The dependence of radio galaxy luminosity and size on cluster membership

The dependence of radio luminosity and source size on cluster membership is considered for a sample of 71 double and triple radio sources. Two methods are employed for cluster classification; one based on the Abell and Zwicky catalogues and the other directly on the number of galaxies in the neighbourhood of each source. The latter approach has the advantage of being relatively free of distance-dependent selection effects as well as being sensitive to source placement within a cluster and to subclustering effects. The incompletenesses in published catalogues of clusters, in particular the Zwicky catalogue, introduce significant selection effects that preclude their use as the sole means of determining the cluster status of sources. (author)