Clumped X‐ray emission around radio galaxies in clusters: New tools for investigating cluster evolution

New ROSAT X‐ray imaging of clusters with extended radio galaxies is described. We present evidence for a strong correlation between the positions of radio galaxies and clumped X‐ray emission within galaxy clusters. This correlation is interpreted as the result of mergers between clusters. We argue that radio galaxies are good probes of the dynamical state of clusters. In particular, wide‐angle tailed radio sources may be the best tool that presently exists for sampling large‐scale gas motions in clusters which have undergone mergers. We also present hybrid Hydro/N‐body simulations of cluster mergers which show that (1) cluster gas cores are heated via shocks, (2) cooling cores are likely destroyed during mergers, (3) bulk gas motions of ≊1000 km/s persist for about 5 Gyr following the mergers, and (4) the intracluster gas may not be in hydrostatic equilibrium for clusters with significant X‐ray substructure.