglow of the long $纬$-ray bursts GRB 160625B (between 69 and 209 days) and GRB 160509A (between 35 and 80 days). We calculate the post-jet-break decline rates of the light curves, and find the afterglow of GRB 160625B inconsistent with a simple $t^{-3/4}$ steepening over the break, expected from the geometric… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1906.03493v3-abstract-full').style.display = 'inline'; document.getElementById('1906.03493v3-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1906.03493v3-abstract-full" style="display: none;"> We present post-jet-break \textit{HST}, VLA and \textit{Chandra} observations of the afterglow of the long $纬$-ray bursts GRB 160625B (between 69 and 209 days) and GRB 160509A (between 35 and 80 days). We calculate the post-jet-break decline rates of the light curves, and find the afterglow of GRB 160625B inconsistent with a simple $t^{-3/4}$ steepening over the break, expected from the geometric effect of the jet edge entering our line of sight. However, the favored optical post-break decline ($f_谓 \propto t^{-1.96 \pm 0.07}$) is also inconsistent with the $f_谓 \propto t^{-p}$ decline (where $p \approx 2.3$ from the pre-break light curve), which is expected from exponential lateral expansion of the jet; perhaps suggesting lateral expansion that only affects a fraction of the jet. The post-break decline of GRB 160509A is consistent with both the $t^{-3/4}$ steepening and with $f_谓 \propto t^{-p}$. We also use {\sc boxfit} to fit afterglow models to both light curves and find both to be energetically consistent with a millisecond magnetar central engine, although the magnetar parameters need to be extreme (i.e. $E \sim 3 \times 10^{52}$ erg). Finally, the late-time radio light curves of both afterglows are not reproduced well by {\sc boxfit} and are inconsistent with predictions from the standard jet model; instead both are well represented by a single power law decline (roughly $f_谓 \propto t^{-1}$) with no breaks. This requires a highly chromatic jet break ($t_{j,\mathrm{radio}} > 10 \times t_{j,\mathrm{optical}}$) and possibly a two-component jet for both bursts. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1906.03493v3-abstract-full').style.display = 'none'; document.getElementById('1906.03493v3-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 April, 2020; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 8 June, 2019; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> June 2019. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">19 pages, 9 figures. Revised version; 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/1905.02159">arXiv:1905.02159</a> <span> [<a href="https://arxiv.org/pdf/1905.02159">pdf</a>, <a href="https://arxiv.org/format/1905.02159">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/ab38bb">10.3847/1538-4357/ab38bb <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Short GRB 160821B: a reverse shock, a refreshed shock, and a well-sampled kilonova </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Lamb%2C+G+P">G. P. Lamb</a>, <a href="/search/astro-ph?searchtype=author&query=Tanvir%2C+N+R">N. R. Tanvir</a>, <a href="/search/astro-ph?searchtype=author&query=Levan%2C+A+J">A. J. Levan</a>, <a href="/search/astro-ph?searchtype=author&query=Postigo%2C+A+d+U">A. de Ugarte Postigo</a>, <a href="/search/astro-ph?searchtype=author&query=Kawaguchi%2C+K">K. Kawaguchi</a>, <a href="/search/astro-ph?searchtype=author&query=Corsi%2C+A">A. Corsi</a>, <a href="/search/astro-ph?searchtype=author&query=Evans%2C+P+A">P. A. Evans</a>, <a href="/search/astro-ph?searchtype=author&query=Gompertz%2C+B">B. Gompertz</a>, <a href="/search/astro-ph?searchtype=author&query=Malesani%2C+D+B">D. B. Malesani</a>, <a href="/search/astro-ph?searchtype=author&query=Page%2C+K+L">K. L. Page</a>, <a href="/search/astro-ph?searchtype=author&query=Wiersema%2C+K">K. Wiersema</a>, <a href="/search/astro-ph?searchtype=author&query=Rosswog%2C+S">S. Rosswog</a>, <a href="/search/astro-ph?searchtype=author&query=Shibata%2C+M">M. Shibata</a>, <a href="/search/astro-ph?searchtype=author&query=Tanaka%2C+M">M. Tanaka</a>, <a href="/search/astro-ph?searchtype=author&query=van+der+Horst%2C+A+J">A. J. van der Horst</a>, <a href="/search/astro-ph?searchtype=author&query=Cano%2C+Z">Z. Cano</a>, <a href="/search/astro-ph?searchtype=author&query=Fynbo%2C+J+P+U">J. P. U. Fynbo</a>, <a href="/search/astro-ph?searchtype=author&query=Fruchter%2C+A+S">A. S. Fruchter</a>, <a