Local Bar Properties as a Function of Wavelength
Abstract
Stellar bars play a central role in the evolution of galaxies. They are present in roughly 2/3 of all nearby galaxies and the large-scale streaming motions they induce in the gas can dramatically change the host galaxy itself.  Simulations have shown that a galaxy disk will naturally form a bar in a couple of Gyrs unless it is dynamically hot or its potential is dominated by dark matter. For cosmological studies, the redshift evolution of the bar fraction is thus an important signpost on the growth and dynamic maturity of galaxies. Because high-redshift photometric studies are subject to the progressive shifting of the photometric band to bluer rest-frame wavebands, it is necessary to gauge how bar properties (and thus, the ability to identify their presence at high redshift) vary with wavelength to reliably characterize this evolution. We investigate bar properties in 20 large nearby galaxies from the Spitzer Survey of Stellar Structure in Galaxies (S4G). We characterize bar length and ellipticity from optical (B-, R-bands from SINGS) to near-IR (J-H-Ks from 2MASS) and mid-IR (IRAC-3.6 microns) wavebands.
- Publication:
-
American Astronomical Society Meeting Abstracts #215
- Pub Date:
- January 2010
- Bibcode:
- 2010AAS...21538102M