An Insight-HXMT Dedicated 33 day Observation of SGR J1935+2154. II. Burst Spectral Catalog

Abstract Since 2020 April 28, Insight-HXMT has implemented a dedicated observation on the magnetar SGR J1935+2154. Thanks to wide energy band (1–250 keV) and high sensitivity of Insight-HXMT, we obtained 75 bursts from J1935+2154 during month-long activity episode after emission FRB 200428. Here report detailed time-integrated spectral analysis these statistical distribution parameters. We find that for ∼15% (11/75) bursts, CPL model is preferred, most them occurred in later part this active epoch. In cumulative fluence distribution, our sample about an order magnitude weaker than Fermi/GBM, but it follows same power-law distribution. Finally, burst with similar peak spectrum X-ray associated 200428 (FRB 200428-Associated Burst), low index harder.