Constraining β(z) and Ω0mfrom redshift-space distortions inz∼ 3 galaxy surveys

Abstract

We use a sample of 813 Lyman-break galaxies (LBGs) with 2.6 < z < 3.4 to perform a detailed analysis of the redshift-space (z-space) distortions in their clustering pattern, and from that derive confidence levels in the [� 0, β(z = 3)] plane. We model the z-space distortions in the shape of the correlation function measured in orthogonal directions, ξ (σ , π ). This modelling requires an accurate description of the real-space correlation function to be given as an input. From the projection of ξ (σ , π )i nthe angular direction, wp (σ ), we derive the best-fitting amplitude and slope for the LBG real-space correlation function: r 0 = 4.48 +0.17 −0.18 h −1 Mpc and γ = 1.76 +0.08 −0.09 [ξ (r ) = (r/r 0) −γ ]. A comparison between the shape of ξ (s) and wp (σ ) suggests that ξ (r )d eviates from a simple power-law model, with a break at ∼9 h −1 Mpc. This model is consistent with the observed projected correlation function. However, due to the limited size of the fields used, the w p(σ ) results are limited to σ 10 h −1 Mpc. Assuming this doublepower-law model, and by analysing the shape distortions in ξ (σ , π ), we find the following constraints: β(z = 3) = 0.15 +0.20