Rotation of the bulge components of barred galaxies.
Abstract
Stellar rotation and velocity-dispersion measurements are presented for the bulge components of the SB0 galaxies NGC 1023, 2859, 2950, 4340, 4371, and 7743. All of the SB bulges are found to rotate at least as rapidly as oblate-spheroid dynamical models which are flattened by rotation. Measured velocity anisotropies are found to be consistent with the conclusion that triaxial bulges are dynamically like bars and unlike elliptical galaxies, which are also believed to be triaxial, but rotate slowly. Altogether the kinematic observations imply that triaxial bulges are more disk-like than SA bulges. They appear to have been formed with more dissipation than ordinary bulges. These results are consistent with the hypothesis that part of the bulge in many SB galaxies consists of disk material which has been transported to the center by the bar. The resulting star formation may produce a very centrally concentrated light distribution which resembles a bulge but which has disk-like dynamics.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- June 1982
- DOI:
- 10.1086/159964
- Bibcode:
- 1982ApJ...257...75K
- Keywords:
-
- Barred Galaxies;
- Galactic Bulge;
- Galactic Structure;
- Star Distribution;
- Stellar Rotation;
- Velocity Distribution;
- Astronomical Photometry;
- Dynamic Models;
- Radial Velocity;
- Stellar Evolution;
- Astrophysics