href="/search/astro-ph?searchtype=author&query=Greiner%2C+J">J. Greiner</a>, <a href="/search/astro-ph?searchtype=author&query=Heintz%2C+K">K. Heintz</a>, <a href="/search/astro-ph?searchtype=author&query=Higgins%2C+A">A. Higgins</a>, <a href="/search/astro-ph?searchtype=author&query=Hjorth%2C+J">J. Hjorth</a>, <a href="/search/astro-ph?searchtype=author&query=Izzo%2C+L">L. Izzo</a>, <a href="/search/astro-ph?searchtype=author&query=Jakobsson%2C+P">P. Jakobsson</a>, <a href="/search/astro-ph?searchtype=author&query=Kann%2C+D+A">D. A. Kann</a> , et al. (9 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="1905.02159v3-abstract-short" style="display: inline;"> We report our identification of the optical afterglow and host galaxy of the short-duration gamma-ray burst GRB 160821B. The spectroscopic redshift of the host is $z=0.162$, making it one of the lowest redshift sGRBs identified by Swift. Our intensive follow-up campaign using a range of ground-based facilities as well as HST, XMM and Swift, shows evidence for a late-time excess of optical and near… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1905.02159v3-abstract-full').style.display = 'inline'; document.getElementById('1905.02159v3-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1905.02159v3-abstract-full" style="display: none;"> We report our identification of the optical afterglow and host galaxy of the short-duration gamma-ray burst GRB 160821B. The spectroscopic redshift of the host is $z=0.162$, making it one of the lowest redshift sGRBs identified by Swift. Our intensive follow-up campaign using a range of ground-based facilities as well as HST, XMM and Swift, shows evidence for a late-time excess of optical and near-infrared emission in addition to a complex afterglow. The afterglow light-curve at X-ray frequencies reveals a narrow jet, $胃_j\sim1.9^{+0.10}_{-0.03}$ deg, that is refreshed at $>1$ day post-burst by a slower outflow with significantly more energy than the initial outflow that produced the main GRB. Observations of the 5 GHz radio afterglow shows a reverse shock into a mildly magnetised shell. The optical and near-infrared excess is fainter than AT2017gfo associated with GW170817, and is well explained by a kilonova with dynamic ejecta mass $M_{\rm dyn}=(1.0\pm0.6)\times10^{-3}$ M$_{\odot}$ and a secular (postmerger) ejecta mass with $M_{\rm pm}=(1.0\pm0.6)\times10^{-2}$ M$_\odot$, consistent with a binary neutron star merger resulting in a short-lived massive neutron star. This optical and near-infrared dataset provides the best-sampled kilonova light-curve without a gravitational wave trigger to date. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1905.02159v3-abstract-full').style.display = 'none'; document.getElementById('1905.02159v3-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 August, 2019; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 6 May, 2019; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> May 2019. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">17 pages, 6 figures, Version accepted by ApJ</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1811.11491">arXiv:1811.11491</a> <span> [<a href="https://arxiv.org/pdf/1811.11491">pdf</a>, <a href="https://arxiv.org/format/1811.11491">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/10.3847/2041-8213/aaf96b">10.3847/2041-8213/aaf96b <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> The optical afterglow of GW170817 at one year post-merger </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Lamb%2C+G+P">G. P. Lamb</a>, <a href="/search/astro-ph?searchtype=author&query=Lyman%2C+J+D">J. D. Lyman</a>, <a href="/search/astro-ph?searchtype=author&query=Levan%2C+A+J">A. J. Levan</a>, <a href="/search/astro-ph?searchtype=author&query=Tanvir%2C+N+R">N. R. Tanvir</a>, <a href="/search/astro-ph?searchtype=author&query=Kangas%2C+T">T. Kangas</a>, <a href="/search/astro-ph?searchtype=author&query=Fruchter%2C+A+S">A. S. Fruchter</a>, <a href="/search/astro-ph?searchtype=author&query=Gompertz%2C+B">B. Gompertz</a>, <a href="/search/astro-ph?searchtype=author&query=Hjorth%2C+J">J. Hjorth</a>, <a href="/search/astro-ph?searchtype=author&query=Mandel%2C+I">I. Mandel</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=Steeghs%2C+D">D. Steeghs</a>, <a href="/search/astro-ph?searchtype=author&query=Wiersema%2C+K">K. Wiersema</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="1811.11491v2-abstract-short" style="display: