RX J2217.9--5941: A highly X-ray variable Narrow-Line Seyfert1 galaxy
Abstract
We report the discovery of a highly X-ray variable AGN, RX J2217.9-5941. This object was bright during the ROSAT All-Sky Survey (RASS), during which a decrease in the count rate by a factor of 12 was observed. It was found to be much fainter in follow-up HRI observations and is therefore an X-ray transient AGN candidate. On long time scales of years, its count rate decreased by a factor of about 30 between the RASS and the ROSAT HRI and ASCA observations in 1998. Analysis of the ASCA data, complicated by source confusion and poor statistics, tentatively indicates a steep spectrum in the faint state. There is no evidence for variability among 5 optical observations of the object obtained between 1992 and 1998. We discuss the variability of RX J2217.9-5941 and its possible X-ray transient nature.
Cite
@article{arxiv.astro-ph/0101410,
title = {RX J2217.9--5941: A highly X-ray variable Narrow-Line Seyfert1 galaxy},
author = {D. Grupe and H. -C. Thomas and K. M. Leighly},
journal= {arXiv preprint arXiv:astro-ph/0101410},
year = {2009}
}
Comments
10 pages (including 7 Figures), accepted for A&A, also available at http://www.xray.mpe.mpg.de/~dgrupe/research/refereed.html