The Colossus in Coma
Enormous arms of hot gas in the Coma cluster of galaxies were found using NASA’s Chandra X-ray Observatory and ESA’s XMM-Newton. These features, which span at least half a million light years, provide insight into how the cluster has grown through mergers of smaller groups of galaxies to become one of the largest structures in the universe held together by gravity. Chandra data is in pink, and that from the Sloan Digital Sky Survey is white and blue. –X-ray: NASA/CXC/MPE/J. Sanders et al; Sloan Digital Sky Survey