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We investigate the effect of redshift-space distortions in the power spectrum parallel and perpendicular to the observers line of sight, P(k_par,k_perp), using the optically selected Durham/UKST Galaxy Redshift Survey. On small, non-linear scales anisotropy in the power-spectrum is dominated by the galaxy velocity dispersion; the `Finger of God effect. On larger, linear scales coherent peculiar velocities due to the infall of galaxies into overdense regions are the main cause of anisotropy. According to gravitational instability theory these distortions depend only on the density and bias parameters via beta. Geometrical distortions also occur if the wrong cosmology is assumed, although these would be relatively small given the low redshift of the survey. To quantify these effects, we assume the real-space power spectrum of the APM Galaxy Survey, and fit a simple model for the redshift-space and geometrical distortions. Assuming a flat Omega = 1 universe, we find values for the one-dimensional pairwise velocity dispersion of sigma_p = 410 +- 170 km/s, and beta = 0.38 +- 0.17. An open Omega = 0.3, and a flat Omega = 0.3, Lambda = 0.7 universe yield sigma_p = 420 km/s, beta = 0.40, and sigma_p = 440 km/s, beta = 0.45 respectively, with comparable errors. These results are consistent with estimates using the two-point galaxy correlation function, xi(sigma,pi), and favour either a low-density universe with Omega ~ 0.3 if galaxies trace the underlying mass distribution, or a bias factor of b ~ 2.5 if Omega = 1.
Future high spectroscopic resolution galaxy surveys will observe galaxies with nearly full-sky footprints. Modeling the galaxy clustering for these surveys, therefore, must include the wide-angle effect with narrow redshift binning. In particular, wh
We analyse the redshift-space (z-space) distortions of QSO clustering in the 2dF QSO Redshift Survey (2QZ). To interpret the z-space correlation function, xi(sigma,pi), we require an accurate model for the QSO real-space correlation function, xi(r).
We study an efficient way to enhance the measurability of the galaxy density and/or velocity power spectrum in redshift space. It is based on the angular decomposition with the Tripolar spherical harmonic (TripoSH) basis and applicable even to galaxy
We analyse the anisotropic clustering of the Baryon Oscillation Spectroscopic Survey (BOSS) CMASS Data Release 11 (DR11) sample, which consists of $690,827$ galaxies in the redshift range $0.43 < z < 0.7$ and has a sky coverage of $8,498,text{deg}^2$
We present the measurement and interpretation of the angular power spectrum of nearby galaxies in the 2MASS Redshift Survey catalog with spectroscopic redshifts up to $zapprox 0.1$. We detect the angular power spectrum up to a multipole of $ellapprox