Reconstruction Analysis of theIRASPoint Source Catalog Redshift Survey

Abstract

We present the results of reconstruction analysis of the galaxy distribution in a spherical region of radius 50 h-1 Mpc centered on the Local Group, as mapped by the IRAS Point Source Catalog Redshift Survey (PSCz). We reconstruct this galaxy distribution using 15 different models for structure formation in the universe, each model consisting of a set of assumptions regarding the value of the cosmological mass-density parameter Ωm and the amplitude and nature of the biasing between IRAS galaxies and the underlying mass. For every model, we also reconstruct 10 mock PSCz catalogs derived from the outputs of numerical simulations that have the appropriate values of Ωm and bias. We quantify the accuracy of a reconstruction using a variety of statistics and compare the accuracy of each reconstruction of the PSCz catalog with the accuracy expected based on the mock-catalog reconstructions of the corresponding model. We find that gravitational instability of Gaussian primordial mass-density fluctuations can account for the galaxy distribution in the PSCz catalog, at least for some plausible assumptions about the value of Ωm and the biasing between IRAS galaxies and mass. However, unbiased models in which IRAS galaxies trace mass fail to reconstruct the PSCz catalog accurately, both for Ωm = 0.4 and for Ωm = 1. Low-Ωm models in which IRAS galaxies are antibiased with respect to the mass distribution are the most successful in reconstructing the PSCz catalog. In particular, a model with Ωm = 0.4 and IRAS galaxies related to the mass distribution according to the predictions of a semianalytic galaxy formation model is very successful in reproducing the properties of the PSCz galaxy distribution.