An active galactic nucleus (AGN) is a compact region at the center of a galaxy that emits a significant amount of energy across the electromagnetic spectrum...

"active" if they contain an active galactic nucleus (AGN). A significant portion of the galaxy's total energy output is emitted by the active nucleus instead...

structure. These energetic radio lobes are powered by jets from its active galactic nucleus. They have luminosities up to 1039 W at radio wavelengths between...

the Milky Way's 1 M☉ per annum of star production); the central active galactic nucleus attested to not have been producing sufficient energy to ionize...

about 40 million light-years (12.5 megaparsecs). NGC 5643 has an active galactic nucleus and is a type II Seyfert galaxy. The galaxy was first discovered...

Nucleus may also refer to: Active galactic nucleus in astronomy Comet nucleus, the solid, central part of a comet Cell nucleus, a central organelle of a...

A quasar (/ˈkweɪzɑːr/ KWAY-zar) is an extremely luminous active galactic nucleus (AGN). It is sometimes known as a quasi-stellar object, abbreviated QSO...

general Active galactic nucleus Galactic bulge Galactic disc Galactic habitable zone Galactic halo Dark matter halo Galactic corona Galactic magnetic...

region. The coexistence of a circumnuclear starburst ring and an active galactic nucleus have turned NGC 7469 into a key target for studying their relation...

luminous quasars known. As a quasar, TON 618 is believed to be the active galactic nucleus at the center of a galaxy, the engine of which is a supermassive...