Discovery and confirmation of the shortest gamma-ray burst from a collapsar
Discovery and confirmation of the shortest gamma-ray burst from a collapsar
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DOI：
10.1038/s41550-021-01428-7
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发表时间：
2021-07-26
期刊：
影响因子：
14.1
通讯作者：
Valeev, Azamat F.
中科院分区：
文献类型：
--
作者：
Ahumada, Tomas;Singer, Leo P.;Valeev, Azamat F.
伽马射线暴（GRB）是宇宙中最亮、最具能量的事件之一。伽玛暴的持续时间和硬度分布有两个簇(1)，现在被认为反映了（至少）两个不同的祖细胞(2)。短硬伽玛暴（SGRB；T-90 < 2 s）源自致密双星合并，而长软伽玛暴（LGRB；T-90 > 2 s）则归因于特殊大质量恒星（塌缩星）的塌缩(3)。 SN 1998bw/GRB 980425（参考文献（4））的发现标志着短暴与塌缩星的首次关联，而 AT 2017gfo（参考文献（5））/GRB 170817A/GW170817（参考文献（6））的发现标志着短暴与双中子星合并的首次关联，双中子星合并也产生了引力波。在这里，我们介绍了 ZTF20abwysqy (AT2020scz) 的发现，这是费米卫星和 GRB 200826A 行星际网络定位区域中的快衰落光瞬变； X射线和无线电发射进一步证实这是余辉。后续成像（静止帧 16.5 天）显示余辉上方的过量发射，无法解释为潜在的千新星，但这与超新星一致。尽管GRB持续时间很短（静止帧T-90为0.65秒），但我们的全色后续数据证实了塌缩星起源。 GRB 200826A 是发现的与塌缩星相关的最短的 LGRB；它似乎处于成功塌陷和失败塌陷之间的边缘。我们的发现与大多数塌缩星无法产生超相对论喷流的假设是一致的。
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(1), now understood to reflect (at least) two different progenitors(2). Short-hard GRBs (SGRBs; T-90 < 2 s) arise from compact binary mergers, and long-soft GRBs (LGRBs; T-90 > 2 s) have been attributed to the collapse of peculiar massive stars (collapsars)(3). The discovery of SN 1998bw/GRB 980425 (ref. (4)) marked the first association of an LGRB with a collapsar, and AT 2017gfo (ref. (5))/GRB 170817A/GW170817 (ref. (6)) marked the first association of an SGRB with a binary neutron star merger, which also produced a gravitational wave. Here, we present the discovery of ZTF20abwysqy (AT2020scz), a fast-fading optical transient in the Fermi satellite and the Interplanetary Network 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, but which is consistent with being the supernova. Although the GRB duration is short (rest-frame T-90 of 0.65 s), our panchromatic follow-up data confirm 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.