The 2dF QSO Redshift Survey- XV. Correlation Analysis of Redshift-Space Distortions

We analyse the redshift-space (z-space) distortions of QSO clustering in the 2dF QSO Redshift Survey (2QZ). To interpret the z-space correlation function, ξ(σ, π), we require an accurate model for the QSO real-space correlation function, ξ(r). Although a single power-law ξ(r) ∝ r−γ model fits the projected correlation function (wp(σ)) at small scales, it implies somewhat too shallow a slope for both wp(σ) and the z-space correlation function, ξ(s), at larger scales ( ∼> 20 h−1Mpc). Motivated by the form for ξ(r) seen in the 2dF Galaxy Redshift Survey (2dFGRS) and in standard ΛCDM predictions, we use a double power-law model for ξ(r) which gives a good fit to ξ(s) and wp(σ). The model is parametrized by a slope of γ = 1.45 for 1 < r < 10h−1Mpc and γ = 2.30 for 10 < r < 40h−1Mpc. As found for 2dFGRS, the value of β determined from the ratio of ξ(s)/ξ(r) depends sensitively on the form of ξ(r) assumed. With our double power-law form for ξ(r), we measure β(z = 1.4) = 0.32 +0.09 −0.11. Assuming the same model for ξ(r) we then analyse the z-space distortions in the 2QZ