inline;"> We present observations of the optical afterglow of GRB\,170817A, made by the {\it Hubble Space Telescope}, between February and August 2018, up to one year after the neutron star merger, GW170817. The afterglow shows a rapid decline beyond $170$~days, and confirms the jet origin for the observed outflow, in contrast to more slowly declining expectations for `failed-jet' scenarios. We show here th… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1811.11491v2-abstract-full').style.display = 'inline'; document.getElementById('1811.11491v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1811.11491v2-abstract-full" style="display: none;"> We present observations of the optical afterglow of GRB\,170817A, made by the {\it Hubble Space Telescope}, between February and August 2018, up to one year after the neutron star merger, GW170817. The afterglow shows a rapid decline beyond $170$~days, and confirms the jet origin for the observed outflow, in contrast to more slowly declining expectations for `failed-jet' scenarios. We show here that the broadband (radio, optical, X-ray) afterglow is consistent with a structured outflow where an ultra-relativistic jet, with Lorentz factor $螕\gtrsim100$, forms a narrow core ($\sim5^\circ$) and is surrounded by a wider angular component that extends to $\sim15^\circ$, which is itself relativistic ($螕\gtrsim5$). For a two-component model of this structure, the late-time optical decline, where $F \propto t^{-伪}$, is $伪=2.20\pm0.18$, and for a Gaussian structure the decline is $伪=2.45\pm0.23$. We find the Gaussian model to be consistent with both the early $\sim10$ days and late $\gtrsim290$ days data. The agreement of the optical light curve with the evolution of the broadband spectral energy distribution and its continued decline indicates that the optical flux is arising primarily from the afterglow and not any underlying host system. This provides the deepest limits on any host stellar cluster, with a luminosity $\lesssim 4000 L_\odot~(M_{\rm F606W}\gtrsim-4.3)$. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1811.11491v2-abstract-full').style.display = 'none'; document.getElementById('1811.11491v2-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 December, 2018; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 28 November, 2018; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> November 2018. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">8 pages, 3 figures, accepted for publication in ApJL</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1809.04190">arXiv:1809.04190</a> <span> [<a href="https://arxiv.org/pdf/1809.04190">pdf</a>, <a href="https://arxiv.org/format/1809.04190">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"> A Comparison between Radio Loud and Quiet Gamma-Ray Bursts, and Evidence for a Potential Correlation between Intrinsic Duration and Redshift in the Radio Loud Population </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Lloyd-Ronning%2C+N+M">Nicole M. Lloyd-Ronning</a>, <a href="/search/astro-ph?searchtype=author&query=Gompertz%2C+B">Ben Gompertz</a>, <a href="/search/astro-ph?searchtype=author&query=Pe%27er%2C+A">Asaf Pe'er</a>, <a href="/search/astro-ph?searchtype=author&query=Dainotti%2C+M">Maria Dainotti</a>, <a href="/search/astro-ph?searchtype=author&query=Fruchter%2C+A">Andy Fruchter</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="1809.04190v2-abstract-short" style="display: inline;"> We extend our study of energetic radio loud and quiet gamma-ray bursts (GRBs), suggesting these GRBs potentially come from two separate progenitor systems. We expand the sample from our previous paper (Lloyd-Ronning & Fryer, 2017) and find our results are strengthened - radio quiet GRBs have significantly shorter intrinsic prompt duration, and are also less energetic on average. However, the tenuo… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1809.04190v2-abstract-full').style.display = 'inline'; document.getElementById('1809.04190v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1809.04190v2-abstract-full" style="display: none;"> We extend our study of energetic radio loud and quiet gamma-ray bursts (GRBs), suggesting these GRBs potentially come from two separate progenitor systems. We expand the sample from our previous paper (Lloyd-Ronning & Fryer, 2017) and find our results are strengthened - radio quiet GRBs have significantly shorter intrinsic prompt duration, and are also less energetic on