Evolution of the Galaxy Luminosity Function for Redshift and Density Environment at 0.03 <z< 0.5

Using galaxy sample observed by the BATC large-field multi-color sky surveyand galaxy data of SDSS in the overlapped fields, we study the dependence ofthe restframe $r$-band galaxy luminosity function on redshift and onlarge-scale environment. The large-scale environment is defined by isodensitycontour with density contrast \delta\rho/\rho. The data set is a compositesample of 69,671 galaxies with redshifts 0.03 < z < 0.5 and r < 21.5 mag. Theredshifts are composed by three parts: 1) spectroscopic redshifts in SDSS forlocal and most luminous galaxies; 2) 20-color photometric redshifts derivedfrom BATC and SDSS; 3) 5-color photometric redshifts in SDSS. We find that thefaint-end slope \alpha steepens slightly from -1.21 at z ~ 0.06 to -1.35 at z ~0.4, which is the natural consequence of the hierarchical formation ofgalaxies. The luminosity function also differs with different environments. Thevalue of \alpha changes from -1.21 at underdense regions to -1.37 at overdenseregions and the corresponding M* brightens from -22.26 to -22.64. This suggeststhat the fraction of faint galaxies is larger in high density regions than inlow density regions.Comment: 7 pages, 9 figures, accepted by Ap