Three hundred twenty million light-years distant, the Perseus Cluster contains thousands of galaxies, but none of them are seen here. Instead of mere galaxies, a fifty million degree cloud of intracluster gas , itself more massive than all the cluster's galaxies combined, dominates the x-ray view . From this angle, voids and bright knots in the x-ray hot gas cloud lend it a very suggestive appearance . Like eyes in a skull, two dark bubbles flank a bright central source of x-ray emission. The bright x-ray source is likely a supermassive black hole at the cluster center with the bubbles blown by explosions of energetic particles ejected from the black hole and expanding into the immense gas cloud.
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