AGN and Megamasers

Abstract

Luminous extragalactic masers are traditionally referred to as the `megamasers'. Those produced by water molecules are associated with accretion disks, radio jets, or outflows in the nuclear regions of active galactic nuclei (AGN). The majority of OH maser sources are instead driven by intense star formation in ultra-luminous infrared galaxies, although in a few cases the OH maser emission traces rotating (toroidal or disk) structures around the nuclear engines of AGN. Thus, detailed maser studies provide a fundamental contribution to our knowledge of the main nuclear components of AGN, constitute unique tools to measure geometric distances of host galaxies, and have a great impact on probing the, so far, paradigmatic Unified Model of AGN.

11 pages, 3 figures, invited review to appear in Proc. IAU 287 "Cosmic Masers: from OH to H_0", R.S. Booth, E.M.L. Humphreys and W.H.T. Vlemmings, eds

References in corpus (8)

• On the Unification of Active Galactic Nuclei
• Prevalence of High X-ray Obscuring Columns among AGN that Host H${}_2$O Masers
• A gravitationally lensed water maser in the early Universe
• Discovery of Water Maser Emission in Five AGN and a Possible Correlation Between Water Maser and Nuclear 2-10 keV Luminosities
• Positional Coincidence of H2O Maser and a Plasma Obscuring Torus in Radio Galaxy NGC 1052
• Optical Properties of Host Galaxies of Extragalactic Nuclear Water Masers
• The water megamaser in the merger system Arp299
• A search for water maser emission in nearby low-luminosity QSO host galaxies

Cited by in corpus (8)

• NuSTAR observations of water megamaser AGN
• How to constrain mass and spin of supermassive black holes through their disk emission
• Diagnostics of a Nuclear Starburst: Water and Methanol Masers
• Water masers in Compton-thick AGN II. The high detection rate and EVN observations of IRAS 15480-0344
• Hubble distancing: Focusing on distance measurements in cosmology
• Water megamaser emission in hard X-ray selected AGN
• Water masers in Compton-thick AGN I. Detailed study of the new water megamaser in IRAS15480-0344
• H${}_2$O Maser Pumping: The Effect of Quasi-Resonance Energy Transfer in Collisions between H${}_2$ and H${}_2$O Molecules