Astrophysics (Index)About

active galaxy

(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.

(galaxy type)
Further reading:

Referenced by pages:
active galactic nucleus (AGN)
Canadian Institute for Theoretical Astrophysics (CITA)
duty cycle
Extended Chandra Deep Field-South Survey (ECDFS)
gas flow
peculiar galaxy (p)
radio galaxy (RG)
Seyfert galaxy (Sy)
submillimeter galaxy (SMG)