| Evidence for a Geometrically Thick Self-Gravitating Accretion Disk in NGC 3079 (2004) | |||||||||
Abstract | |||||||||
| We have mapped, for the first time, the full velocity extent of the water maser emission in NGC 3079. The largely north-south distribution of emission, aligned with a kpc-scale molecular disk, and the segregation of blue- and red-shifted emission on the sky are suggestive of a nearly edge-on molecular disk on pc-scales. Positions and line-of-sight velocities of blue- and red-shifted maser emission are consistent with a central mass of ~2 x 10^6 Msun enclosed within a radius of ~0.4 pc. The corresponding mean mass density of 10^6.8 Msun pc^-3 is suggestive of a central black hole, which is consistent with the detection of hard X-ray excess (20-100 keV) and an Fe Kalpha line from the nucleus. Because the rotation curve traced by the maser emission is flat, the mass of the pc-scale disk is significant with respect to the central mass. Since the velocity dispersion of the maser features does not decrease with radius and constitutes a large fraction of the orbital velocity, the disk is probably thick and flared. The rotation curve and the physical conditions necessary to support maser emission imply a Toomre Q-parameter that is . Comment: 41 pages, 13 figures, to appear in the 2005 January 10 issue of the Astrophysical Journal. High resolution versions of the figures and of the paper are available at http://cfa-www.harvard.edu/~pkondratko/publications/NGC3079/ | |||||||||
Publication details | |||||||||
| |||||||||