Astrophysics (Index)About

radio galaxy

(a galaxy emitting a lot of radio)

A radio galaxy (RG) is a galaxy emitting a lot of radio electromagnetic radiation (i.e., radio-loud; The phrase radio-quiet is sometimes used to distinguish radio-loud objects from others in discussion). They have been found with as much as 1039 watts of power in the radio spectrum. Distant radio galaxies are useful as they are relatively easily observed. Some emit most of their radio emission from regions away from the center (often even beyond the visible portion of the galaxy) which are termed lobes. The spectral energy distribution and polarization often suggests synchrotron radiation as the source. An SFRG (star forming radio galaxy) has rest-frame ultraviolet spectral features consistent with a starburst galaxy. The term GRG (giant radio galaxy), naturally is used to indicate a large one, 2 Mpc being a commonly-used threshold. A radio galaxy is generally an active galaxy. Quasars and blazars with a similar radio spectrum are called radio-loud quasars and radio-loud blazars and are assumed to be more distant radio-loud radio galaxies.

(galaxy type,radio)
Further reading:

Referenced by pages:
bipolar outflow
cosmic gamma ray background (CGB)
Cygnus A (3C 405)
Fanaroff-Riley classification
Green Bank 6-cm Radio Source Catalog (GB6)
Meier paradox
Parkes Catalog (PKS)
Parkes-MIT-NRAO Surveys (PMN)
quasar (QSO)
radio source counts
redshift-angular size relation
RASS/Green Bank Catalog (RGB)
Radio Galaxy Zoo (RGZ)
radio source (RS)
3C 295
3C 303
3C 48