Astronomy and Astrophysics – Astrophysics
Scientific paper
2004-08-30
Astrophys.J. 618 (2005) 618-634
Astronomy and Astrophysics
Astrophysics
41 pages, 13 figures, to appear in the 2005 January 10 issue of the Astrophysical Journal. High resolution versions of the fig
Scientific paper
10.1086/426101
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 << 1. Thus, the disk is most likely clumpy, and we argue that it is probably forming stars. Overall, the accretion disk in NGC 3079 stands in contrast to the compact, thin, warped, differentially rotating disk in the archetypal maser galaxy NGC 4258 (abridged).
Greenhill Lincoln J.
Kondratko Paul T.
Moran James Michael
No associations
LandOfFree
Evidence for a Geometrically Thick Self-Gravitating Accretion Disk in NGC 3079 does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Evidence for a Geometrically Thick Self-Gravitating Accretion Disk in NGC 3079, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Evidence for a Geometrically Thick Self-Gravitating Accretion Disk in NGC 3079 will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-512239