Galaxy clustering in large redshift surveys
This thesis analyses the large scale distribution of galaxies in two recently completed redshift surveys and develops models to infer estimates of redshift-space distortions. These models demonstrate that coherent infall cannot be neglected in analyses of peculiar velocities as previous works have claimed. The clustering statistics of the largest infra-red (IR) redshift survey to date, the PSCz, are measured for the whole survey and also for various sub-samples, split by absolute luminosity and colour. It is found that IR selected galaxies are less strongly clustered than optically selected samples. A weak dependence of clustering on IR colour is found, along with a consistent dependence on IR absolute luminosity. An analysis of the 2dF Galaxy Redshift Survey (2dFGRS), containing about 220,000 galaxy redshifts, is presented. Detailed, high precision measurements are made of both the redshift- and real-space correlation functions. A comprehensive analysis of the measured 2-d correlation function leads to accurate estimates of the redshift-space distortions, including the infall parameter, beta. This measurement is then combined with other recent works to constrain the matter density of the Universe, omega. The 2dFGRS is also split by absolute luminosity and spectral type to look for dependence of clustering on these galaxy properties. A strong dependence on both luminosity and spectral type is found. The 2dF Quasar Redshift Survey (2QZ) is used, along with the 2dFGRS, to look for periodicites in the redshift distributions of QSO's in projected close galaxy-QSO pairs. Recent works have reported such an effect in small samples. No such periodicity is found in the largest, most well defined sample tested to date. These results are entirely consistent with the current cosmological paradigm of a Universe dominated by a cosmological constant and cold dark matter, and also the notion that the large scale distribution of galaxies depends on galaxy type.