The contributions of RS CVn systems to the diffuse X-ray background.
Abstract
We present comprehensive calculations of the contribution of RSCVn binaries to the diffuse X-ray background. We consider luminosity distribution functions derived from both optically selected volume-limited and X-ray selected flux-limited samples, use the Bahcall-Soneira galaxy model to describe the spatial distribution of stars in the Galaxy, and take into account anisotropic absorption by the interstellar medium. Our principal results are that RSCVn binaries provide approximately 16 percent to the observed low-latitude background at intermediate X-ray energies, while in the 2-6 keV band their contribution to the total background amounts to about 6 percent, which however represents about a 27 percent contribution to the Galactic ridge excess emission. This additional stellar component thus helps to fill up the absorption dip in the extragalactic background produced by absorption in the Galaxy and to isotropize the total M band background. However, our models of RSCVn systems are unable to account for the iron line observed in the Galactic ridge.
- Publication:
-
Astronomy and Astrophysics
- Pub Date:
- March 1992
- Bibcode:
- 1992A&A...256..421O
- Keywords:
-
- Background Radiation;
- Cosmic X Rays;
- Eclipsing Binary Stars;
- F Stars;
- K Stars;
- Astronomical Models;
- Stellar Coronas;
- Stellar Luminosity;
- Stellar Temperature;
- X Ray Spectra;
- Space Radiation