Pattern speeds in the Milky Way.
Abstract
A brief review is given of different methods used to determine the pattern speeds of the Galactic bar and spiral arms. The Galactic bar rotates rapidly, with corotation about halfway between the Galactic center and the Sun, and outer Lindblad resonance not far from the solar orbit, R_0. The Galactic spiral arms currently rotate with a distinctly slower pattern speed, such that corotation is just outside R_0. Both structures therefore seem dynamically decoupled.
- Publication:
-
Memorie della Societa Astronomica Italiana Supplementi
- Pub Date:
- 2011
- DOI:
- arXiv:
- arXiv:1003.2489
- Bibcode:
- 2011MSAIS..18..185G
- Keywords:
-
- Galaxy: structure;
- Galaxy: kinematics and dynamics;
- Galaxy: fundamental parameters;
- Galaxy: disk;
- Galaxy: bulge;
- Galaxies: spiral;
- Astrophysics - Galaxy Astrophysics;
- Astrophysics - Cosmology and Extragalactic Astrophysics
- E-Print:
- 4 pages, invited talk to appear in "Tumbling, twisting, and winding galaxies: Pattern speeds along the Hubble sequence", E. M. Corsini and V. P. Debattista (eds.), Memorie della Societa`Astronomica Italiana