Radio galaxies are usually elliptical and generally emits very high amount of the radio waves.
They typically exhibit two lobes of radio frequency emission that are often approximately aligned with the jets observed in the visible spectrum and that may extend for millions of light years.
The centers of radio galaxies are active galactic nuclei, and many expel one or more jets of matter directly from the nucleus that can be observed in the visible spectrum and extend for millions of light-years.
They are predominantly luminous systems. They are more likely to have companions or be in groups or clusters than optically similar radio-quiet galaxies
ATCA image by A. Koekemoer, R. Schilizzi, G. Bicknell and R. Ekers