average. However, the tenuous correlation between isotropic energy and intrinsic duration in the radio dark sample remains tenuous and is slightly weakened by adding more bursts. Interestingly, we find an anti-correlation between the intrinsic duration and redshift in the radio bright sample but not the radio dark sample, further supporting that these two samples may come from separate progenitors. We also find that very high energy (0.1 - 100 GeV) extended emission is only present in the radio loud sample. There is no significant difference between the presence of X-ray/optical plateaus or the average jet opening angles between the two samples. We explore the interpretation of these results in the context of different progenitor models. The data are consistent with the radio loud GRBs coming from a Helium-merger system and the radio quiet GRBs coming from a collapsar system, but may also reflect other dichotomies in the inner engine such as a neutron star versus black hole core. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1809.04190v2-abstract-full').style.display = 'none'; document.getElementById('1809.04190v2-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 December, 2018; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 11 September, 2018; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> September 2018. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">Accepted to ApJ</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Report number:</span> LA-UR-18-28535 </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1808.09228">arXiv:1808.09228</a> <span> [<a href="https://arxiv.org/pdf/1808.09228">pdf</a>, <a href="https://arxiv.org/ps/1808.09228">ps</a>, <a href="https://arxiv.org/format/1808.09228">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Astrophysics of Galaxies">astro-ph.GA</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="High Energy Astrophysical Phenomena">astro-ph.HE</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1093/mnras/sty2371">10.1093/mnras/sty2371 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Infrared molecular hydrogen lines in GRB host galaxies </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Wiersema%2C+K">K. Wiersema</a>, <a href="/search/astro-ph?searchtype=author&query=Togi%2C+A">A. Togi</a>, <a href="/search/astro-ph?searchtype=author&query=Watson%2C+D">D. Watson</a>, <a href="/search/astro-ph?searchtype=author&query=Christensen%2C+L">L. Christensen</a>, <a href="/search/astro-ph?searchtype=author&query=Fynbo%2C+J+P+U">J. P. U. Fynbo</a>, <a href="/search/astro-ph?searchtype=author&query=Gompertz%2C+B+P">B. P. Gompertz</a>, <a href="/search/astro-ph?searchtype=author&query=Higgins%2C+A+B">A. B. Higgins</a>, <a href="/search/astro-ph?searchtype=author&query=Levan%2C+A+J">A. J. Levan</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=Schulze%2C+S">S. Schulze</a>, <a href="/search/astro-ph?searchtype=author&query=Smith%2C+J+D+T">J. D. T. Smith</a>, <a href="/search/astro-ph?searchtype=author&query=Stanway%2C+E+R">E. R. Stanway</a>, <a href="/search/astro-ph?searchtype=author&query=Starling%2C+R+L+C">R. L. C. Starling</a>, <a href="/search/astro-ph?searchtype=author&query=Steeghs%2C+D">D. Steeghs</a>, <a href="/search/astro-ph?searchtype=author&query=Tanvir%2C+N+R">N. R. Tanvir</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="1808.09228v1-abstract-short" style="display: inline;"> Molecular species, most frequently H_2, are present in a small, but growing, number of gamma-ray burst (GRB) afterglow spectra at redshifts z~2-3, detected through their rest-frame UV absorption lines. In rare cases, lines of vibrationally excited states of H_2 can be detected in the same spectra. The connection between afterglow line-of-sight absorption properties of molecular (and atomic) gas, a… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1808.09228v1-abstract-full').style.display = 'inline'; document.getElementById('1808.09228v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1808.09228v1-abstract-full" style="display: none;"> Molecular species, most frequently H_2, are present in a small, but growing, number of gamma-ray burst (GRB) afterglow spectra at redshifts z~2-3, detected through their rest-frame UV absorption lines. In rare cases, lines of vibrationally excited states of H_2 can be detected in the same spectra. The connection between afterglow line-of-sight absorption properties of molecular (and atomic) gas, and the observed