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. Bases in part on observations at the European Southern Observatory La Silla (Chile) with the ESO/MPG 2.2~m telescope, the ESO 1.52~m telescope in August 1992 and September 1995, and the ESO 3.6~m in January 2001.
- Publication:
-
Astronomy and Astrophysics
- Pub Date:
- April 2001
- DOI:
- 10.1051/0004-6361:20010117
- arXiv:
- arXiv:astro-ph/0101410
- Bibcode:
- 2001A&A...369..450G
- Keywords:
-
- ACCRETION;
- ACCRETION DISKS;
- GALAXIES: ACTIVE;
- GALAXIES: NUCLEI;
- GALAXIES: SEYFERT;
- GALAXIES: INDIVIDUAL (RX J2217.9-5941);
- Astrophysics
- E-Print:
- 10 pages (including 7 Figures), accepted for A&