2003ApJ...582L..11G

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 ∼2x10⁵ Schwarzschild radii).