Cosmic X-ray Sources, Galactic and Extragalactic

Abstract

Instruments carried aboard an Aerobee rocket in April 1965 provided evidence for x-ray emission from the directions of the radio galaxies Cygnus A and M-87 and from the galactic supernova remnant Cassiopeia A. A survey of the Cygnus region revealed a marked decrease in the flux of x-rays from Cygnus XR-1, which was identified in June 1964 as the second brightest object in the first Naval Research Laboratory list of x-ray sources. The detection sensitivity was improved over previous surveys and several new sources were detected at lower flux levels.