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Variability of Water Megamasers in AGN

Published online by Cambridge University Press:  05 March 2013

Philip Maloney*
Affiliation:
CASA, University of Colorado, Boulder CO 80301; [email protected]
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Abstract

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Powerful water masers have been detected in 23 active galactic nuclei (AGN) to date. Most of the sources that have been monitored show evidence for variability, which may be either intrinsic (response of the masers to a time-varying pump or background source) or extrinsic (the effects of scintillation in the interstellar medium of the Galaxy). I briefly review the examples in which these mechanisms may be operating (interstellar scintillation in the Circinus galaxy, a time-varying background source in Mrk 348, and a time-varying AGN luminosity in NGC 1068).

Type
Research Article
Copyright
Copyright © Astronomical Society of Australia 2002

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