{[ promptMessage ]}

Bookmark it

{[ promptMessage ]}

Introducing Active Galactic Nuclei

Introducing Active Galactic Nuclei - Recognition that...

Info iconThis preview shows page 1. Sign up to view the full content.

View Full Document Right Arrow Icon
Introducing Active Galactic Nuclei Active galactic nuclei (AGN) may be defined loosely as the central regions of galaxies which show substantial energy release beyond what can be attributed to normal processes from stars, ISM, and their interactions. This includes Seyfert galaxies, radio galaxies, quasars, QSOs, BL Lac objects, and possibly the common LINERs in ordinary galaxies. They may also encompass N-galaxies and X-ray bright galaxies. These classifications are not necessarily mutually exclusive, being based on disparate criteria.
Background image of page 1
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: Recognition that galactic nuclei can be sites of very energetic and compact phenomena largely began with the identification of strong radio sources with galaxies - sometimes peculiar in form, frequently with the radio emission arising in the form of a pair of sources symmetrically located about the galaxy ("double-lobed radio source"). Early interferometer positions for the lobes are superimposed in a photograph of Cygnus A in Fig. 15 of Matthews, Morgan, and Schmidt 1964 ApJ 140, 35 (courtesy of the AAS):...
View Full Document

{[ snackBarMessage ]}