Environmental Dependence of Different Colors for the Apparent Magnitude-Limited Main Galaxy Sample of the SDSS DR7

Abstract

The apparent magnitude-limited Main galaxy sample of the Sloan Digital Sky Survey Data Release 7 is used to investigate the environmental dependence of u–r, u–g, g–r, r–i and i–z colors. All the five colors strongly correlate with the local environment: red galaxies tend to be located in dense regions, while blue galaxies tend to be located in low density regions. We also note that with increasing of redshift, the environmental dependence of galaxy colors becomes weaker, especially in the high redshift region (z between 0.17 and 0.20). This can be explained accepting that subsamples with high redshifts contain only luminous and red galaxies.

Keywords

• galaxies: fundamental parameters
• galaxies: statistics