From its x-ray emission map, M82 appears as a bright, compact core with fainter emission extending around it. X-rays originate in processes involving high tempera- tures of a million or more degrees Kelvin. The bright center of M82, which is more energetic than the centers of many other galaxies, is probably caused by the combination of thousands or even millions of individual sources, including giant stars and remnants produced in supernova explosions. Such strong x-ray emission suggests that the center of this galaxy has played host to a massive burst of star formation, a conclusion supported by radio observations.
M82ΓÇÖs x-ray emission is evidently not confined to the center of the galaxy. The envelope of emission
