HEAO 1 high energy X-ray observations of the Virgo cluster and A 2142.
Abstract
Observations are reported of the Virgo cluster and Abell 2142 in the energy range of 15-150 keV, detected by using hard X-ray and low energy gamma-ray instruments on board the HEAO-1 spacecraft, during 1977 and 1978. The Virgo cluster was detected at a mean flux of (1.3 + or - 0.3) x 10 to the 0.001 photons/sq cm-s in the 20-100 keV band, and A2142 was detected marginally at a flux of (2 + or - 0.8) x 10 to the 0.001 photons/sq cm-s in the 15-40 keV band. Inverse Compton emission was not observed in these clusters. Results are used to derive limits to the intracluster magnetic field of B approximately greater than 5 x 10 to the -7th gauss and B approximately 5 x 10 to the -8th gauss in the Virgo cluster and A1242, respectively. There is some evidence for variability in these sources, which implies that the hard X-ray emission originates in a relatively compact object or region rather than from the cluster as a whole.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- June 1981
- DOI:
- 10.1086/158934
- Bibcode:
- 1981ApJ...246..369L
- Keywords:
-
- Heao 1;
- Intergalactic Media;
- Interstellar Magnetic Fields;
- Virgo Galactic Cluster;
- X Ray Sources;
- Galactic Nuclei;
- Galactic Radiation;
- Oso-8;
- Photons;
- Spaceborne Astronomy;
- Thermal Radiation;
- Variability;
- X Ray Spectra;
- Astrophysics