Statistical and systematic errors in redshift-space distortion measurements from large surveys

• Published in: arXiv.org 2013-01
• Main Authors: Bianchi, Davide, Guzzo, Luigi, Branchini, Enzo, Majerotto, Elisabetta, de la Torre, Sylvain, Marulli, Federico, Moscardini, Lauro, Angulo, Raul E
• Format: Article
• Language: English
• Subjects: Computer simulation; Dependence; Galactic halos; Galaxies; Parameters; Red shift; Scaling formulae; Systematic errors
• ISSN: 2331-8422
• DOI: 10.48550/arxiv.1203.1545

We investigate the impact of statistical and systematic errors on measurements of linear redshift-space distortions (RSD) in future cosmological surveys, analyzing large catalogues of dark-matter halos from the BASICC simulation. These allow us to estimate the dependence of errors on typical survey properties, as volume, galaxy density and mass (i.e. bias factor) of the adopted tracer. We find that measures of the specific growth rate \beta=f/b using the Hamilton/Kaiser harmonic expansion of the redshift-space correlation function \xi(r_p,\pi) on scales larger than 3/h Mpc are typically under-estimated by up to 10% for galaxy sized halos. This is significantly larger than the corresponding statistical errors, which amount to a few percent, indicating the importance of non-linear improvements to the Kaiser model to obtain accurate measurements of the growth rate. We compare the statistical errors to predictions obtained with the Fisher information matrix, based on the usual FKP prescription for the errors on the power spectrum. We show that this produces parameter errors fairly similar to the standard deviations from the halo catalogues, but only if applied to strictly linear scales in Fourier space (k