Astronomy and Astrophysics – Astrophysics
Scientific paper
2008-04-07
Astronomy and Astrophysics
Astrophysics
14 pages, 12 figures, accepted and to appear in "Frontiers of Astrophysics - A Celebration of NRAO's 50th Anniversary," ASP Co
Scientific paper
In this talk I will summarize some of the work that the CfA group has done to study the structure of the water masers in the accretion disk of NGC 4258. A series of 18 epochs of VLBA data taken from 1997.3 to 2000.8 were used for this study. The vertical distribution of maser features in the systemic group was found to have a Gaussian distribution, as expected for hydrostatic equilibrium, with a $\sigma$-width of 5.1 $\mu$as. If the disk is in hydrostatic equilibrium, its temperature is about 600K. The systemic features exhibit a small, but persistent, gradient in acceleration versus impact parameter. This characteristic may indicate the presence of a spiral density wave rotating at sub-Keplerian speed. A more precise understanding of the dynamical properties of the disk is expected to lead to a more refined estimate of the distance to the galaxy.
No associations
LandOfFree
The Black Hole Accretion Disk in NGC 4258: One of Nature's Most Beautiful Dynamical Systems 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 The Black Hole Accretion Disk in NGC 4258: One of Nature's Most Beautiful Dynamical Systems, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and The Black Hole Accretion Disk in NGC 4258: One of Nature's Most Beautiful Dynamical Systems will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-729945