Radio Sources in Clusters of Galaxies

Abstract

Fifty-eight clusters from Abell's catalogue have been examined for radio emission using the Arecibo l000 ft reflector and the Molonglo 1 mile Cross. The positions, sizes, and flux densities at 408 MHz of 30 radio sources close to these clusters have been measured. Nineteen of these offer reasonable identifications with galaxies or blue stellar objects. Thirteen appear to be identifiable with individual cluster galaxies. No evidence for integrated cluster emission has been obtained. It has been concluded that either the centroid of radio sources may sometimes be well displaced from the parent galaxies or, in a significant number of cases, the only detectable radio source in a cluster is associated with a faint cluster galaxy, not a giant.