active galaxy


active galaxysearch for term

A "hyperactive" galaxy that emits more energy than the sum of the individual stars within it. These galaxies emit energy at wavelengths across the electromagnetic spectrum, from radio to X-ray, and they have powerful, concentrated, non-thermal energy sources at their cores. Some are also unusually bright at radio, infrared or X-ray wavelengths compared to the Milky Way. Three types of active galaxies are Seyfert Galaxies, quasars, and blazars. Many active galaxies are also radio galaxies.