This X-ray image of cluster RXCJ2337.6+0016, shows a cluster merger configuration in a very late stage. The two merging sub-clusters are dissolved in the new cluster but we still see a very complex entropy structure in the centre.

The blue irregular-shaped region in the centre has the low entropy of a cool cluster core. It was probably a stable, very symmetrical, cool and dense cluster core region that has now completely been disrupted by the cluster merger.