behaviour in emission of similar sources at low redshift, is an important test of the suitability of GRB afterglows as general probes of conditions in star formation regions at high redshift. Recently, emission lines of carbon monoxide have been detected in a small sample of GRB host galaxies, at sub-mm wavelengths, but no searches for H_2 in emission have been reported yet. In this paper we perform an exploratory search for rest-frame K band rotation-vibrational transitions of H_2 in emission, observable only in the lowest redshift GRB hosts (z<0.22). Searching the data of four host galaxies, we detect a single significant rotation-vibrational H_2 line candidate, in the host of GRB 031203. Re-analysis of Spitzer mid-infrared spectra of the same GRB host gives a single low significance rotational line candidate. The (limits on) line flux ratios are consistent with those of blue compact dwarf galaxies in the literature. New instrumentation, in particular on the JWST and the ELT, can facilitate a major increase in our understanding of the H_2 properties of nearby GRB hosts, and the relation to H_2 absorption in GRBs at higher redshift. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1808.09228v1-abstract-full').style.display = 'none'; document.getElementById('1808.09228v1-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 August, 2018; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> August 2018. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">7 pages, 4 figures, MNRAS accepted</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1805.09022">arXiv:1805.09022</a> <span> [<a href="https://arxiv.org/pdf/1805.09022">pdf</a>, <a href="https://arxiv.org/format/1805.09022">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/sty1363">10.1093/mnras/sty1363 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Fallback accretion on to a newborn magnetar: long GRBs with giant X-ray flares </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Gibson%2C+S+L">Sarah L. Gibson</a>, <a href="/search/astro-ph?searchtype=author&query=Wynn%2C+G+A">Graham A. Wynn</a>, <a href="/search/astro-ph?searchtype=author&query=Gompertz%2C+B+P">Benjamin P. Gompertz</a>, <a href="/search/astro-ph?searchtype=author&query=O%27Brien%2C+P+T">Paul T. O'Brien</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="1805.09022v1-abstract-short" style="display: inline;"> Flares in the X-ray afterglow of gamma-ray bursts (GRBs) share more characteristics with the prompt emission than the afterglow, such as pulse profile and contained fluence. As a result, they are believed to originate from late-time activity of the central engine and can be used to constrain the overall energy budget. In this paper, we collect a sample of $19$ long GRBs observed by \emph{Swift}-XR… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1805.09022v1-abstract-full').style.display = 'inline'; document.getElementById('1805.09022v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1805.09022v1-abstract-full" style="display: none;"> Flares in the X-ray afterglow of gamma-ray bursts (GRBs) share more characteristics with the prompt emission than the afterglow, such as pulse profile and contained fluence. As a result, they are believed to originate from late-time activity of the central engine and can be used to constrain the overall energy budget. In this paper, we collect a sample of $19$ long GRBs observed by \emph{Swift}-XRT that contain giant flares in their X-ray afterglows. We fit this sample with a version of the magnetar propeller model, modified to include fallback accretion. This model has already successfully reproduced extended emission in short GRBs. Our best fits provide a reasonable morphological match to the light curves. However, $16$ out of $19$ of the fits require efficiencies for the propeller mechanism that approach $100\%$. The high efficiency parameters are a direct result of the high energy contained in the flares and the extreme duration of the dipole component, which forces either slow spin periods or low magnetic fields. We find that even with the inclusion of significant fallback accretion, in all but a few cases it is energetically challenging to produce prompt emission, afterglow and giant flares within the constraints of the rotational energy budget of a magnetar. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1805.09022v1-abstract-full').style.display = 'none'; document.getElementById('1805.09022v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 23 May, 2018; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> May 2018. