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 SGR1900+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 s long X-ray afterglow following the April 2001 intermediate flare. In the latter case, we explore the possibility of describing the observed short term spectral evolution only with a change of the temperature of the blackbody component. In the only BeppoSAX observation performed before the giant flare, the spectrum of the SGR1900+14 persistent emission was significantly harder and detected also above 10 keV with the PDS instrument. In the last BeppoSAX observation (April 2002) the flux was at least a factor 1.2 below the historical level, suggesting that the source was entering a quiescent period.
Keywords
Cite
@article{arxiv.astro-ph/0609319,
title = {Long term spectral variability in the Soft Gamma-ray Repeater SGR 1900+14},
author = {A. Tiengo and P. Esposito and S. Mereghetti and L. Sidoli and D. Goetz and M. Feroci and R. Turolla and S. Zane and G. L. Israel and L. Stella and P. Woods},
journal= {arXiv preprint arXiv:astro-ph/0609319},
year = {2015}
}
Comments
4 pages, 3 figures. To be published in the proceedings of the conference "Isolated Neutron Stars: from the Interior to the Surface", London, April 2006; eds. D. Page, R. Turolla, & S. Zane