Large-scale analysis of the SDSS-III DR8 photometric luminous galaxies angular correlation function

Abstract

We analyse the large-scale angular correlation function (ACF) of the CMASS luminous galaxies (LGs), a photometric-redshift catalogue based on the Data Release 8 (DR8) of the Sloan Digital Sky Survey-III. This catalogue contains over 600 000 LGs in the range 0.45 ≤ z ≤ 0.65, which was split into four redshift shells of constant width. First, we estimate the constraints on the redshift-space distortion (RSD) parameters bσ8 and fσ8, where b is the galaxy bias, f the growth rate and σ8 is the normalization of the perturbations, finding that they vary appreciably among different redshift shells, in agreement with previous results using DR7 data. When assuming constant RSD parameters over the survey redshift range, we obtain fσ8 = 0.69 ± 0.21, which agrees at the 1.5σ level with Baryon Oscillation Spectroscopic Survey DR9 spectroscopic results. Next, we performed two cosmological analyses, where relevant parameters not fitted were kept fixed at their fiducial values. In the first analysis, we extracted the baryon acoustic oscillation peak position for the four redshift shells, and combined with the sound horizon scale from 7-year Wilkinson Microwave Anisotropy Probe (WMAP7) to produce the constraints ωm = 0.249 ± 0.031 and w = -0.885 ± 0.145. In the second analysis, we used the ACF full shape information to constrain cosmology using real data for the first time, findingωm = 0.280 ± 0.022 and fb = ωb/ωm = 0.211 ± 0.026. These results are in good agreement with WMAP7 findings, showing that the ACF can be efficiently applied to constrain cosmology in future photometric galaxy surveys. © 2013 The Authors. Published by Oxford University Press on behalf of the Royal Astronomical Society.