Two Hard X-Ray Sources in the Central Region of the Virgo Cluster
Abstract
We have detected two hard X-ray sources: the giant elliptical galaxy M87 and the Seyfert 2 galaxy NGC 4388 in the central region of the Virgo cluster of galaxies. The brighter source is NGC 4388, which has a power-law spectrum with a photon index of about 1.3 and a 10--20 keV luminosity of (2.0 +/- 0.2) times 10(42) erg s(-1) . M87, the second source, has a larger photon index than does NGC 4388, and its luminosity was estimated to be (6.9 +/- 1.2) times 10(41) erg s(-1) in the 10--20 keV band. No other point source nor diffuse hard X-ray emission larger than 1(deg) was found.
- Publication:
-
Publications of the Astronomical Society of Japan
- Pub Date:
- February 1991
- Bibcode:
- 1991PASJ...43....1T
- Keywords:
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- Elliptical Galaxies;
- Seyfert Galaxies;
- Virgo Galactic Cluster;
- X Ray Sources;
- Active Galactic Nuclei;
- Luminosity;
- X Ray Spectra;
- Astrophysics;
- CLUSTERS OF GALAXIES;
- SEYFERT GALAXIES;
- X-RAY SOURCES;
- X-RAY SPECTRA