X-ray source

An X-ray source is an object, or a location in the celestial sphere from which X-rays are detected. The term X-ray source avoids interpretation (i.e., any declaration what kind of object is producing the X-rays), though it is often used even when a certain type of source is assumed. X-ray astronomy began in full with the development of X-ray space observatories. Example sources:

• supermassive black hole accretion (quasars, active galactic nuclei, Seyfert galaxies).
• other black hole accretion (microquasars).
• galaxy clusters (from intergalactic medium plasma).
• neutron stars (pulsars, magnetars).
• supernova remnants.

Shock and magnetic fields can be factors in producing the heat to produce discernible X-ray black-body radiation. Stars (e.g., the Sun) produce X-rays, such as that from the corona which includes plasma significantly hotter than the Sun's surface. X-ray is detected from some pre-main-sequence stars, some early stars, and some cool stars such as M dwarfs and brown dwarfs. Some classes of sources:

• hard X-ray source (HXR).
• soft X-ray source (SXR).
• ultraluminous X-ray source (ULX).