Further Studies of Clusters of Galaxies Using Rosat All-Sky Survey Data

摘要

This work has concentrated on the description of substructure in nearby clusters from PSPC observations. It has included the definitive proof that the Coma cluster is not virialized. This cluster was the prototype of a rich relaxed cluster. Previous work had hinted that it had not yet virialized but the discovery of a group merging with the cluster sealed the argument. The first fully two dimensional temperature maps of clusters of galaxies have also been produced. These maps demonstrate that temperature structure is an extremely good way to elucidate the dynamical state of a cluster. For example, the temperature map of the Coma cluster shows that the merging group has passed through the cluster already, contrary to the initial interpretation or the data. Although these temperature maps can only be made for a few massive clusters with the PSPC, they are the first and they will help to understand the maps from ASCA which has different systematic effects. Future work will concentrate on measuring the structure of a sample of distant clusters using HRI observations.