We report the discovery of H2O maser emission at 1.35 cm wavelength in seven active galactic nuclei (at distances of up to 80 Mpc) during a survey conducted at the 70 m diameter antenna of the NASA Deep Space Network near Canberra, Australia. The detection rate was ∼4%. Two of the maser sources are particularly interesting because they display satellite high-velocity emission lines, which are a signature of emission from the accretion disks of supermassive black holes when seen edge-on. Three of the masers are coincident, to within uncertainties of 0″.2, with continuum emission sources that we observed at about λ = 1.3 cm. We also report the discovery of new spectral features in the Circinus galaxy H2O maser that broaden the known velocity range of emission therein by a factor of ∼1.7. If the new spectral features originate in the Circinus accretion disk, then molecular material must survive at radii ∼3 times smaller than had been believed previously (∼0.03 pc or ∼2 × 105 Schwarzschild radii).

Item Type:	Refereed Article
Research Division:	Physical Sciences
Research Group:	Astronomical sciences
Research Field:	Galactic astronomy
Objective Division:	Expanding Knowledge
Objective Group:	Expanding knowledge
Objective Field:	Expanding knowledge in the physical sciences
UTAS Author:	Lovell, JEJ (Dr Jim Lovell)
ID Code:	46649
Year Published:	2003
Web of Science® Times Cited:	81
Deposited By:	Physics
Deposited On:	2007-08-28
Last Modified:	2011-11-29
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