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How Do Fossil Galaxy Clusters Form so Quickly? - Universe Today
Fossil galaxy cluster as observed by XMM-Newton. Image credit: ESA. Click to enlarge Galaxies start small, but grow over time as they merge with other galaxies. After a while, however, the nearby space runs out of galaxies to merge with. All that’s left is one large galaxy called a fossil group, which sits inside an … Continue reading "How Do Fossil Galaxy Clusters Form so Quickly?"