GRB 220408B:A Three-episode Burst from a Precessing Jet  

作　　者：Zijian Zhang Yi-Han Iris Yin Chenyu Wang Xiangyu Ivy Wang Jun Yang Yan-Zhi Meng Zi-Ke Liu Guo-Yin Chen Xiaoping Fu Huaizhong Gao Sihao Li Yihui Liu Xiangyun Long Yong-Chang Ma Xiaofan Pan Yuanze Sun Wei Wu Zirui Yang Zhizhen Ye Xiaoyu Yu Shuheng Zhao Xutao Zheng Tao Zhou Qing-Wen Tang Qiurong Yan Rong Zhou Zhonghai Wang Hua Feng Ming Zeng Bin-Bin Zhang 

机构地区：[1]School of Astronomy and Space Science,Nanjing University,Nanjing 210093,China [2]School of Physics,Nanjing University,Nanjing 210093,China [3]Department of Astronomy,Tsinghua University,Beijing 100084,China [4]Key Laboratory of Modern Astronomy and Astrophysics,Nanjing University,Ministry of Education,Nanjing 210093,China [5]School of Information Engineering,Nanchang University,Nanchang 330031,China [6]Department of Engineering Physics,Tsinghua University,Beijing 100084,China [7]Department of Health Physics,China Institute for Radiation Protection,Taiyuan 300000,China [8]Key Laboratory of Radiation Physics and Technology of Ministry of Education,College of Physics of Sichuan University,Chengdu 610065,China [9]School of Artificial Intelligence,Nanjing University,Nanjing 210093,China [10]Key Laboratory of Particle and Radiation Imaging,Tsinghua University,Ministry of Education,Beijing 100084,China [11]Department of Computer Science and Technology,Nanjing University,Nanjing 210093,China [12]School of Chemistry and Chemical Engineering,Nanjing University,Nanjing 210093,China [13]College of Engineering and Applied Sciences,Nanjing University,Nanjing 210093,China [14]Department of Physics,School of Physics and Materials Science,Nanchang University,Nanchang 330031,China [15]Purple Mountain Observatory,Chinese Academy of Sciences,Nanjing 210023,China

出　　处：《Research in Astronomy and Astrophysics》2023年第11期214-224,共11页天文和天体物理学研究（英文版）

基　　金：support by the National Key Research and Development Programs of China(2022YFF0711404,2022SKA0130102);the National SKA Program of China(2022SKA0130100);the National Natural Science Foundation of China(grant Nos.11833003,U2038105,U1831135,12121003);the science research grants from the China Manned Space Project with NO.CMS-CSST-2021-B11;the Fundamental Research Funds for the Central Universities;the Program for Innovative Talents and Entrepreneur in Jiangsu;supported by the National Postdoctoral Program for Innovative Talents(grant No.BX20200164)。

摘　　要：Jet precession has previously been proposed to explain the apparently repeating features in the light curves of a few gamma-ray bursts(GRBs).In this paper,we further apply the precession model to a bright GRB 220408B by examining both its temporal and spectral consistency with the predictions of the model.As one of the recently confirmed GRBs observed by our GRID CubeSat mission,GRB 220408B is noteworthy as it exhibits three apparently similar emission episodes.Furthermore,the similarities are reinforced by their strong temporal correlations and similar features in terms of spectral evolution and spectral lags.Our analysis demonstrates that these features can be well explained by the modulated emission of a Fast-Rise-Exponential-Decay(FRED)shape light curve intrinsically produced by a precessing jet with a precession period of 18.4_(-0.2)~(+0.2)s,a nutation period of11.1_(-0.2)~(+0.2)s and viewed off-axis.This study provides a straightforward explanation for the complex yet similar multiepisode GRB light curves.

关 键 词：gamma-rays:general (stars:)gamma-ray burst:individual(GRB 220408B) stars:jets 

分 类 号：P172.3[天文地球—天文学]