Astronomy and Astrophysics – Astrophysics
Scientific paper
2004-06-03
Mon.Not.Roy.Astron.Soc. 353 (2004) 1
Astronomy and Astrophysics
Astrophysics
15 pages, 9 figures. MNRAS, in press. PDF version with full-resolution figures available at http://www.phy.ohioiu.edu/~tss/p
Scientific paper
10.1111/j.1365-2966.2004.08062.x
Supermassive black holes in the centres of giant elliptical galaxies are thought to induce chaos and eliminate triaxiality in their hosts. We address whether this process operates in real systems, by modeling the stellar kinematics of the old elliptical NGC 4365. This galaxy has a mean stellar population age > 12 Gyr and is known for its kinematically decoupled core and skew rotation at larger radii. We fit the two-dimensional mean velocity field obtained by the SAURON integral-field spectrograph, and the isophotal ellipticity and position-angle profiles, using the velocity field fitting approach. We find NGC 4365 to be strongly triaxial (triaxiality parameter T approximately 0.45) and somewhat flatter than it appears. Axisymmetry or near axisymmetry (T < 0.1) is ruled out at > 95% confidence. In the most probable orientation the long axis points roughly toward the observer, extending to the southwest in projection. Strong triaxiality has persisted for hundreds of dynamical times, ruling out black holes above 3 x 10^9 solar masses. The M-sigma relation predicts 4 x 10^8 solar masses, which would not preclude long-lived triaxiality and is consistent with the observations. NGC 4365 lends support to a picture in which supermassive black holes, while omnipresent in luminous giant elliptical galaxies, are not massive enough to alter their global structure through chaos.
Bacon Roland
Emsellem Eric
Peletier Reynier F.
Statler Thomas S.
No associations
LandOfFree
Long-Lived Triaxiality in the Dynamically Old Elliptical Galaxy NGC 4365: A Limit on Chaos and Black Hole Mass 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 Long-Lived Triaxiality in the Dynamically Old Elliptical Galaxy NGC 4365: A Limit on Chaos and Black Hole Mass, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Long-Lived Triaxiality in the Dynamically Old Elliptical Galaxy NGC 4365: A Limit on Chaos and Black Hole Mass will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-58937