The Black Hole Mass and Extreme Orbital Structure in NGC1399
Abstract
The largest galaxies, and in particular central galaxies in clusters, offer unique insight into understanding the mechanism for the growth of nuclear black holes. We present Hubble Space Telescope kinematics for NGC1399, the central galaxy in Fornax. We find the best-fit model contains a black hole of 5.1 +-0.7 x 10^8 Msun (at a distance of 21.1 Mpc), a factor of over 2 below the correlation of black hole mass and velocity dispersion. We also find a dramatic signature for central tangential anisotropy. The velocity profiles on adjacent sides 0.5" away from the nucleus show strong bimodality, and the central spectrum shows a large drop in the dispersion. Both of these observations point to an orbital distribution that is tangentially biased. The best-fit orbital model suggests a ratio of the tangential to radial internal velocity dispersions of three. This ratio is the largest seen in any galaxy to date and will provide an important measure for the mode by which the central black hole has grown.
Keywords
Cite
@article{arxiv.0709.0585,
title = {The Black Hole Mass and Extreme Orbital Structure in NGC1399},
author = {Karl Gebhardt and Tod R. Lauer and Jason Pinkney and Ralf Bender and Douglas Richstone and Monique Aller and Gary Bower and Alan Dressler and Sandra Faber and Alexei Filippenko and Richard Green and Luis Ho and John Kormendy and Christos Siopis and Scott Tremaine},
journal= {arXiv preprint arXiv:0709.0585},
year = {2009}
}
Comments
9 pages, accepted for publication in the Astrophysical Journal