Luminosity-environment relation in the redshift region of 0.60 ≤ z ≤ 0.75

Abstract

In this work, I construct a LRG sample with the redshift of 0.6 ≤ z ≤ 0.75 from the Sloan Digital Sky Survey Data Release 15 (SDSS DR15), which contains 184172 CMASS LRGs and 27158 eBOSS LRGs and examine the environmental dependence of the u-, g-, r-, i- and z-band luminosities in this galaxy sample. I divide this LRG sample into subsamples with a redshift binning size of Δz=0.01, and analyze the environmental dependence of all five band luminosities for these subsamples in each redshift bin. Overall, u-band luminosity is nearly independent of the local environment in all redshift bins. Though the environmental dependence of g-band luminosity is weak, a substantial luminosity-density correlation can be observed in some high redshift bins. The environmental dependence of r-, i- and z-band luminosities still is minimal in low redshift bins, like u- and g-band luminosities do. It is noteworthy that in high redshift bins, r-, i- and z-band luminosities have a strongly abnormal correlation with environments: luminous galaxies tend to reside in low density regions, while faint galaxies tend to reside in dense environments, like u-band luminosity in the apparent-magnitude limited Main galaxy sample does.