Zhang B-B, Zhang B, Sun H, Lei W-H, Gao H, Li Y, Shao L, Zhao Y, Hu Y-D, Lü H-J, Wu X-F, Fan X-L, Wang G, Castro-Tirado A J, Zhang S, Yu B-Y, Cao Y-Y, Liang E-W
School of Astronomy and Space Science, Nanjing University, 210093, Nanjing, China.
Instituto de Astrofísica de Andalucía (IAA-CSIC), P.O. Box 03004, E-18080, Granada, Spain.
Nat Commun. 2018 Jan 31;9(1):447. doi: 10.1038/s41467-018-02847-3.
Double neutron star (DNS) merger events are promising candidates of short gamma-ray burst (sGRB) progenitors as well as high-frequency gravitational wave (GW) emitters. On August 17, 2017, such a coinciding event was detected by both the LIGO-Virgo gravitational wave detector network as GW170817 and Gamma-Ray Monitor on board NASA's Fermi Space Telescope as GRB 170817A. Here, we show that the fluence and spectral peak energy of this sGRB fall into the lower portion of the distributions of known sGRBs. Its peak isotropic luminosity is abnormally low. The estimated event rate density above this luminosity is at least [Formula: see text] Gpc yr, which is close to but still below the DNS merger event rate density. This event likely originates from a structured jet viewed from a large viewing angle. There are similar faint soft GRBs in the Fermi archival data, a small fraction of which might belong to this new population of nearby, low-luminosity sGRBs.
双中子星（DNS）合并事件是短伽马射线暴（sGRB）前身星以及高频引力波（GW）发射源的有力候选者。2017年8月17日，LIGO - Virgo引力波探测器网络探测到一次此类并合事件，即GW170817；美国国家航空航天局费米太空望远镜搭载的伽马射线监测器也探测到该事件，即GRB 170817A。在此，我们表明此次sGRB的流量和光谱峰值能量落在已知sGRB分布的较低部分。其峰值各向同性光度异常低。高于此光度的估计事件率密度至少为[公式：见正文]Gpc⁻³ yr⁻¹，这接近但仍低于DNS合并事件率密度。该事件可能源于从大视角观测到的结构化喷流。费米存档数据中存在类似的微弱软伽马射线暴，其中一小部分可能属于这一附近低光度sGRB的新类别。
Zotero 插件
