Chandra’s image shows two large central galaxies, NGC 4889 (left) and NGC 4874 (right), embedded in a vast 100 million-degree Celsius gas cloud that pervades the cluster. Of particular interest are the concentrations of cooler (10 to 20 million-degrees) gas around these galaxies. The clumps of gas, which are 10,000 light years in diameter, are thought to have been produced by matter ejected from stars in the galaxies over a period of about a billion years. The clouds‘ temperature is thought to be maintained by a delicate balance between energy lost by X-radiation and energy gained by heat conduction from the hot gas of the cluster.