An Etymological Dictionary of Astronomy and Astrophysics

An astronomical object whose dominant mechanism of radiation is through X-ray emission. X-ray sources contain an extremely hot gas at temperatures from 10⁶ to 10⁸ K. They are generated by various physical processes involving high energies, such as accretion on to a compact object, shock waves from
supernovae, stellar winds, hot gas in stellar coronae, or hot spaces between galaxies in a cluster. The first celestial X-ray source, after the Sun, to be detected was → Scorpius X-1 by means of rocket flight (Giacconi et al. 1962).

See also: → X-ray; → source.