The power spectrum of galaxies in the 2dF 100k redshift survey

Abstract

We compute the real-space power spectrum and the redshift-space distortions of galaxies in the 2dF 100k galaxy redshift survey using pseudo-Karhunen-Loève eigenmodes and the stochastic bias formalism. Our results agree well with those published by the 2dFGRS team, and have the added advantage of producing easy-to-interpret uncorrelated minimum-variance measurements of the galaxy–galaxy, galaxy–velocity and velocity–velocity power spectra in 27 k-bands, with narrow and well-behaved window functions in the range 0.01 h Mpc−1 < k < 0.8 h Mpc−1. We find no significant detection of baryonic wiggles, although our results are consistent with a standard flat ΩΛ= 0.7‘concordance’ model and previous tantalizing hints of baryonic oscillations. We measure the galaxy-matter correlation coefficient r > 0.4 and the redshift-distortion parameter β= 0.49 ± 0.16 for r= 1 (β= 0.47 ± 0.16 without finger-of-god compression). Since this is an apparent-magnitude limited sample, luminosity-dependent bias may cause a slight red-tilt in the power spectrum. A battery of systematic error tests indicate that the survey is not only impressive in size, but also unusually clean, free of systematic errors at the level to which our tests are sensitive. Our measurements and window functions are available at together with the survey mask, radial selection function and uniform subsample of the survey that we have constructed.