Abstract
We analysed Dixon's Master List of Radio Sources and four large radio surveys for a concentration of sources towards the centres of Abell clusters of galaxies. Using all radio sources, regardless of optical identification, we find that at all frequencies the amount of concentration increases strongly with increasing flux density. The density enhancement of sources within 0.1 Abell radii ranges from 3 to 10 above background for the analysed surveys, but rises to about 20 for all of them, when only strong sources are considered. The richer (R>=2) clusters show the highest concentration of sources above background and generally a broader distribution, while the early Bautz-Morgan types (BM < II) show the narrowest one. Often a source deficiency relative to the survey mean is found in the cluster peripheries.
