GRB 220408B: A Three-Episode Burst from a Precessing Jet
Abstract
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 {\it Letter}, 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 seconds, a nutation period of seconds and viewed off-axis. This study provides a straightforward explanation for the complex yet similar multi-episode GRB light curves.
Keywords
Cite
@article{arxiv.2302.03215,
title = {GRB 220408B: A Three-Episode Burst from a Precessing Jet},
author = {Zijian Zhang and Yihan Yin and Chenyu Wang and Xiangyu Ivy Wang and Jun Yang and Yan-Zhi Meng and Zi-Ke Liu and Guo-Yin Chen and Xiaoping Fu and Huaizhong Gao and Sihao Li and Yihui Liu and Xiangyun Long and Yong-Chang Ma and Xiaofan Pan and Yuanze Sun and Wei Wu and Zirui Yang and Zhizhen Ye and Xiaoyu Yu and Shuheng Zhao and Xutao Zheng and Tao Zhou and Qing-Wen Tang and Qiurong Yan and Rong Zhou and Zhonghai Wang and Hua Feng and Ming Zeng and Bin-Bin Zhang},
journal= {arXiv preprint arXiv:2302.03215},
year = {2023}
}
Comments
11 pages, 3 tables, 8 figures