Modeling non-linear effects in the redshift space two-point correlation function and its implications for the pairwise velocity dispersion

Abstract

The anisotropies in the galaxy two-point correlation function measured from redshift surveys exhibits deviations from the predictions of the linear theory of redshift space distortion on scales as large 20 Mpc/h where we expect linear theory to hold in real space. Any attempt at analyzing the anisotropies in the redshift correlation function and determining the linear distortion parameter βrequires these deviations to be correctly modeled and taken into account. These deviations are usually attributed to galaxy random motions and these are incorporated in the analysis through a phenomenological model where the linear redshift correlation is convolved with the random pairwise velocity distribution function along the line of sight. We show that a substantial part of the deviations arise from non-linear effects in the mapping from real to redshift space caused by the coherent flows. Models which incorporate this effect provide a better fit to N-body results as compared to the phenomenological model which has only the effect of random motions. We find that the pairwise velocity dispersion predicted by all the models that we have considered are in excess of the values determined directly from the N-body simulations. This indicates a shortcoming in our understanding of the statistical properties of peculiar velocities and their relation to redshift distortion.

Minor Revisions, Accepted to MNRAS

References in corpus (38)

• The 2dF Galaxy Redshift Survey: correlation functions, peculiar velocities and the matter density of the Universe
• Reconstructing the linear power spectrum of cosmological mass fluctuations
• A measurement of the cosmological mass density from clustering in the 2dF Galaxy Redshift Survey
• The 2dF Galaxy Redshift Survey: The bias of galaxies and the density of the Universe
• Galaxy Clustering in Early SDSS Redshift Data
• Evolution of structure in cold dark matter universes
• Spatial correlation function and pairwise velocity dispersion of galaxies: CDM models versus the Las Campanas Survey
• Measuring the cosmological constant with redshift surveys
• Redshift-Space Distortions and the Real-Space Clustering of Different Galaxy Types
• Clustering in the 1.2 Jy IRAS Galaxy Redshift Survey II: Redshift Distortions and ξ(r_p,π)
• A Spherical Harmonic Analysis of Redshift Space
• Peculiar velocities of galaxies and clusters
• On The Validity of the Streaming Model for the Redshift-Space Correlation Function in the Linear Regime
• Nonlinear Cosmological Power Spectra in Real and Redshift--Space
• Maximum-Likelihood Comparisons of Tully-Fisher and Redshift Data: Constraints on Omega and Biasing
• Redshift space bias and beta from the halo model
• Linear and nonlinear contributions to pairwise peculiar velocities
• The redshift space power spectrum in the halo model
• PAIRWISE VELOCITIES OF GALAXIES IN THE CFA AND SSRS2 REDSHIFT SURVEYS
• Can Baryonic Features Produce the Observed 100 Mpc Clustering?
• Modelling the redshift-space distortion of galaxy clustering
• Analytical Approximations to the Low-Order Statistics of Dark Matter Distribution
• Power Spectrum Analysis of the Stromlo-APM Redshift Survey
• The Nonlinear Redshift Space Power Spectrum: Omega from Redshift Surveys
• An analytical model for the non-linear redshift-space power spectrum
• Cold Dark Matter II: Spatial and Velocity Statistics
• The Durham/UKST Galaxy Redshift Survey - IV. Redshift Space Distortions via the 2-Point Correlation Function
• The Pairwise Velocity Distribution of Galaxies in the Las Campanas Redshift Survey
• Estimating beta from redshift-space distortions in the 2dF galaxy survey
• The Galaxy Pairwise Velocity Dispersion as a Function of Local Density
• Estimating Omega from Galaxy Redshifts: Linear Flow Distortions and Nonlinear Clustering
• A Reanalysis of Small Scale Velocity Dispersion in the CfA1 Survey
• Nonlinear redshift distortions: The two-point correlation function
• Scaling properties of the redshift power spectrum: theoretical models
• The Pairwise Peculiar Velocity Dispersion of Galaxies: Effects of the Infall
• The Small Scale Velocity Dispersion of Galaxies: A Comparison of Cosmological Simulations
• Self-similarity and the Pair Velocity Dispersion
• The pair-wise velocity dispersion of galaxies: effects of non radial motions

Cited by in corpus (5)

• De-contamination of cosmological 21-cm maps
• Distribution function approach to redshift space distortions. Part II: N-body simulations
• How to generate a significant effective temperature for cold dark matter, from first principles
• Large-Scale Non-Gaussianities in the 21 cm Background Anisotropies From the Era of Reionization
• A universal bound on Quantum Chaos from Random Matrix Theory