X-ray variability in a complete sample of Soft X-ray selected AGN
Abstract
We present ROSAT All-Sky Survey and ROSAT pointed observations (PSPC and HRI) of a complete sample of 113 bright soft X-ray AGN selected from the ROSAT Bright Source Catalog. We compare these observations in order to search for extreme cases of flux and spectral X-ray variability - X-ray transient AGN. Three definite transients and one transient candidate are found. The other sources show amplitude variations typically by factors of 2-3 on timescales of years. We found that the variability strength on timescales of days is a function of the steepness of the X-ray spectrum: steeper X-ray objects show stronger variability than flat X-ray spectrum sources. We also present new HRI measurements of our extreme X-ray transients IC 3599 and WPVS007. We discuss possible models to explain the X-ray transience and the variabilities observed in the non-transient sources.
Keywords
Cite
@article{arxiv.astro-ph/0012100,
title = {X-ray variability in a complete sample of Soft X-ray selected AGN},
author = {D. Grupe and H. -C. Thomas and K. Beuermann},
journal= {arXiv preprint arXiv:astro-ph/0012100},
year = {2016}
}
Comments
17 pages (including 7 Figures), accepted for in A&A (main journal), also available at http://www.xray.mpe.mpg.de/~dgrupe/research/refereed.html