active galactic nucleus


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active galactic nucleus

n.
A galactic nucleus that emits more radiation than can be accounted for solely by light from the stars it contains.
References in periodicals archive ?
This result is crucial in order to understand how an active galactic nucleus influences the surrounding galaxy," says Schawinski, who led the study.
Each such area is known as an active galactic nucleus (called AGN).
They strengthen the case for an active galactic nucleus in the Milky Way's relatively recent past," he said.