The discovery of H2O 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 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 similar to4%. 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 lambda = 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 similar to1.7. If the new spectral features originate in the Circinus accretion disk, then molecular material must survive at radii similar to3 times smaller than had been believed previously (similar to0.03 pc or similar to2 x 10(5) Schwarzschild radii).