First Constraints on Growth Rate from Redshiftspace Ellipticity Correlations of SDSS Galaxies at 0.16 < z < 0.70
Abstract
We report the first constraints on the growth rate of the universe, f(z)σ _{8}(z), with intrinsic alignments (IAs) of galaxies. We measure the galaxy densityintrinsic ellipticity crosscorrelation and intrinsic ellipticity autocorrelation functions over 0.16 < z < 0.7 from luminous red galaxies (LRGs) and LOWZ and CMASS galaxy samples in the Sloan Digital Sky Survey (SDSS) and SDSSIII BOSS survey. We detect clear anisotropic signals of IA due to redshiftspace distortions. By combining measured IA statistics with the conventional galaxy clustering statistics, we obtain tighter constraints on the growth rate. The improvement is particularly prominent for the LRG, which is the brightest galaxy sample and known to be strongly aligned with underlying dark matter distribution; using the measurements on scales above 10 h ^{1} Mpc, we obtain $f{\sigma }_{8}={0.5196}_{0.0354}^{+0.0352}$ (68% confidence level) from the clusteringonly analysis and $f{\sigma }_{8}={0.5322}_{0.0291}^{+0.0293}$ with clustering and IA, meaning 19% improvement. The constraint is in good agreement with the prediction of general relativity, f σ _{8} = 0.4937 at z = 0.34. For LOWZ and CMASS samples, the improvement of constraints on f σ _{8} is found to be 10% and 3.5%, respectively. Our results indicate that the contribution from IA statistics for cosmological constraints can be further enhanced by carefully selecting galaxies for a shape sample.
 Publication:

The Astrophysical Journal
 Pub Date:
 March 2023
 DOI:
 10.3847/20418213/acbf48
 arXiv:
 arXiv:2301.06273
 Bibcode:
 2023ApJ...945L..30O
 Keywords:

 Largescale structure of the universe;
 Cosmology;
 Accelerating universe;
 Cosmological parameters from largescale structure;
 Redshift surveys;
 902;
 343;
 12;
 340;
 1378;
 Astrophysics  Cosmology and Nongalactic Astrophysics;
 Astrophysics  Astrophysics of Galaxies;
 General Relativity and Quantum Cosmology
 EPrint:
 9 pages, 5 figures, matches version published in ApJL