The 2dF QSO Redshift Survey — II. Structure and evolution at high redshift

• Published in: Monthly notices of the Royal Astronomical Society 2001-08, Vol.325 (2), p.483-496
• Main Authors: Croom, Scott M., Shanks, T., Boyle, B.J., Smith, R.J., Miller, L., Loaring, N.S., Hoyle, F.
• Format: Article
• Language: English
• Subjects: cosmology: observations; galaxies: clusters: general; large-scale structure of Universe; quasars: general
• ISSN: 0035-8711; 1365-2966
• DOI: 10.1046/j.1365-8711.2001.04389.x

In this paper we present a clustering analysis of QSOs over the redshift range z=0.3–2.9. We use a sample of 10 558 QSOs taken from the preliminary data release catalogue of the 2dF QSO Redshift Survey (2QZ). The two-point redshift-space correlation function of QSOs, ξQ(s), is shown to follow a power law on scales s≃1–35 h−1 Mpc. Fitting a power law of the form ξQ(s)=(s/s0)−γ to the QSO clustering averaged over the redshift interval 0.399 per cent confidence level). A redshift-dependent bias is required to reconcile QSO clustering observations with theory. A simple biasing model, in which QSOs have cosmologically long lifetimes (or alternatively form in peaks above a constant threshold in the density field), is acceptable in an Ω0=1 cosmology, but is only marginally acceptable if Ω0=0.3 and λ0=0.7. Biasing models in which QSOs are assumed to form over a range in redshift, based on the Press–Schechter formalism, are consistent with QSO clustering evolution for a minimum halo mass of ∼1012 and ∼1013 M⊙ in an Einstein–de Sitter and cosmological constant dominated universe, respe