This glowing purple cloud may look stunning, but you wouldn't want to get too close—because it's actually a multi-million degree celsius gas cluster.
This composite images, stitched together from data acquired by NASA’s Chandra X-ray Observatory and ESA’s XMM-Newton, shows enormous arms of hot gas in the Coma cluster of galaxies. Spanning at least half a million light years, the hot gas spans the entire field of view.
NASA researchers believe that the arms were probably formed when smaller galaxy clusters had their gas stripped away by the head wind created by the motion of the cluster through the hot gas. [NASA]
Image bt NASA/CXC/MPE/J. Sanders et al