학술논문
The Peculiar Precursor of a Gamma-Ray Burst from a Binary Merger Involving a Magnetar
Document Type
Working Paper
Author
Xiao, Shuo; Zhang, Yan-Qiu; Zhu, Zi-Pei; Xiong, Shao-Lin; Gao, He; Xu, Dong; Zhang, Shuang-Nan; Peng, Wen-Xi; Li, Xiao-Bo; Zhang, Peng; Lu, Fang-Jun; Lin, Lin; Liu, Liang-Duan; Zhang, Zhen; Ge, Ming-Yu; Tuo, You-Li; Xue, Wang-Chen; Fu, Shao-Yu; Liu, Xing; Liu, Jin-Zhong; Li, An; Wang, Tian-Cong; Zheng, Chao; Wang, Yue; Jiang, Shuai-Qing; Li, Jin-Da; Liu, Jia-Cong; Cao, Zhou-Jian; Luo, Xi-Hong; Yang, Jiao-Jiao; Yi, Shu-Xu; Wang, Xi-Lu; Cai, Ce; Yi, Qi-Bin; Zhao, Yi; Xie, Sheng-Lun; Li, Cheng-Kui; Luo, Qi; Song, Li-Ming; Zhang, Shu; Qu, Jin-Lu; Liu, Cong-Zhan; Li, Xu-Fang; Xu, Yu-Peng; Li, Ti-Pei
Source
ApJ 970 6 (2024)
Subject
Language
Abstract
The milestone discovery of GW 170817-GRB 170817A-AT 2017gfo has shown that gravitational wave (GW) could be produced during the merger of neutron star-neutron star/black hole and that in electromagnetic (EM) wave a gamma-ray burst (GRB) and a kilonova (KN) are generated in sequence after the merger. Observationally, however, EM property before the merger phase is still unclear. Here we report a peculiar precursor in a KN-associated long-duration GRB 211211A, providing evidence of the EM before the merger. This precursor lasts $\sim$ 0.2 s, and the waiting time between the precursor and the main burst is $\sim$ 1 s, comparable to that between GW 170817 and GRB 170817A. The spectrum of the precursor could be well fit with a non-thermal cutoff power-law model instead of a blackbody. Especially, a $\sim$22 Hz Quasi-Periodic Oscillation candidate ($\sim 3\sigma$) is detected in the precursor. These temporal and spectral properties indicate that this precursor is probably produced by a catastrophic flare accompanying with magnetoelastic or crustal oscillations of a magnetar in binary compact merger. The strong magnetic field of the magnetar can also account for the prolonged duration of GRB 211211A. However, it poses a challenge to reconcile the rather short lifetime of a magnetar with the rather long spiraling time of a binary neutron star system only by the GW radiation before merger.
Comment: Published by ApJ. 13 pages, 11 figures
Comment: Published by ApJ. 13 pages, 11 figures