Radio galaxy

Radio galaxies and their relatives, radio-loud quasars and blazars, are types of active galaxy that are very luminous at radio wavelengths (up to 1038 W between 10 MHz and 100 GHz). The radio emission is due to the synchrotron process. The observed structure in radio emission is determined by the interaction between twin jets and the external medium, modified by the effects of relativistic beaming. Radio-loud active galaxies are interesting not only in themselves, but also because they can be detected at large distances, making them valuable tools for observational cosmology. Recently, a good deal of work has been done on the effects of these objects on the intergalactic medium, particularly in galaxy groups and clusters.
See more at Wikipedia.org...

A galaxy which is an intense source of radio waves. It is a form of active galaxy. Radio galaxies are always elliptical galaxies. The radio emission usually comes from two huge lobes on either side of the galaxy. The lobes themselves can be millions of light years across and are often credited with being the largest single objects in the entire universe. The radio waves are produced by the synchrotron emission process. Radio galaxies are not yet fully understood.