Modeling the Alignment Profile of Satellite Galaxies in Clusters

Abstract

Analyzing the halo and galaxy catalogs from the Millennium simulations at redshifts $z=0,0.5,1$, we determine the alignment profiles of cluster galaxies by measuring the average alignments between the major axes of the pseudo inertia tensors from all satellites within cluster's virial radius and from only those satellites within some smaller radius as a function of the top-hat scale difference. The alignment profiles quantify how well the satellite galaxies retain the memory of the external tidal fields after merging into their host clusters and how fast they lose the initial alignment tendency as the cluster's relaxation proceeds. It is found that the alignment profile drops faster at higher redshifts and on smaller mass scales. This result is consistent with the picture that the faster merging of the satellites and earlier onset of the nonlinear effect inside clusters tend to break the preferential alignments of the satellites with the external tidal fields. Modeling the alignment profile of cluster galaxies as a power-law of the density correlation coefficient that is independent of the power spectrum normalization (${\sigma }_8$) and demonstrating that the density correlation coefficient varies sensitively with the density parameter (${\Omega }_m$) and neutrino mass fraction ($f_{\nu }$), we suggest that the alignment profile of cluster galaxies might be useful for breaking the ${\Omega }_m$-${\sigma }_8$ and $f_{\nu }$-${\sigma }_8$ degeneracies.

accepted for publication in ApJ, Introduction and Conclusion sections improved, mistakes in plotting the figures corrected, detailed explanations for the dependence of the alignment profiles on the mass and redshift provided, 7 figures, 3 tables

References in corpus (30)

• Massive neutrinos and cosmology
• Why your model parameter confidences might be too optimistic -- unbiased estimation of the inverse covariance matrix
• The persistent cosmic web and its filamentary structure I: Theory and implementation
• A GMBCG Galaxy Cluster Catalog of 55,424 Rich Clusters from SDSS DR7
• The Evolution of Dark Matter Halo Properties in Clusters, Filaments, Sheets and Voids
• Multiscale Phenomenology of the Cosmic Web
• The spin and orientation of dark matter halos within cosmic filaments
• The Shape of Dark Matter Haloes in the Aquarius Simulations: Evolution and Memory
• Impact of massive neutrinos on nonlinear matter power spectrum
• Internal properties and environments of dark matter halos
• The Alignments of the Galaxy Spins with the Real-Space Tidal Field Reconstructed from the Two Mass Redshift Survey
• Effects of Massive Neutrinos on the Large-Scale Structure of the Universe
• The Influence of Large-Scale Structure on Halo Shapes and Alignments
• Alignment between galaxies and large-scale structure
• The orientation of disk galaxies around large cosmic voids
• Spatial and kinematic alignments between central and satellite halos
• Void Ellipticity Distribution as a Probe of Cosmology
• Alignments of Galaxy Group Shapes with Large Scale Structure
• Intrinsic Alignment of Cluster Galaxies: the Redshift Evolution
• Global and Local Effects of Rotation: Observational Aspects
• On the Intrinsic Alignments of the Late-Type Spiral Galaxies from the Sloan Digital Sky Survey Data Release 7
• The multi-stream flows and the dynamics of the cosmic web
• The Effect of Coupled Dark Energy on the Alignment between Dark Matter and Galaxy Distributions in Clusters
• Alignments of Group Galaxies with Neighboring Groups
• The Orientation of Galaxies in Galaxy Clusters
• Connected structure in the 2dFGRS
• The geometry of the filamentary environment of galaxy clusters
• Numerical Simulations Unravel the Cosmic Web
• Alignment of Galaxies and Clusters
• The Anisotropic Two-Point Correlation Functions of the Nonlinear Traceless Tidal Field in the Principal-Axis Frame

Cited by in corpus (6)

• Galaxy and Mass Assembly (GAMA): galaxy radial alignments in GAMA groups
• Projected alignment of non-sphericities of stellar, gas, and dark matter distributions in galaxy clusters: analysis of the Horizon-AGN simulation
• Investigation of the orientation of galaxies in clusters: the importance, methods and results of research
• The distribution of galaxies gravitational field stemming from their tidal interaction
• Orientation of galaxies in structures
• Massive Neutrinos Promote the Size Growth of Early-Type Galaxies