Stellar composition of X-ray surveys from the Einstein Observatory

Journal Article · Fri Jan 01 04:00:00 EST 1988 · Astrophys. J.; (United States)

DOI:https://doi.org/10.1086/165957· OSTI ID:5339826

Favata, F; Sciortino, S; Rosner, R; Vaiana, G S

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. 24 references.

• Research Organization: Osservatorio Astronomico, Palermo (Italy); Chicago Univ., IL (USA); Harvard-Smithsonian Center for Astrophysics, Cambridge, MA (USA)
• OSTI ID: 5339826
• Journal Information: Astrophys. J.; (United States), Journal Name: Astrophys. J.; (United States) Vol. 324; ISSN ASJOA
• Country of Publication: United States
• Language: English

Related Subjects

640102* -- Astrophysics & Cosmology-- Stars & Quasi-Stellar
Radio & X-Ray Sources
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
BINARY STARS
CHEMICAL COMPOSITION
COSMIC RAY SOURCES
COSMIC X-RAY SOURCES
ELECTROMAGNETIC RADIATION
IONIZING RADIATIONS
LUMINOSITY
MATHEMATICS
OPTICAL PROPERTIES
PHYSICAL PROPERTIES
RADIATIONS
STARS
STATISTICS
SURVEYS
X RADIATION