The Discovery of H 2 O Maser Emission in Seven Active Galactic Nuclei and at High Velocities in the Circinus Galaxy

We report the discovery of H2O maser emission at 1.35 cm wavelength in sevenactive galactic nuclei (at distances up to <80 Mpc) during a survey conductedat the 70-m diameter antenna of the NASA Deep Space Network near Canberra,Australia. The detection rate was (approx.) 4%. Two of the maser sources areparticularly interesting because they display satellite high-velocity emissionlines, which are a signature of emission from the accretion disks ofsupermassive black holes when seen edge on. Three of the masers are coincident,to within uncertainties of 0.''2, with continuum emission sources we observedat about (lamda)1.3 cm. We also report the discovery of new spectral featuresin the Circinus galaxy H2O maser that broaden the known velocity range ofemission therein by a factor of (approx.) 1.7. If the new spectral featuresoriginate in the Circinus accretion disk, then molecular material must surviveat radii (approx.) 3 times smaller than had been believed previously [(approx.)0.03 pc or (approx.) 2 x 105 Schwarzschild radii].Comment: 4 pages, including 2 figures. To appear in ApJ Letters Jan. 1, 2003 editio