The 2dF Galaxy Redshift Survey is the first to observe more than 100,000 redshifts , making possible precise measurements of many aspects of galaxy clustering .
The spatial distribution of galaxies can be studied as a function of galaxy spectral type , and also of broad-band colour .
Redshift-space distortions are detected with a high degree of significance , confirming the detailed Kaiser distortion from large-scale infall velocities , and measuring the distortion parameter \beta \equiv \Omega _ { m } ^ { 0.6 } / b = 0.49 \pm 0.09 .
The power spectrum is measured to \mathrel { \lower 2.58 pt \hbox { $ \buildrel { \textstyle < } \over { \scriptstyle \sim } $ } } 10 \% accuracy for k > 0.02 { h Mpc ^ { -1 } } , and is well fitted by a CDM model with \Omega _ { m } h = 0.18 \pm 0.02 and a baryon fraction of 0.17 \pm 0.06 .
A joint analysis with CMB data requires \Omega _ { m } = 0.31 \pm 0.05 and h = 0.67 \pm 0.04 , assuming scalar fluctuations .
The fluctuation amplitude from the CMB is \sigma _ { 8 } = 0.76 \pm 0.04 , assuming reionization at z \mathrel { \lower 2.58 pt \hbox { $ \buildrel { \textstyle < } \over { \scriptstyle \sim } $ } } 10 , so that the general level of galaxy clustering is approximately unbiased , in agreement with an internal bispectrum analysis .
Luminosity dependence of clustering is however detected at high significance , and is well described by a relative bias of b / b ^ { * } = 0.85 + 0.15 ( L / L ^ { * } ) .
This is consistent with the observation that L ^ { * } in rich clusters is brighter than the global value by 0.28 \pm 0.08 mag .