Observations of Compact X-Ray Sources

Abstract

This paper reviews the present status of observations of compact X-ray sources with emphasis on the aspects related to radiation hydrodynamics, based on the recent observational results, in particular those from the Japanese X-ray astronomy satellite Tenma. The main feature of Tenma is a large-area gas scintillation proportional counters (GSPC) with energy resolution twice that of ordinary proportional counters, which can yield information on energy spectrum superior in quality to previous results. We shall deal here only with those galactic X-ray sources in which the compact object is a neutron star or possibly a black hole, and exclude white dwarf sources. There exist more than one hundred bright X-ray sources in our galaxy in the luminosity range 10 36 −10 38 ergs/sec. They are most probably binaries involving a neutron star or, in some cases, possibly a black hole. The high luminosities of these sources are explained in terms of the large gravitaional energy release by matter accreting from the companion star to the compact object.