2001/05/07 by Ersin Gogus, Chryssa Kouveliotou, Peter M. Woods +3 · 1 citation
Physics and Astronomy · #astro-ph
paper · pdf · doi:10.1086/322463
24 pages, 11 figures, accepted for publication in ApJ
arxiv created 2001/05/07 · arxiv updated 2009/12/01
We study the temporal and coarse spectral properties of 268 bursts from SGR 1806-20 and 679 bursts from SGR 1900+14, all observed with the Rossi X-Ray Timing Explorer/Proportional Counter Array. Hardness ratios and temporal parameters, such as T90 durations and tau90 emission times are determined for these bursts. We find a lognormal distribution of burst durations, ranging over more than two orders of magnitude: T90 ~ 10-2 to >~ 1 s, with a peak at ~ 0.1 s. The burst light curves tend to be asymmetrical, with more than half of all events showing rise times tr < 0.3 T90. We find that there exists a correlation between the duration and fluence of bursts from both sources. We also find a significant anti-correlation between hardness ratio and fluence for SGR 1806-20 bursts and a marginal anti-correlation for SGR 1900+14 events. Finally, we discuss possible physical implications of these results within the framework of the magnetar model.