Statistical Properties of X-Ray Bursts from SGR J1935+2154 Detected by Insight-HXMT

TL;DR

This study analyzes the statistical properties of 75 X-ray bursts from magnetar SGR J1935+2154, revealing power-law distributions consistent with self-organizing criticality, across different energy bands, supporting a magnetic reconnection origin.

Contribution

It applies power-law modeling to burst distributions, confirming self-organizing criticality in magnetar X-ray bursts and exploring energy band invariance, which advances understanding of burst mechanisms.

Findings

Power-law distributions fit the burst parameters well.

No significant evolution of distributions across energy bands.

Supports magnetic reconnection as the burst origin.

Abstract

As one class of the most important objects in the universe, magnetars can produce a lot of different frequency bursts including X-ray bursts. In \cite{2022ApJS..260...24C}, 75 X-ray bursts produced by magnetar SGR J1935+2154 during an active period in 2020 are published, including the duration and net photon counts of each burst, and waiting time based on the trigger time difference. In this paper, we utilize the power-law model, $dN(x)/dx\propto (x+x_0)^{-\alpha_x}$, to fit the cumulative distributions of these parameters. It can be found that all the cumulative distributions can be well fitted, which can be interpreted by a self-organizing criticality theory. Furthermore, we check whether this phenomenon still exist in different energy bands and find that there is no obvious evolution. These findings further confirm that the X-ray bursts from magnetars are likely to be generated by some self-organizing critical process, which can be explained by a possible magnetic reconnection scenario in magnetars.