The 2dF Galaxy Redshift Survey: Cosmological Parameters and Galaxy Biasing

Abstract

The 2dF Galaxy Redshift Survey (2dFGRS) has already measured over 220,000 redshifts of nearby (z ~0.1) galaxies. It allows us to estimate fundamental cosmological parameters and to subdivide the survey into subsets according to the galaxy intrinsic properties. The large-scale structure analysis of the survey has already yielded several significant results: (i) the shape of the power spectrum of fluctuations is consistent with the Lambda - Cold Dark Matter concordance model; (ii) from joint analysis of the 2dFGRS data with the Cosmic Microwave Background anisotropies the linear-theory rms mass fluctuations is sigma_8m ~ 0.73, lower than the COBE-alone normalization and previous estimates from cluster abundance and cosmic shear; (iii) The biasing parameter of bright galaxies on scales > 10 Mpc/h is nearly unity; and (iv) on scales smaller than < 10 Mpc/h red galaxies are more strongly clustered than blue galaxies.