Discovery and confirmation of the shortest gamma ray burst from a collapsar
Abstract
Gamma-ray bursts (GRBs) are among the brightest and most energetic events in the universe. The duration and hardness distribution of GRBs has two clusters, now understood to reflect (at least) two different progenitors. Short-hard GRBs (SGRBs; T90 <2 s) arise from compact binary mergers, while long-soft GRBs (LGRBs; T90 >2 s) have been attributed to the collapse of peculiar massive stars (collapsars). The discovery of SN 1998bw/GRB 980425 marked the first association of a LGRB with a collapsar and AT 2017gfo/GRB 170817A/GW170817 marked the first association of a SGRB with a binary neutron star merger, producing also gravitational wave (GW). Here, we present the discovery of ZTF20abwysqy (AT2020scz), a fast-fading optical transient in the Fermi Satellite and the InterPlanetary Network (IPN) localization regions of GRB 200826A; X-ray and radio emission further confirm that this is the afterglow. Follow-up imaging (at rest-frame 16.5 days) reveals excess emission above the afterglow that cannot be explained as an underlying kilonova (KN), but is consistent with being the supernova (SN). Despite the GRB duration being short (rest-frame T90 of 0.65 s), our panchromatic follow-up data confirms a collapsar origin. GRB 200826A is the shortest LGRB found with an associated collapsar; it appears to sit on the brink between a successful and a failed collapsar. Our discovery is consistent with the hypothesis that most collapsars fail to produce ultra-relativistic jets.
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Cite
@article{arxiv.2105.05067,
title = {Discovery and confirmation of the shortest gamma ray burst from a collapsar},
author = {Tomas Ahumada and Leo P. Singer and Shreya Anand and Michael W. Coughlin and Mansi M. Kasliwal and Geoffrey Ryan and Igor Andreoni and S. Bradley Cenko and Christoffer Fremling and Harsh Kumar and Peter T. H. Pang and Eric Burns and Virginia Cunningham and Simone Dichiara and Tim Dietrich and Dmitry S. Svinkin and Mouza Almualla and Alberto J. Castro-Tirado and Kishalay De and Rachel Dunwoody and Pradip Gatkine and Erica Hammerstein and Shabnam Iyyani and Joseph Mangan and Dan Perley and Sonalika Purkayastha and Eric Bellm and Varun Bhalerao and Bryce Bolin and Mattia Bulla and Christopher Cannella and Poonam Chandra and Dmitry A. Duev and Dmitry Frederiks and Avishay Gal-Yam and Matthew Graham and Anna Y. Q. Ho and Kevin Hurley and Viraj Karambelkar and Erik C. Kool and S. R. Kulkarni and Ashish Mahabal and Frank Masci and Sheila McBreen and Shashi B. Pandey and Simeon Reusch and Anna Ridnaia and Philippe Rosnet and Benjamin Rusholme and Ana Sagues Carracedo and Roger Smith and Maayane Soumagnac and Robert Stein and Eleonora Troja and Anastasia Tsvetkova and Richard Walters and Azamat F. Valeev},
journal= {arXiv preprint arXiv:2105.05067},
year = {2022}
}
Comments
submitted to Nature Astronomy