The Clustering of Galaxies in the SDSS-III Baryon Oscillation Spectroscopic Survey: Luminosity and Color Dependence and Redshift Evolution

We measure the luminosity and color dependence and the redshiftevolution of galaxy clustering in the Sloan Digital Sky Survey-IIIBaryon Oscillation Spectroscopic Survey Ninth Data Release. We focus onthe projected two-point correlation function (2PCF) of subsets of itsCMASS sample, which includes about 260,000 galaxies over ~3300deg² in the redshift range 0.43 z 0.7. To minimizethe selection effect on galaxy clustering, we construct well-definedluminosity and color subsamples by carefully accounting for the CMASSgalaxy selection cuts. The 2PCF of the whole CMASS sample, ifapproximated by a power-law, has a correlation length of r ₀= 7.93 ± 0.06 h ^-1 Mpc and an index of γ =1.85 ± 0.01. Clear dependences on galaxy luminosity and color arefound for the projected 2PCF in all redshift bins, with more luminousand redder galaxies generally exhibiting stronger clustering and steeper2PCF. The color dependence is also clearly seen for galaxies within thered sequence, consistent with the behavior of SDSS-II main samplegalaxies at lower redshifts. At a given luminosity (k + e corrected), nosignificant evolution of the projected 2PCFs with redshift is detectedfor red sequence galaxies. We also construct galaxy samples of fixednumber density at different redshifts, using redshift-dependentmagnitude thresholds. The clustering of these galaxies in the CMASSredshift range is found to be consistent with that predicted by passiveevolution. Our measurements of the luminosity and color dependence andredshift evolution of galaxy clustering will allow for detailed modelingof the relation between galaxies and dark matter halos and newconstraints on galaxy formation and evolution.