This Chandra image is colorized to highlight a population of point-like "ultraluminous" X-ray sources in M82, a starburst galaxy 11 million light-years from Earth.
Red represents the low-energy band, green intermediate, and blue the highest observed energies. The white and yellow sources are those that emit significant amounts of both low- and high-energy X-rays.
The ultraluminous sources, which emit 10 to several hundred times more X-ray power than similar sources in our Galaxy, are believed to be either massive black holes, or black holes that are beaming energy toward Earth. The brightest point-like source, located near the center of the image, is the most powerful ultraluminous source detected in any galaxy to date.