active galaxy

noun

1. Also called: active galactic nucleus. a galaxy that emits usually large amounts of energy from a very compact central source, such as Seyfert galaxies, radio galaxies, and quasars

active galaxy

1. A galaxy emitting unusually high quantities of radiation from an active galactic nucleus at its center. Some active galaxies emit more energy in radio wavelengths than they do visible light. Seyfert galaxies are examples of active galaxies.

2. See more at galactic nucleus

Example Sentences

Blazars are a type of active galaxy powered by supermassive black holes that shoot out powerful, narrow jets of particles and radiation at nearly the speed of light.

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OJ 287 is classified as a blazar, a type of active galaxy known for its intense energy and brightness.

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NGC 4945 is an active galaxy about 13 million light-years away in the southern constellation Centaurus.

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An active galaxy has an unusually bright and variable center powered by a supermassive black hole that heats a surrounding disk of gas and dust through gravitational and frictional forces.

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The detection of neutrinos ostensibly coming from this active galaxy is a big deal.

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