Galaxy clustering and the origin of large-scale flows

Abstract

view Abstract Citations (9) References (18) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Galaxy Clustering and the Origin of Large-Scale Flows Juszkiewicz, R. ; Yahil, A. Abstract Peebles's "cosmic virial theorem" is extended from its original range of validity at small separations, where hydrostatic equilibrium holds, to large separations, in which linear gravitational instability theory applies. The rms pairwise velocity difference at separation r, C(v_1_ - v_2_)^2^>, is shown to depend on the spatial galaxy correlation function ξ(x) only for x < r. Gravitational instability theory can therefore be tested by comparing the two up to the maximum separation for which both can reliably be determined, and there is no dependence on the poorly known large-scale density and velocity fields. The extant data show a significant systematic difference between the velocity data for elliptical and spiral galaxies, probably due to insufficient depth and sky coverage. At this stage, it is therefore only possible to restrict the cosmological density parameter to the range 0.1 <~ {OMEGA} <~ 1. With the expected improvement in the data over the next few years, however, our method should yield a reliable determination of {OMEGA}. Publication: The Astrophysical Journal Pub Date: November 1989 DOI: 10.1086/185576 Bibcode: 1989ApJ...346L..49J Keywords: Cosmology; Galactic Clusters; Gravitational Effects; Universe; Computational Astrophysics; Elliptical Galaxies; Perturbation Theory; Spatial Distribution; Spiral Galaxies; Velocity Distribution; Astrophysics; EARLY UNIVERSE; GALAXIES: CLUSTERING full text sources ADS |