Galactic Structure from the Spacelab Infrared Telescope. III. A Dynamical Model for the Milky Way Bulge
Abstract
The Milky Way bulge is modeled as an oblate isotropic rotator with constant M/L ratio. A model with M/L2.2 micron = 1 successfully reproduces a variety of stellar velocity dispersion measurements for R between 2 and 1200 pc. An observed increase in the stellar velocity dispersion inside 2 pc requires either that there be an additional central mass of order 3 x 10 exp 6 solar mass or that the stellar motions become anisotropic there. The model has insufficient mass to reproduce the observed peak in the H I and CO rotation curve of 250 km/s at 300 pc; it is argued that the peak arises from noncircular gas motions and does not reflect the true mass of the bulge.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- March 1992
- DOI:
- 10.1086/171070
- Bibcode:
- 1992ApJ...387..181K
- Keywords:
-
- Astronomical Models;
- Galactic Bulge;
- Galactic Structure;
- Infrared Telescopes;
- Milky Way Galaxy;
- Spacelab Payloads;
- Black Holes (Astronomy);
- Body Kinematics;
- Dark Matter;
- Mass To Light Ratios;
- Astrophysics;
- GALAXY: KINEMATICS AND DYNAMICS