Kinematic Modeling of the Galaxy. II. Two Samples of High Proper-Motion Stars
Abstract
The paper analyzes two independent surveys, due to Fouts and Sandage and to Carney and Latham, of high proper motion stars with photoelectric photometry and line-of-sight velocity information. A purely kinematic study of both samples indicates that a two-component classical (disk + spheroid) model of the Galaxy is inadequate to represent the kinematics of stars in the solar neighborhood. A component with intermediate kinematic properties (old disk) is required. An asymmetric drift of 50 + or - 15 km/s and principal velocity dispersions of (66, 37, 38) + or - 10 km/s are determined, in good agreement with the results of the metallicity-based analysis of Sandage and Fouts and of Carney and collaborators. The density of this component is poorly constrained, and is 10 percent + or - 5 percent of the local disk density for the same color range; the scale height is less than 1 kpc.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- July 1990
- DOI:
- 10.1086/168933
- Bibcode:
- 1990ApJ...357..435C
- Keywords:
-
- Astronomical Models;
- Electrophotometry;
- Galactic Structure;
- Milky Way Galaxy;
- Stellar Motions;
- Astronomical Catalogs;
- Kinematics;
- Line Of Sight;
- Solar Neighborhood;
- Velocity Distribution;
- Astrophysics;
- GALAXIES: THE GALAXY;
- GALAXIES: STELLAR CONTENT;
- STARS: HIGH-VELOCITY;
- STARS: STELLAR DYNAMICS