GECAM discovery of a peculiar magnetar X-ray burst (MXB 221120) from SGR J1935+2154 associated with a fast radio burst
Year: 2026
Type: article
Abstract: Fast radio bursts (FRBs) are enigmatic cosmic transients of millisecond duration observed in the radio band. The identification of FRB-associated magnetar X-ray bursts (MXBs) from the galactic magnetar SGR J1935+2154 suggests that at least a fraction of FRBs can be produced from magnetar activity. However, the sample size of FRB-associated MXBs is still very small. Here we report a bright and peculiar FRB-associated MXB from SGR J1935+2154 detected by GECAM on November 20, 2022, dubbed MXB 221120. We find that the temporal and spectral properties of MXB 221120 exhibit distinctive features. Its light curve could generally be described by a single FRED function with the superposition of several narrow pulses. Interestingly, we identified a possible quasiperiodic oscillation feature with a center frequency of ∼18 Hz in this MXB. The time-integrated spectrum is best fit by a blackbody model with a temperature ( kT ) of 18.6 keV, rendering it the first thermal spectrum FRB-associated MXB from SGR J1935+2154. Compared to other MXBs with a single emission episode, MXB 221120 has a longer duration and a higher blackbody temperature, making it an outlier in the burst sample. These results indicate that MXB 221120 may have been produced by a special mechanism with extreme physical conditions.
Source: Astronomy and Astrophysics
Authors: Wen-Jun Tan, Yue Wang, Chen-Wei Wang, Shao-Lin Xiong, Xiao-Bo Li, Shuang-Nan Zhang, Ce Cai, Wang-Chen Xue, Peng Zhang, Bo-Bing Wu, Zheng-Hua An, Ming Gao, Ming-Yu Ge, Ke Gong, Dong-Ya Guo, Hao-Xuan Guo, Long-Fei Hao, Yue Huang, Yu-Xiang Huang, Ke-Jia Lee, Bing Li, Kui-Cheng Li, Xin-Qiao Li, Jia-Cong Liu, Xiao-Jing Liu, Ya-Qing Liu, Xiang Ma, Wen-Xi Peng, Rui Qiao, Yang-Zhao Ren, Li-Ming Song, Xi-Lei Sun, Jin Wang, Jin-Zhou Wang, Ping Wang, Xiang-Yang Wen, Shuo Xiao, Lun-Sheng Xie, Heng Xu, Sheng Yang, Shu-Xu Yi, Qi-bin Yi, Zheng-Hang Yu, Li-Da Zhang, Fan Zhang, Hong-Mei Zhang, Jin-Peng Zhang, Yan-Qiu Zhang, Zhen Zhang, Xiao-Yun Zhao, Yi Zhao, Chao Zheng, Shi-Jie Zheng
Institutions: Chinese Academy of Sciences, Institute of High Energy Physics, University of Chinese Academy of Sciences, Hebei Normal University, Tongji University, Xi'an Jiaotong University, Yunnan Observatories, Peking University, National Astronomical Observatories, Southwest Jiaotong University, Guizhou Normal University, Central China Normal University, Yichun University, Dezhou University
Language: English
Subfield: Astronomy and Astrophysics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $1,865
OpenAlex ID: W7129021306