Energy spectra of 43 galactic X-ray sources observed by UHURU

Abstract

X-ray observations from the Uhuru satellite have been used to obtain the energy spectra from 2 to 20 keV for 43 galactic X-ray sources, which then were used to classify the X-ray sources. This survey has shown that galactic sources exhibit different spectra with a temperature range from 10 to the 7th to 2 x 10 to the 8th K. For the sources included in this survey no significant increase was observed in the number of sources with very cool temperatures or with very hot temperatures. Ten of the 11 X-ray sources which have been reported to pulsate regularly on time scales of seconds to minutes have temperatures exceeding about 10 to the 8th K. The four globular-cluster X-ray sources 3U 1820-30, 3U 1746-37, A1850 + 09, and MX 1746-20 have spectra similar to the strong galactic center sources with temperatures between 4 x 10 to the 7th and 9 x 10 to the 7th K.