The Radio Properties of CD Galaxies in Abell Clusters. II. The VLA Sample

The radio properties of a sample of 91 cD galaxies in Abell clusters are presented. The radio data consist of new 6 cm VLA maps with a resolution of 1"-2" as well as data from the literature. The principal goal of this project was to investigate the possible effects of global and local cluster properties on the radio properties of cDs. The dominant predictor of central radio activity is the presence of x-ray cooling flows, as reported in Paper I [Burns, J. O., AJ, 99, 14(1990)]. Results described in this paper indicate a slight increase in the detection rate and a steeper spectral index for cDs in Bautz-Morgan (B-M) I clusters in comparison to clusters having any other B-M type. Cluster richness and cD absolute magnitude seem to be uncorrelated with radio power. However, there is a possible weak correlation of radio power with the ellipticity of the cD at 16 kpc from the galaxy's optical center. The radio morphological types of the detected galaxies are related to radio- luminosity and spectral index with compact radio sources being most often detected. Steep-spectrum, amorphous sources are a peculiar class of radio source associated exclusively with dominant galaxies in cooling flows. Finally, a 6 cm radio luminosity function (RLF) is computed for cDs and compared to the RLF for cluster galaxies in general. Interestingly, the slope of the RLF below the knee is flatter than that for other cluster ellipticals, possibly reflecting the unique environment and evolution of cDs.