Baryon acoustic oscillations from the SDSS DR10 galaxies angular correlation function

Abstract

The 2-point angular correlation function $w(\ensuremath{\theta})$ (2PACF), where $\ensuremath{\theta}$ is the angular separation between pairs of galaxies, provides the transversal baryon acoustic oscillation (BAO) signal almost model independently. In this paper we use 409 337 luminous red galaxies in the redshift range $z=[0.440,0.555]$ obtained from the tenth data release of the Sloan Digital Sky Survey (SDSS DR10) to estimate ${\ensuremath{\theta}}_{\mathrm{BAO}}(z)$ from the 2PACF at six redshift shells. Since noise and systematics can hide the BAO signature in the $w\text{\ensuremath{-}}\ensuremath{\theta}$ plane, we also discuss some criteria to localize the acoustic bump. We identify two sources of model dependence in the analysis, namely, the value of the acoustic scale from cosmic microwave background (CMB) measurements and the correction in the ${\ensuremath{\theta}}_{\mathrm{BAO}}(z)$ position due to projection effects. Constraints on the dark energy equation-of-state parameter $\mathrm{w}(z)$ from the ${\ensuremath{\theta}}_{\mathrm{BAO}}(z)$ diagram are derived, as well as from a joint analysis with current CMB measurements. We find that the standard $\mathrm{\ensuremath{\Lambda}}\mathrm{CDM}$ model as well as some of its extensions are in good agreement with these ${\ensuremath{\theta}}_{\mathrm{BAO}}(z)$ measurements.