Title:

Large scale structure in the Durham/UKST Galaxy Redshift Survey

The initial results from the Durham/UKST Galaxy Redshift Survey are presented here. Using this redshift survey the luminosity, clustering and dynamical properties of galaxies in the Universe are investigated. The 3D distribution of galaxies in the Durham/UKST survey appears "cellular” on 50100h(^1) Mpc scales (where h is Hubble's constant in units of 100 kms(^1) Mpc(^1)) and is clearly more complex than a simple 1D periodic pattern. The optical galaxy luminosity function of the Durham/UKST survey is estimated and can be fit by a Schechter function. Comparison with other determinations of the luminosity function shows good agreement, favouring a flat faint end slope to M(_b J) ~ 14.The redshift space 2point correlation function clustering statistic is estimated from the Durham/UKST survey. Comparison with previous estimates from other redshift surveys again shows good agreement and the Durham/UKST survey gives a detection of large scale power above and beyond that of the standard cold dark matter cosmological model on 1040h(^1)Mpc scales. The projected correlation function is also estimated from the Durham/UKST survey and is compared with models for the real space 2point correlation function. To estimate this real space correlation function directly, a new application of the RichardsonLucy inversion technique is developed, tested and then applied to the Durham/UKST survey. The effects of redshift space distortions on the 2point correlation function are investigated and modelled in the nonlinear and linear regimes. The 1D pairwise velocity dispersion of galaxies is measured to be 416 ± 36 kms(^1) which, while being consistent with the canonical value of ~ 350 kms(^1) is slightly smaller than recently measured values. However, this value is inconsistent with the ~ 1000 kms(^1) value as measured in the standard cold dark matter cosmological model at a high level of significance. The ratio of the mean mass density of the Universe, Ω, and the linear bias factor, b (relating the galaxy and light distributions), is then calculated to be Ω(^0.6)/b = 0.45 ± 0.38. This favours either an open (Ω < 1) and unbiased (b = 1) Universe or a flat (Ω = 1) and biased (b ~ 2) Universe.
