Cygnus X-3 at very high energies

Abstract

Abstract Cyg X-3 is a well-known binary system which also belongs to a microquasar-type objects. It is actively studied through the wide range of electromagnetic spectrum including ultrahigh energies. Here, we present the results of more than 20-year-long studies of Cyg X-3 in the range of 800 GeV-100 TeV with the SHALON telescope. The detected TeV γ-ray source was identified with Cyg X-s based on the detection of the γ-ray flux modulation at the orbital period of this binary system of 4.8 hours. Detected modulation of TeV γ-ray emission with orbit together with the high luminosity of the companion star of Cyg X-3 and the close orbit leads to an efficient generation of the part of γ-ray emission in the inverse Compton scattering. The correlation of TeV flux increases with the flaring activity of Cyg X-3 at X-ray and radio ranges is found which could be associated with powerful mass ejections from the central regions around the black hole.