Fermi/GBM Observations of SGR J0501+4516

摘要

The magnetar candidate SGR J0501+4516 was discovered when it became active for about 13 days from August 22 to September 3, 2008. During this period, the Gamma-ray Burst Monitor (GBM) onboard Fermi detected over 30 bursts. We present here our results on the temporal and spectral analysis of the 29 bursts for which high spectral and time resolution data is available. We find that the T_(90) durations of the bursts follow a log-normal distribution with a mean value of approx123 ms. We fit the time-integrated spectrum of each burst with several models: a black body function, optically thin thermal brehmsstrahlung, a power law with an exponential cut-off, two black body functions, and the combination of a black body and a power law. We discuss our results in the context of the spectral properties of other magnetar bursts and we also present some correlations between the spectral parameters of the best fit models for all bursts. Finally, we present the results of our time-resolved spectral analysis of the five brightest bursts and discuss how they compare with our time-integrated results.