The dynamics of the cluster of galaxies A 2029.

Redshifts have been determined for 31 additional galaxies in the rich cluster A2029. The velocity dispersion, based on 47 members, is found to be ΔV = 1430 km s^-1. The result implies a high M/L_V ∼ 500. Correlations of X-ray luminosity and temperature with velocity dispersion in rich clusters are strengthened by the high ΔV.

Many of the galaxies which appear projected against the cD envelope have large velocities relative to the cD, indicating that they are not being cannibalized. This is consistent with the expectation that few victims could be seen at any one time, as a result of the short time scale for their consumption.

The cluster, which is highly flattened, shows no signs of large-scale rotation. Models are constructed and statistically tested which show that the flat distribution is not likely to be supported by rotation, but rather reflects an anisotropic velocity field. Cannibalism by the cD of galaxies in the anisotropic field might account for the flattening of the cD envelope and its alignment to the cluster.