Direct Confirmation of Two Pattern Speeds in the Double-barred Galaxy NGC 2950
Abstract
We present the surface photometry and stellar kinematics of NGC 2950, which is a nearby and undisturbed SB0 galaxy hosting two nested stellar bars. We use the Tremaine-Weinberg method to measure the pattern speed of the primary bar. This also permits us to establish directly and for the first time that the two nested bars are rotating with different pattern speeds and, in particular, that the rotation frequency of the secondary bar is higher than that of the primary one.
Based on observations made with the UK Jacobus Kapteyn Telescope and the Italian Telescopio Nazionale Galileo operated at the Spanish Observatorio del Roque de los Muchachos of the Instituto de Astrofísica de Canarias by the Isaac Newton Group and the Istituto Nazionale di Astrofisica, respectively.- Publication:
-
The Astrophysical Journal
- Pub Date:
- December 2003
- DOI:
- 10.1086/381080
- arXiv:
- arXiv:astro-ph/0310879
- Bibcode:
- 2003ApJ...599L..29C
- Keywords:
-
- Galaxies: Elliptical and Lenticular;
- cD;
- Galaxies: Individual: NGC Number: NGC 2950;
- Galaxies: Kinematics and Dynamics;
- Galaxies: Photometry;
- Galaxies: Structure;
- Astrophysics
- E-Print:
- 12 pages, 4 figures. To appear in ApJ Letters