We discuss optical colors of galaxies observed in five bands by the Sloan Digital Sky Survey (SDSS) for ~100 deg2 of sky along the Celestial Equator. The distribution of galaxies in the g*-r^* vs. u*-g^* color-color diagram is clearly bimodal. We use both visual morphology and spectral classification of a subsample of 500 galaxies to show that the two regions correspond to elliptical and spiral galaxies as expected due to their different stellar populations. We also find that the differences in the colors of galaxies are well correlated with the differences in their radial profiles, as measured by the concentration index (the ratio of the galactic radii containing 50 galaxy light) and the likelihood ratio of the exponential and de Vaucouleurs fits to the radial profiles.
American Astronomical Society Meeting Abstracts
- Pub Date:
- December 2000