Department of Astronomy, University of Maryland, College Park, MD, USA.
Astroparticle Physics Laboratory, NASA/GSFC, Greenbelt, MD, USA.
Nature. 2023 Jan;613(7943):253-256. doi: 10.1038/s41586-022-05497-0. Epub 2023 Jan 9.
Short gamma-ray bursts (GRBs) are associated with binary neutron star mergers, which are multimessenger astronomical events that have been observed both in gravitational waves and in the multiband electromagnetic spectrum. Depending on the masses of the stars in the binary and on details of their largely unknown equation of state, a dynamically evolving and short-lived neutron star may be formed after the merger, existing for approximately 10-300 ms before collapsing to a black hole. Numerical relativity simulations across different groups consistently show broad power spectral features in the 1-5-kHz range in the post-merger gravitational-wave signal, which is inaccessible by current gravitational-wave detectors but could be seen by future third-generation ground-based detectors in the next decade. This implies the possibility of quasiperiodic modulation of the emitted gamma rays in a subset of events in which a neutron star is formed shortly before the final collapse to a black hole. Here we present two such signals identified in the short bursts GRB 910711 and GRB 931101B from archival Burst and Transient Source Experiment (BATSE) data, which are compatible with the predictions from numerical relativity.
短伽马射线暴（GRB）与双中子星合并有关，这是一种多信使天文事件，已经在引力波和多波段电磁光谱中观测到。根据双星中恒星的质量以及其大部分未知的物态方程的细节，合并后可能会形成一个动态演化且寿命短暂的中子星，存在时间约为 10-300ms，然后坍缩成黑洞。不同小组的数值相对论模拟一致显示，在合并后的引力波信号中存在 1-5kHz 范围内的宽功率谱特征，这是当前引力波探测器无法探测到的，但未来十年内新一代地面探测器可能会看到。这意味着在一小部分事件中，可能会出现发射伽马射线的准周期调制，其中在最终坍缩成黑洞之前不久形成了一颗中子星。在这里，我们从档案中的爆发和瞬变源实验（BATSE）数据中确定了两个这样的信号，这些信号与数值相对论的预测是一致的。
