Spatial correlation function of galaxies confronted with the theoretical scenarios

Journal Article · Wed Aug 01 04:00:00 EDT 1984 · Astrophys. J.; (United States)

DOI:https://doi.org/10.1086/161860· OSTI ID:6236367

Dekel, A; Aarseth, S J

We study the two-point spatial corrlation function of galaxies, xi(r), in a series of numerical simulations of cosmological clustering scenarios in comparison with xi(r) obtained from redshift samples. The observed excess of correlation in the range 2--10 Mpc h/sup -1/, which does not agree with a pure hierarchial clustering scenario, is reproduced in a scenario where lambda = 30 +- 5 Mpc h/sup -1/ superclusters collapse first to flat (or elongated) ''pancakes.'' The flat slope of xi(r) in that region (..gamma..<1.8) is suggested to arise from this ''pancaking,'' i.e., the transition from a 3D distribution to a 2D (or a 1D) distribution in superclusters. The correlation below 2 Mpc h/sup -1/ reflects the presence of clusters that grow from perturbations on smaller scales which are either primordial or induced by nonlinear coupling of the large-scale perturbations. A concave break at 2--3 Mpc h/sup -1/ marks the present size of rich clusters, which continues to grow gradually in comoving coordinates. The shape of xi(r) is reproduced provided that the first pancaking occurred at z< or =0.5 if ..cap omega.. = 1 and at z<2 if ..cap omega../sub 0/ = 0.1. Later, its slope becomes too steep, and indistinguishable from the one obtained in the pure clustering scenario, because the gradual clustering approaches the scale of superclusters, causing the pancakes to break up into a few huge clusters.

• Research Organization: Department of Astronomy, Yale University
• OSTI ID: 6236367
• Journal Information: Astrophys. J.; (United States), Journal Name: Astrophys. J.; (United States) Vol. 283:1; ISSN ASJOA
• Country of Publication: United States
• Language: English

Related Subjects

640105* -- Astrophysics &amp; Cosmology-- Galaxies
640106 -- Astrophysics &amp; Cosmology-- Cosmology
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
BARYONS
COSMOLOGICAL MODELS
COSMOLOGY
DISTURBANCES
ELEMENTARY PARTICLES
FERMIONS
GALAXIES
GALAXY CLUSTERS
GALAXY NUCLEI
HADRONS
LEPTONS
MANY-BODY PROBLEM
MASSLESS PARTICLES
MATHEMATICAL MODELS
NEUTRINOS
PARTICLE KINEMATICS
RED SHIFT
SIMULATION
SPECTRA
UNIVERSE