0 Accretion and Outflow in the Circinus AGN

The first VLBI images of H2O maser emission in the Circinus Galaxy AGN show both an accretion disk and outflow 0.1 to 1 pc from the central engine. The maser traces a warped, edge-on accretion disk between radii of about 0.1 and 0.4 pc that is bound by a 1.3 × 10 6 M⊙ central mass. The rotation curve is somewhat flatter than a Keplerian rotation law and is consistent with a disk mass on the order of 10 5 M⊙. Clumpy substructure may display a kinematic signature consistent with spiral arms. Away from the disk, a second population of water masers traces broadly a bipolar, wide-angle outflow that contains (bullet-like) clumps ejected from a region centered on the central engine and < 0.1 pc in radius. Out to a radius of ∼ 0.4 pc, the warp of the accretion disk appears to channel the outflow, the orientation of which on the sky coincides with the orientation of the known kiloparsec-scale ionization cone. Beyond this radius, the flow crosses the disk and truncates it. This suggests that the current accretion event and associated disk-outflow geometry have a lifetime on the order of 10 7 years.