Three rich clusters of galaxies with bimodal or clumpy X-ray morphologies

X-ray images of the rich clusters of galaxies A1560, A2356, and A2384 show that the individual X-ray features correspond to hot gas of between one and 10 billion solar masses. These results are consistent with the formation of clusters by subcluster coalescence and merging. Clusters can be observed in almost any stage of coalescence, and it is recommended that galaxy motions and distributions be correlated with X-ray brightness distributions.