HXMT identification of a non-thermal X-ray burst from SGR J1935+2154 and with FRB 200428

• DOI: 10.1038/s41550-021-01302-6
• Publication Date: 2021-02-20T12:04:13Z
• Authors: C. K. Li; L. Lin; S. L. Xiong; M. Y. Ge; X. B. Li; T. P. Li; F. J. Lu; S. N. Zhang; Y. L. Tuo; Y. Nang; B. Zhang; S. Xiao; Y. Chen; L. M. Song; Y. P. Xu; C. Z. Liu; S. M. Jia; X. L. Cao; J. L. Qu; S. Zhang; Y. D. Gu; J. Y. Liao; X. F. Zhao; Y. Tan; J. Y. Nie; H. S. Zhao; S. J. Zheng; Y. G. Zheng; Q. Luo; C. Cai; B. Li; W. C. Xue; Q. C. Bu; Z. Chang; G. Chen; L. Chen; T. X. Chen; Y. B. Chen; Y. P. Chen; W. Cui; W. W. Cui; J. K. Deng; Y. W. Dong; Y. Y. Du; M. X. Fu; G. H. Gao; H. Gao; M. Gao; Y. D. Gu; J. Guan; C. C. Guo; D. W. Han; Y. Huang; J. Huo; L. H. Jiang; W. C. Jiang; J. Jin; Y. J. Jin; L. D. Kong; G. Li; M. S. Li; W. Li; X. Li; X. F. Li; Y. G. Li; Z. W. Li; X. H. Liang; B. S. Liu; G. Q. Liu; H. W. Liu; X. J. Liu; Y. N. Liu; B. Lu; X. F. Lu; T. Luo; X. Ma; B. Meng; G. Ou; N. Sai; R. C. Shang; X. Y. Song; L. Sun; L. Tao; C. Wang; G. F. Wang; J. Wang; W. S. Wang; Y. S. Wang; X. Y. Wen; B. B. Wu; B. Y. Wu; M. Wu; G. C. Xiao; H. Xu; J. W. Yang; S. Yang; Y. J. Yang; Yi-Jung Yang; Q. B. Yi; Q. Q. Yin; Y. You; A. M. Zhang; C. M. Zhang; F. Zhang; H. M. Zhang; J. Zhang; T. Zhang; W. Zhang; W. C. Zhang; W. Z. Zhang; Y. Zhang; Yue Zhang; Y. F. Zhang; Y. J. Zhang; Z. Zhang; Zhi Zhang; Z. L. Zhang; D. K. Zhou; J. F. Zhou; Y. Zhu; Y. X. Zhu; R. L. Zhuang
• Keywords: High Energy Astrophysical Phenomena (astro-ph.HE); FOS: Physical sciences; Astrophysics - High Energy Astrophysical Phenomena; Astrophysics - Instrumentation and Methods for Astrophysics; Instrumentation and Methods for Astrophysics (astro-ph.IM)

Fast radio bursts (FRBs) are short pulses observed in radio band from cosmological distances. One class of models invoke soft gamma-ray repeaters (SGRs), or magnetars, as the sources of FRBs. Some radio pulses have been observed from some magnetars, however, no FRB-like events had been detected in association any magnetar burst, including one giant flare. Recently, a pair of FRB-like bursts (FRB 200428 hereafter) separated by milliseconds (ms) were detected from the general direction of the Galactic magnetar SGR J1935+2154. Here we report the detection of a non-thermal X-ray burst in the 1-250 keV energy band with the Insight-HXMT satellite, which we identify as emitted from SGR J1935+2154. The burst showed two hard peaks with a separation of 34 ms, broadly consistent with that of the two bursts in FRB 200428. The delay time between the double radio and X-ray peaks is about 8.57 s, fully consistent with the dispersion delay of FRB 200428. We thus identify the non-thermal X-ray burst is associated with FRB 200428 whose high energy counterpart is the two hard peaks in X-ray. Our results suggest that the non-thermal X-ray burst and FRB 200428 share the same physical origin in an explosive event from SGR J1935+2154.<br/>24 pages, 9 figures, 6 tables; initial submission to a journal on May 9th, 2020. Significant changes include updated localization and detailed spectral evolution of the X-ray burst, and better determination of the two narrow X-ray peaks corresponding to the two radio pulses. Conclusions are strengthened. Nature Astronomy online on Feb. 18, 2021<br/>