Structure of the X-ray source in the Virgo cluster of galaxies.
Abstract
High-angular-resolution observations in the 0.15-1.5-keV band with an imaging X-ray telescope shows the extended X-ray source in the Virgo cluster of galaxies to be a diffuse halo of about 15 arcmin core radius surrounding M87. The angular structure of the surface brightness is marginally consistent with either of two simple models: (1) an isothermal (or adiabatic or hydrostatic) sphere plus a point source at M87 accounting for 12% of the total 0.5-1.5-keV intensity or (2) a power-law function without a discrete point source. No evidence for a point source is seen in the 0.15-0.28-keV band, which is consistent with self-absorption by about 10 to the 21st power per sq cm of matter having a cosmic abundance. The power-law models are motivated by the idea that radiation losses regulate the accretion of matter onto M87 and can account for the observed difference in the size of the X-ray source as seen in the present measurements and at higher energies.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- September 1977
- DOI:
- 10.1086/182519
- Bibcode:
- 1977ApJ...216L..95G
- Keywords:
-
- Astronomical Models;
- Galactic Clusters;
- Galactic Structure;
- X Ray Sources;
- Angular Resolution;
- Brightness;
- Emission Spectra;
- Point Sources;
- Radiant Flux Density;
- Spaceborne Astronomy;
- Astrophysics