The Stellar Composition of X-Ray Surveys from the Einstein Observatory
Abstract
A new class of X-ray-luminous 'yellow' stellar objects which contributes significantly to the stellar log N-log S distribution, but which cannot be reconciled with normal G and K main-sequence stars. This identification results from a new analysis of the stellar content of three samples of X-ray-selected X-ray sources observed with the Einstein Observatory, namely the 'Medium Sensitivity Survey', the 'High Sensitivity Survey', and the 'Hyades Region Survey'. In this paper, both X-ray and optical properties of the stellar samples in these surveys are reported. The actual stellar content of the surveys is compared with predictions based on current knowledge of stellar X-ray luminosity functions and the stellar composition and spatial distribution in the Galaxy. It is shown that a plausible identification for the excess population of 'yellow' stars is with the active, RS CVn-like binaries.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- January 1988
- DOI:
- 10.1086/165957
- Bibcode:
- 1988ApJ...324.1010F
- Keywords:
-
- Sky Surveys (Astronomy);
- Statistical Analysis;
- Stellar Composition;
- Stellar Luminosity;
- X Ray Binaries;
- Exosat Satellite;
- G Stars;
- Heao 2;
- K Stars;
- Optical Properties;
- Astrophysics;
- STARS: BINARIES;
- X-RAYS: SOURCES