Identification of the sigma source near 3C 273 : a new class of AGN ?
Abstract
The hard X-ray source detected with SIGMA at an offset of ~15' from 3C 273 may be identified with an uncatalogued Einstein X-ray source detected in the deep Einstein HRI exposure of 3C 273 and in subsequent short IPC exposures. We have identified this source, within the SIGMA error circle, with a faint (mag 19-20) QSO at z = 0.57. Comparison of the SIGMA and Einstein fluxes with this optical object suggest it is highly self-absorbed, and possibly highly variable. The discovery of such a class of AGN would have important consequences for the cosmic X-ray background.
- Publication:
-
Astronomy and Astrophysics Supplement Series
- Pub Date:
- January 1993
- Bibcode:
- 1993A&AS...97..113G
- Keywords:
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- Active Galactic Nuclei;
- Quasars;
- X Ray Sources;
- Astronomical Spectroscopy;
- Background Radiation;
- Rosat Mission;
- Spaceborne Astronomy;
- X Ray Spectra;
- Astronomy