Active galactic nuclei

http://astrothesaurus.org/uat/16

alt label
AGN
AGNs
dcterms modified equal to or less than 2020-11-06T01:47:26.534Zequal to or more than 2020-11-06T01:47:26.534Z
broader
http://astrothesaurus.org/uat/17 original
narrower
16 original
http://astrothesaurus.org/uat/609 original
narrower
16 original
http://astrothesaurus.org/uat/739 original
narrower
16 original
definition A central region of an active galaxy, which is a light-year or less in diameter and has an abnormally high luminosity. The nucleus emits high energy radiation (gamma rays, X-rays, ultraviolet) and shows variability over various time-scales, sometimes very short (hours to weeks). Emission line spectra reveal high velocity motions up to 10^4 km s^-1. AGNs are divided into two main types. Type I refers to an AGN whose nucleus is visible (the spectra has both narrow and broad emission lines), while in type II AGN, the broad line region (BLR) is obscured and the lines are very narrow. This may be due either to the viewing angle or some intrinsic difference in structure.
narrower
http://astrothesaurus.org/uat/1319 original
broader
16 original
http://astrothesaurus.org/uat/1341 original
broader
16 original
http://astrothesaurus.org/uat/1344 original
broader
16 original
http://astrothesaurus.org/uat/1347 original
broader
16 original
http://astrothesaurus.org/uat/1348 original
broader
16 original
http://astrothesaurus.org/uat/1352 original
broader
16 original
http://astrothesaurus.org/uat/1388 original
broader
16 original
164 original
broader
16 original
http://astrothesaurus.org/uat/2033 original
broader
16 original
http://astrothesaurus.org/uat/2034 original
broader
16 original
http://astrothesaurus.org/uat/2035 original
broader
16 original
http://astrothesaurus.org/uat/2134 original
broader
16 original
type
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Concept original
contributor AAS_Frey.Katie_Admin original