NICER Magnetar Burst Catalog

TL;DR

This paper presents a comprehensive catalog of 1130 magnetar bursts observed over eight years by NICER, analyzing their properties and correlations to advance understanding of magnetar burst mechanisms.

Contribution

The study provides the first extensive catalog of NICER-detected magnetar bursts, including the discovery of microsecond-scale bursts and detailed spectral and duration analyses.

Findings

SGR 1935+2154 bursts are longer than others, peaking at 316 ms.

First detection of microsecond-scale bursts from two sources.

Bursts with higher fluence tend to have harder spectra.

Abstract

In this paper, we present a comprehensive catalog of short bursts from magnetars based on eight years of NICER observations. A total of 1130 bursts were identified from 14 sources, with the sample dominated by SGR 1935+2154, which accounts for 76% of all detected bursts. We analyzed burst durations, spectral properties, and their correlations across multiple sources. Bursts from SGR 1935+2154 exhibit significantly longer durations, with a distribution peak at 316 ms, compared to a peak of 23 ms for bursts from other magnetars. Two {\mu}s-scale bursts were detected for the first time, originating from 1E 1048.1-5937 and CXOU J010043.1-721134. Spectral analysis in the 0.5-8 keV range using both blackbody and power-law models shows that bursts with higher fluences have harder spectra. In contrast, correlations between burst duration and spectral parameters are weak or absent. This catalog provides a valuable dataset for studying magnetar short bursts, enabling future modeling efforts and improving our understanding of the diversity and physical mechanisms of magnetar bursts.