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">8 pages, 2 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/1802.07730">arXiv:1802.07730</a> <span> [<a href="https://arxiv.org/pdf/1802.07730">pdf</a>, <a href="https://arxiv.org/format/1802.07730">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/aadba8">10.3847/1538-4357/aadba8 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> The Environments of the Most Energetic Gamma-Ray Bursts </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Gompertz%2C+B+P">B. P. Gompertz</a>, <a href="/search/astro-ph?searchtype=author&query=Fruchter%2C+A+S">A. S. Fruchter</a>, <a href="/search/astro-ph?searchtype=author&query=Pe%27er%2C+A">A. Pe'er</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="1802.07730v2-abstract-short" style="display: inline;"> We analyze the properties of a sample of long gamma-ray bursts (LGRBs) detected by the Fermi satellite that have a spectroscopic redshift and good follow-up coverage at both X-ray and optical/nIR wavelengths. The evolution of LGRB afterglows depends on the density profile of the external medium, enabling us to separate wind or ISM-like environments based on the observations. We do this by identify… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1802.07730v2-abstract-full').style.display = 'inline'; document.getElementById('1802.07730v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1802.07730v2-abstract-full" style="display: none;"> We analyze the properties of a sample of long gamma-ray bursts (LGRBs) detected by the Fermi satellite that have a spectroscopic redshift and good follow-up coverage at both X-ray and optical/nIR wavelengths. The evolution of LGRB afterglows depends on the density profile of the external medium, enabling us to separate wind or ISM-like environments based on the observations. We do this by identifying the environment that provides the best agreement between estimates of $p$, the index of the underlying power-law distribution of electron energies, as determined by the behavior of the afterglow in different spectral/temporal regimes. At 11 rest-frame hours after trigger, we find a roughly even split between ISM-like and wind-like environments. We further find a 2$蟽$ separation in the prompt emission energy distributions of wind-like and ISM-like bursts. We investigate the underlying physical parameters of the shock, and calculate the (degenerate) product of density and magnetic field energy ($蔚_B$). We show that $蔚_B$ must be $\ll 10^{-2}$ to avoid implied densities comparable to the intergalactic medium. Finally, we find that the most precisely constrained observations disagree on $p$ by more than would be expected based on observational errors alone. This suggests additional sources of error that are not incorporated in the standard afterglow theory. For the first time, we provide a measurement of this intrinsic error which can be represented as an error in the estimate of $p$ of magnitude $0.25 \pm 0.04$. When this error is included in the fits, the number of LGRBs with an identified environment drops substantially, but the equal division between the two types remains. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1802.07730v2-abstract-full').style.display = 'none'; document.getElementById('1802.07730v2-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 August, 2018; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 21 February, 2018; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> February 2018. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">31 pages (+14 appendix), 9 figures, 6 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/1801.02669">arXiv:1801.02669</a> <span> [<a href="https://arxiv.org/pdf/1801.02669">pdf</a>, <a href="https://arxiv.org/format/1801.02669">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="High Energy Astrophysical Phenomena">astro-ph.HE</span> </div> </div> <p class="title is-5 mathjax"> The optical afterglow of the short gamma-ray burst associated with GW170817 </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Lyman%2C+J+D">J. D. Lyman</a>, <a href="/search/astro-ph?searchtype=author&query=Lamb%2C+G+P">G. P. Lamb</a>, <a href="/search/astro-ph?searchtype=author&query=Levan%2C+A+J">A. J. Levan</a>, <a href="/search/astro-ph?searchtype=author&query=Mandel%2C+I">I. Mandel</a>, <a