Tuesday, August 6, 2013

1308.0630 (Fernando de Simoni et al.)

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

Fernando de Simoni, Flavia Sobreira, Aurelio Carnero, Ashley J. Ross, Hugo O. Camacho, Rogerio Rosenfeld, Marcos Lima, Luiz A. N. da Costa, Marcio A. G. Maia
We analyze the large-scale angular correlation function (ACF) of the CMASS Luminous Galaxies (LGs), a photometric-redshift catalog based on the 8th data release (DR8) of the SDSS-III. This catalog contains over 600,000 LGs in the range $0.45 \leq z \leq 0.65$, which was split into four redshift shells of constant width. First, we estimate the constraints on the redshift space distortion (RSD) parameters $b\sigma_8$ and $f\sigma_8$, where $b$ is the galaxy bias, $f$ the growth rate and $\sigma_8$ 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 $f\sigma_8 = 0.69 \pm 0.21$, which agrees at the $1.5\sigma$ level with BOSS 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 BAO peak position for the four redshift shells, and combined with the sound horizon scale from WMAP7 to produce the constraints $\Omega_{m}=0.249 \pm 0.031$ and $w=-0.885 \pm 0.145$. In the second analysis, we used the ACF full shape information to constrain cosmology using real data for the first time, finding $\Omega_{m} = 0.280 \pm 0.022$ and $f_b = \Omega_b/\Omega_m = 0.211 \pm 0.026$. 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.
View original: http://arxiv.org/abs/1308.0630

No comments:

Post a Comment