NICER Magnetar Burst Catalog

Che-Yen Chu^1*, Chin-Ping Hu¹, the NICER Magnetar and Magnetosphere team¹

¹Department of Physics, National Chunghua University of Education, Changhua, Taiwan

* Presenter:Che-Yen Chu, email:jck37330@gmail.com

We present a comprehensive catalog of magnetar bursts detected with NICER, aimed at characterizing their temporal and spectral properties. This study includes all available NICER observations of known magnetars and two magnetar-like rotation-powered pulsars, spanning eight years of data and totaling 6000 ks of exposure. Using the Bayesian blocks algorithm, we systematically searched for rapid flux variations in the light curves and identified 1133 bursts. Benefiting from NICER’s large effective area and high timing resolution, we performed detailed timing and spectral analyses to measure key burst parameters, including the T90 duration, fluence, and flux. We identified two bursts with extremely short durations and several exceptionally soft bursts, which may originate from distinct emission mechanisms. By examining the parameter distributions and correlations, we explored relationships among burst properties. Furthermore, we compared burst characteristics across different magnetars and magnetar-like pulsars and found that bursts from SGR 1935+2154 differ significantly from those of other sources. This catalog provides a valuable resource for investigating magnetar burst behavior, offering insights into burst triggering mechanisms and magnetospheric dynamics.

Keywords: Magnetar, Neutron star, X-ray trainsient, NICER