active galactic nuclei. The centers of active galaxies that are emitting large amounts of excess energy.
Active Galactic Nuclei. A galaxy with an unusually bright central region thought to contain a supermassive black hole actively pulling in tremendous amounts of matter from a swirling disk of gas, stars, and dust.
Active galactic nuclei. A class of galaxies that expell massive amounts of energy from their centers, far more than ordinary galaxies. Many astronomers believe supermassive black holes may lie at the center of these galaxies and power their explosive energy output.
active galactic nuclei. the tiny central engine (likely a supermassive black hole) that drives the active galaxy phenomenon
Active Galaxy Nucleus. The central energy source of an active galaxy