Masers in AGN environments

Abstract

Galactic nuclei are well known sources of OH and H2O maser emission. It appears that intense star formation in ultra-luminous infrared galaxies drives most OH sources. In contrast, nuclear activity appears to drive most H2O sources. When H2O emission originates in accretion disk structures, constrained geometry and dynamics enable robust interpretation of spectroscopic and imaging data. The principal science includes study of AGN geometry at parsec and sub-parsec radii and measurement of geometric distances in the Hubble Flow. New high accuracy estimates of the Hubble constant, "Ho," obtained from maser distances may enable new substantively improved constraints on fundamental cosmological parameters (e.g., dark energy).

10 pages, 6 figures, to appear in proceedings of IAU Symposium 242 "Astrophysical Masers and their Environments", held in Alice Springs, March 2007

References in corpus (6)

• A new Cepheid distance to the maser-host galaxy NGC 4258 and its implications for the Hubble Constant
• Discovery of Water Maser Emission in Five AGN and a Possible Correlation Between Water Maser and Nuclear 2-10 keV Luminosities
• Sensitive VLBI Studies of the OH Megamaser Emission from IRAS 17208-0014
• Low-luminosity Extragalactic Water Masers toward M82, M51, and NGC4051
• The water megamaser in the merger system Arp299
• Probing the feeding and feedback of AGN through molecular line maps

Cited by in corpus (1)

• High accretion rates in magnetised Keplerian discs mediated by a Parker instability driven dynamo