(galaxy with an active, i.e., extremely luminous central region)
An active galaxy is a
galaxy whose central region has a very high luminosity.
Such excess emission has been observed in radio,
infrared, visible light, X-ray, and gamma rays
bands. The nucleus is called an active galactic nucleus (AGN).
The radiation is assumed to be due to accretion of mass
by a supermassive black hole. Often associated with such a
nucleus is a relativistic jet.
active galactic nucleus (AGN)
Canadian Institute for Theoretical Astrophysics (CITA)
Extended Chandra Deep Field-South Survey (ECDFS)
radio galaxy (RG)