active galaxy


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active galaxy

n.
A galaxy that is many times brighter than other galaxies of the same type. Active galaxies commonly emit most of their excess luminosity from a compact active galactic nucleus.
American Heritage® Dictionary of the English Language, Fifth Edition. Copyright © 2016 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

active galaxy

n
(Astronomy) a galaxy that emits usually large amounts of energy from a very compact central source, such as Seyfert galaxies, radio galaxies, and quasars. Also called: active galactic nucleus
Collins English Dictionary – Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014
References in periodicals archive ?
According to the scientists, they first saw the UFOs escaping after studying an active galaxy known as PG 1114+445 .
A quasar is the extremely bright nucleus of an active galaxy and its powerful glow is created by the incredible amounts of energy released by gas falling toward the supermassive black hole at its centre.
The author is founder of Active Galaxy Productions and community outreach coordinator for The Ohio State UniversityAEs Department of Astronomy; he appears on the Science Channel.
"In our case, we saw an active galaxy, which is a large galaxy containing a gigantic black hole at its centre," explains Kowalski.
ASTRONOMERS have discovered an object in the active galaxy Cygnus A that wasn't there before.
Following a massive recall effort, Samsung will remotely disable the remaining active Galaxy Note 7 handsets before the end of this month, according to a (http://www.koreaherald.com/view.php?ud=20170324000416) report from the Korea Herald.
Caption: An active galaxy called a blazar, illustrated here, emits a jet of high-energy particles toward Earth.
In 2013 and 2014 the international team carried out the most extensive monitoring campaign of an active galaxy ever conducted.
M64 is quite an active galaxy with many regions of star formation, which may be the result of an interaction with a companion.
The devastating collision has drastically altered the appearance of both sets of stars creating huge amounts of heat - turning NGC 6240 into what experts call an "infrared luminous" active galaxy.
The other two of VSOP's `three key sources' are NGC 4258, the best black hole candidate, and the galaxy Virgo A, another active galaxy, but further off than Centaurus A.