Long term spectral variability in the soft gamma ray repeater SGR 1900+14
Abstract
We present a systematic analysis of all the BeppoSAX data of SGR 1900+14. The observations spanning five years show that the source was brighter than usual on two occasions: ~20 days after the August 1998 giant flare and during the 10^5 sec long X-ray afterglow following the April 2001 intermediate flare. In the latter case, we explore the possibility of describing the observed short term softening only with a change of the temperature of a blackbody-like component. In the only BeppoSAX observation performed before the giant flare, the spectrum of the SGR 1900+14 persistent emission was significantly harder and possibly detected also above 10 keV with the PDS instrument. In the last BeppoSAX observation (April 2002) the flux was ~25 % lower than the historical level, suggesting that the source was entering a quiescent period.
Cite
@article{arxiv.astro-ph/0612787,
title = {Long term spectral variability in the soft gamma ray repeater SGR 1900+14},
author = {P. Esposito and S. Mereghetti and A. Tiengo and D. Goetz and L. Sidoli and M. Feroci},
journal= {arXiv preprint arXiv:astro-ph/0612787},
year = {2008}
}
Comments
Proceedings of the 363. WE-Heraeus Seminar on: Neutron Stars and Pulsars (Posters and contributed talks) Physikzentrum Bad Honnef, Germany, May.14-19, 2006, eds. W.Becker, H.H.Huang