The Dynamics of the cD Clusters Abell 119 and Abell 133

Abstract

A dynamical analysis of the structure of the clusters of galaxies Abell 119 and Abell 133 is presented, using new redshift data combined with existing data from the literature. We compare our results with those from the X-ray data for these clusters, and with those from radio data for the central cD galaxy in each cluster. A comparison of the mass estimate based on X-ray data and that obtained here after subgroups are eliminated shows them to be comparable. After the elimination of subgroups, 125 galaxy members in Abell 119 and 120 in Abell 133 give dispersions of 472 km/s and 735 km/s respectively. However, our dynamical analysis of the optical data shows little substructure in the velocity field of Abell 133, conflicting with what is seen in the Rosat X-ray map. Abell 119 seems to have multiple structures along the line of sight. We derive virial mass estimates of 3.05 X 10E14 Solar Masses for Abell 119 and 7.79 X 10E14 Solar Masses for Abell 133 within 1.5 Mpc, which agree well with the X-ray-derived masses within errors.