href="/search/astro-ph?searchtype=author&query=Tanvir%2C+N+R">N. R. Tanvir</a>, <a href="/search/astro-ph?searchtype=author&query=Kobayashi%2C+S">S. Kobayashi</a>, <a href="/search/astro-ph?searchtype=author&query=Gompertz%2C+B">B. Gompertz</a>, <a href="/search/astro-ph?searchtype=author&query=Hjorth%2C+J">J. Hjorth</a>, <a href="/search/astro-ph?searchtype=author&query=Fruchter%2C+A+S">A. S. Fruchter</a>, <a href="/search/astro-ph?searchtype=author&query=Kangas%2C+T">T. Kangas</a>, <a href="/search/astro-ph?searchtype=author&query=Steeghs%2C+D">D. Steeghs</a>, <a href="/search/astro-ph?searchtype=author&query=Steele%2C+I+A">I. A. Steele</a>, <a href="/search/astro-ph?searchtype=author&query=Cano%2C+Z">Z. Cano</a>, <a href="/search/astro-ph?searchtype=author&query=Copperwheat%2C+C">C. Copperwheat</a>, <a href="/search/astro-ph?searchtype=author&query=Evans%2C+P+A">P. A. Evans</a>, <a href="/search/astro-ph?searchtype=author&query=Fynbo%2C+J+P+U">J. P. U. Fynbo</a>, <a href="/search/astro-ph?searchtype=author&query=Gall%2C+C">C. Gall</a>, <a href="/search/astro-ph?searchtype=author&query=Im%2C+M">M. Im</a>, <a href="/search/astro-ph?searchtype=author&query=Izzo%2C+L">L. Izzo</a>, <a href="/search/astro-ph?searchtype=author&query=Jakobsson%2C+P">P. Jakobsson</a>, <a href="/search/astro-ph?searchtype=author&query=Milvang-Jensen%2C+B">B. Milvang-Jensen</a>, <a href="/search/astro-ph?searchtype=author&query=O%27Brien%2C+P">P. O'Brien</a>, <a href="/search/astro-ph?searchtype=author&query=Osborne%2C+J+P">J. P. Osborne</a>, <a href="/search/astro-ph?searchtype=author&query=Palazzi%2C+E">E. Palazzi</a>, <a href="/search/astro-ph?searchtype=author&query=Perley%2C+D+A">D. A. Perley</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="1801.02669v3-abstract-short" style="display: inline;"> The binary neutron star merger GW170817 was the first multi-messenger event observed in both gravitational and electromagnetic waves. The electromagnetic signal began approximately 2 seconds post-merger with a weak, short burst of gamma-rays, which was followed over the next hours and days by the ultraviolet, optical and near-infrared emission from a radioactively- powered kilonova. Later, non-the… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1801.02669v3-abstract-full').style.display = 'inline'; document.getElementById('1801.02669v3-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1801.02669v3-abstract-full" style="display: none;"> The binary neutron star merger GW170817 was the first multi-messenger event observed in both gravitational and electromagnetic waves. The electromagnetic signal began approximately 2 seconds post-merger with a weak, short burst of gamma-rays, which was followed over the next hours and days by the ultraviolet, optical and near-infrared emission from a radioactively- powered kilonova. Later, non-thermal rising X-ray and radio emission was observed. The low luminosity of the gamma-rays and the rising non-thermal flux from the source at late times could indicate that we are outside the opening angle of the beamed relativistic jet. Alternatively, the emission could be arising from a cocoon of material formed from the interaction between a jet and the merger ejecta. Here we present late-time optical detections and deep near-infrared limits on the emission from GW170817 at 110 days post-merger. Our new observations are at odds with expectations of late-time emission from kilonova models, being too bright and blue. Instead, the emission arises from the interaction between the relativistic ejecta of GW170817 and the interstellar medium. We show that this emission matches the expectations of a Gaussian structured relativistic jet, which would have launched a high luminosity short GRB to an aligned observer. However, other jet structure or cocoon models can also match current data - the future evolution of the afterglow will directly distinguish the origin of the emission. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1801.02669v3-abstract-full').style.display = 'none'; document.getElementById('1801.02669v3-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 19 September, 2018; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 8 January, 2018; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> January 2018. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">Includes MCMC fitting</span> </p> </li> </ol> <nav class="pagination is-small is-centered breathe-horizontal" 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