This image of galaxy cluster MS 0735.6+7421 was taken by the Chandra X-ray Observatory in November 2003. Diffuse, hot gas with a temperature of nearly 50 million degrees permeates the space between the galaxies in the cluster. The gas emits X-rays, which are seen as blue in this image. Enormous holes or cavities in the gas, each roughly 640,000 light-years in diameter - nearly seven times the diameter of the Milky Way are seen in the image. The cavities were created by jets of charged particles ejected at nearly light speed from a supermassive black hole weighing nearly a billion times the mass of our Sun, which lurks in the nucleus of the bright central galaxy.
Credit: NASA/CXC, B. McNamara (University of Waterloo and Ohio University)