Gamma-Ray Emission in MeV--GeV Region from Cygnus X-3

Abstract

The analysis of the simultaneous X-ray and gamma-ray observations of Cygnus X-3 by the ESA satellite COS B indicates that there exists a negative correlation between intensities of 2-12 keV X-rays and 150-5000 MeV gamma rays of Cygnus X-3. A clear image of a gamma-ray source at the position of Cygnus X-3 is obtained from the spatial distribution of gamma-ray photons incident when Cygnus X-3 was in a low X-ray state between June 1977 and June 1980, and the correspondent gamma-ray flux of Cygnus X-3 is derived as F(E greater than 100 MeV) = (1.3 + or - 0.6) x 10 to the -6th per sq cm s.