Long-duration Gamma-Ray Burst and Associated Kilonova Emission from Fast-spinning Black Hole–Neutron Star Mergers

作者：Jin-Ping Zhu, X. Wang, Hui Sun, Yuan-Pei Yang, Zhuo Li, Rui-Chong Hu, Ying Qin, Shichao Wu · 发表于：The Astrophysical Journal Letters · 年份：2022 · DOI：10.3847/2041-8213/ac85ad · 被引用次数：48 · 研究领域：Gamma-ray bursts and supernovae、Pulsars and Gravitational Waves Research、Astrophysical Phenomena and Observations

Abstract Gamma-ray bursts (GRBs) have been phenomenologically divided into long- and short-duration populations, generally corresponding to collapsar and compact merger origins, respectively. Here, we collect three unique bursts, GRBs 060614, 211211A, and 211227A, all of which are characterized by a long-duration main emission (ME) phase and a rebrightening extended emission (EE) phase, to study their observed properties and their potential origins as neutron star–black hole (NSBH) mergers. NS-first-born (BH-first-born) NSBH mergers tend to contain fast-spinning (nonspinning) BHs that more easily (hardly) allow tidal disruption to occur, while (without) forming electromagnetic signals. We find that NS-first-born NSBH mergers can well interpret the origins of these three GRBs, supported by the following. (1) Their X-ray MEs and EEs show unambiguous fallback accretion signatures, decreasing as ∝ t −5/3 , which might account for their long durations. The EEs could result from the fallback accretion of r -process heating materials, which is predicted to occur after NSBH mergers. (2) The beaming-corrected local event-rate density for these types of merger-origin long-duration GRBs is  0 ∼ 2.4 − 1.3 + 2.3 Gpc − 3 yr − 1 , consistent with that of NS-first-born NSBH mergers. (3) Our detailed analysis of the EE, afterglow, and kilonova of the recent high-impact event GRB 211211A reveals that it co...