Synchrotron Radiation Dominates the Extremely Bright GRB 221009A
| Autor: | Jun Yang, Xiao-Hong Zhao, Zhenyu Yan, Xiangyu Ivy Wang, Yan-Qiu Zhang, Zheng-Hua An, Ce Cai, Xin-Qiao Li, Zihan Li, Jia-Cong Liu, Zi-Ke Liu, Xiang Ma, Yan-Zhi Meng, Wen-Xi Peng, Rui Qiao, Lang Shao, Li-Ming Song, Wen-Jun Tan, Ping Wang, Chen-Wei Wang, Xiang-Yang Wen, Shuo Xiao, Wang-Chen Xue, Yu-Han Yang, Yi-Han Iris Yin, Bing Zhang, Fan Zhang, Shuai Zhang, Shuang-Nan Zhang, Chao Zheng, Shi-Jie Zheng, Shao-Lin Xiong, Bin-Bin Zhang |
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| Jazyk: | angličtina |
| Rok vydání: | 2023 |
| Předmět: | |
| Zdroj: | The Astrophysical Journal Letters, Vol 947, Iss 1, p L11 (2023) |
| Druh dokumentu: | article |
| ISSN: | 2041-8213 2041-8205 |
| DOI: | 10.3847/2041-8213/acc84b |
| Popis: | The brightest gamma-ray burst, GRB 221009A, has spurred numerous theoretical investigations, with particular attention paid to the origins of ultrahigh-energy TeV photons during the prompt phase. However, analyzing the mechanism of radiation of photons in the ∼MeV range has been difficult because the high flux causes pileup and saturation effects in most GRB detectors. In this Letter, we present systematic modeling of the time-resolved spectra of the GRB using unsaturated data obtained from the Fermi Gamma-ray Burst Monitor (precursor) and SATech-01/GECAM-C (main emission and flare). Our approach incorporates the synchrotron radiation model, which assumes an expanding emission region with relativistic speed and a global magnetic field that decays with radius, and successfully fits such a model to the observational data. Our results indicate that the spectra of the burst are fully in accordance with a synchrotron origin from relativistic electrons accelerated at a large emission radius. The lack of thermal emission in the prompt emission spectra supports a Poynting flux–dominated jet composition. |
| Databáze: | Directory of Open Access Journals |
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