Radio Galaxies

Strong radio sources are typically identified with giant elliptical galaxies, although some of the brightest radio sources are associated with quasars. Two types of radio galaxies have optical spectra of the sort that we identify with AGN activity; broad-line radio galaxies (BLRGs) and narrow-line radio galaxies (NLRGs) are the radio-loud analogs of type 1 and type 2 Seyfert galaxies, respectively. As a class, they have a number of differences from their radio-quiet counterparts, but in terms of basic phenomenology, they can be considered to be radio-loud Seyferts. One important difference is that they appear to occur in elliptical galaxies rather than spirals.

Adapted from B.M. Peterson An Introduction to Active Galactic Nuclei, Cambridge University Press, (1997)