Insight-HXMT Observations of the Extremely Bright GRB 221009A

作者：Wen-Long Zhang, W. C. Xue, Cheng-Kui Li, S. L. Xiong, Gang Li, Yong Chen, Weiwei Cui, Xiao‐Bo Li, Congzhan Liu, M. Y. Ge, Wen-Jun Tan, Jia-Cong Liu, Chen-Wei Wang, Chao Zheng, Yan-Qiu Zhang, Y. Wang, Zhen Zhang, Shu-Xu Yi, Shuo Xiao, Ce Cai, Shuang-Xi Yi, L. M. Song, Lian Tao, Shuang‐Nan Zhang, Shuang‐Nan Zhang · 发表于：The Astrophysical Journal · 年份：2025 · DOI：10.3847/1538-4357/add14f · 被引用次数：6 · 研究领域：Gamma-ray bursts and supernovae、Astrophysics and Cosmic Phenomena、Pulsars and Gravitational Waves Research

Abstract The Insight Hard X-ray Modulation Telescope (Insight-HXMT) detected GRB 221009A, the brightest gamma-ray burst (GRB) observed to date, with all its three telescopes, i.e., the High Energy (HE) telescope (20–250 keV), Medium Energy (ME) telescope (5–30 keV), and Low Energy (LE) telescope (1–10 keV). Here we present the detailed observation results of all three telescopes of Insight-HXMT on the prompt emission of GRB 221009A. After dead-time and data saturation correction, we recovered the light curves of the HE, ME, and LE telescopes and find that they generally track the low-gain light curves of the third member of the Gravitational Wave High-energy Electromagnetic Counterpart All-sky Monitor (GECAM-C) that are free of data saturation issues. Particularly, the ME light curve matches the GECAM-C light curve in low gain mode above 400 keV, while the LE light curve is more consistent with the GECAM-C above 1.5 MeV. Based on simulation, we find that the signals recorded by ME and LE are actually caused by the secondary particles produced by the interaction between GRB gamma-ray photons and the material of the satellite. Interestingly, the consistency between the ME and LE light curves and GECAM-C demonstrates that ME and LE data could be used to characterize the GRB properties. Especially, the high-time-resolution light curve of ME allowed us, for the first time, to calculate the minimum variability timescale (0.10 s) of the main burst episode of GRB 221009A.