In these images of two merging galaxy clusters known as Abell 2146, X-rays from Chandra show hot gas while optical data from the Subaru telescope in Hawaii reveal individual galaxies. One cluster is moving towards the bottom left and plowing through the other cluster. The hot gas in the former is pushing out a shock wave, like a sonic boom generated by a supersonic jet, as it collides with the hot gas in the other cluster. A study shows a deep connection between this galaxy cluster collision — which is among the largest, most energetic events in the Universe — and much smaller, weaker ones powered by our own Sun.

A version of the X-ray image that has been processed to emphasize sharp features. The hot gas in galaxy cluster #2 is pushing out a shock wave, like a sonic boom generated by a supersonic jet, as it collides with the hot gas in galaxy cluster #1. Also labeled are the central core of hot gas in cluster #2, and the tail of gas it has left behind. A second shock wave of similar size is seen behind the collision. Called an "upstream shock," features like this arise from the complex interplay of stripped gas from the infalling cluster and the surrounding cluster gas.