Volume 369, Number 2, April II 2001
|Page(s)||450 - 458|
|Section||Cosmology (including clusters of galaxies)|
|Published online||15 April 2001|
RX J2217.9-5941: A highly X-ray variable Narrow-Line Seyfert1 galaxy *
MPI für extraterrestrische Physik, Postfach 1312, 85741 Garching, Germany
2 MPI für Astrophysik, Karl-Schwarzschild-Str. 1, 85748 Garching, Germany
3 Columbia Astrophysics Laboratory, 538 West 120th St., New York, NY 10027, USA
4 Dept. of Physics and Astronomy, University of Oklahoma, 440 W. Brooks St., Norman, OK 73019, USA
Corresponding author: D. Grupe, firstname.lastname@example.org
Accepted: 12 January 2001
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.
Key words: accretion, accretion disks / galaxies: active / galaxies: nuclei / galaxies: Seyfert / galaxies: individual (RX J2217.9 / 5941)
© ESO, 2001
Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.
Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.
Initial download of the metrics may take a while.