QSO clustering and the AAT 2dF redshift survey

The study of QSO clustering from large homogeneous surveys is likely to provide unique information on the nature of large-scale structure (LSS) in the Universe. Even with relatively modest aperture telescopes, QSOs are readily detectable from the present cosmic epoch to a time when the Universe was less than 25% of its present age. This approximately eight billion year time interval provides a unique baseline over which to study the evolution of structure in the Universe with cosmic time. QSO clustering also yields a direct measure of clustering on comoving scales ≫ 100 h−1Mpc†, providing key information (see figure 1) on LSS at scales between those provided by the COBE results (> 1000 h−1Mpc, Bennett et al. 1994) and galaxy redshift surveys (< 100 h−1Mpc, Colless et al., this volume) To date, QSO clustering has remained largely unexploited for LSS studies. This has largely been due to the lack of appropriate QSO catalogues. Although over 10000 QSOs with measured redshifts are now known (Véron & Véron-Cetty 1997, see figure 2) less than 20% of these QSOs form part of homogeneous catalogues suitable for detailed clustering analysis. The goal of the 2dF QSO redshift survey, currently underway at the Anglo-Australian Telescope (AAT), is to provide a new homogeneous catalogue of almost 30000 QSOs with which to carry out such an analysis. The survey is almost two orders of magnitude larger than the previous largest homogeneous survey to this depth (Boyle et al. 1990). In § 2 we review the existing results on QSO clustering and we describe the creation of the 2dF QSO redshift survey input catalogue in § 3. We report on the initial results from the survey in § 4 and discuss the future prospects for this and other QSO surveys in § 5.