Bar instability and rotation curves
Abstract
The evolution of bar unstable stellar discs is investigated using computer models. It was found that bar formation is characterized by two developmental stages: (1) bar-forming instability, and (2) a second phase during which the bar is allowed to grow further through transfer of angular momentum to stars in the outer parts of the disc, provided that a suitable cool population of stars is available to accept the angular momentum. The initial bars rotate fast enough to avoid inner Lindblad resonances with the pattern speed declining after the formation. At all stages the bars end in the neighborhood of co-rotation. Additionally, the stream flow of stars in the bar was found to be well organized, but highly non-circular. The apparent rotation curve, defined by the stream velocity of the stars, measured along the bar, was found to peak at or just outside the end of the bar, which is in tentative agreement with observations of barred galaxies.
- Publication:
-
Astronomy and Astrophysics
- Pub Date:
- June 1981
- Bibcode:
- 1981A&A....99..362S
- Keywords:
-
- Barred Galaxies;
- Computerized Simulation;
- Disk Galaxies;
- Galactic Evolution;
- Galactic Rotation;
- Rotary Stability;
- Angular Momentum;
- Astronomical Models;
- Curves (Geometry);
- Dynamic Stability;
- Star Distribution;
- Stellar Motions;
- Astrophysics