Local mean mass density of the universe: new methods for studying galaxy clustering

Journal Article · Sat Apr 01 04:00:00 EST 1978 · Astrophys. J.; (United States)

DOI:https://doi.org/10.1086/156000· OSTI ID:6931049

Davis, M; Geller, M J; Huchra, J

We analyze a catalog of galaxy redshifts nearly complete to a limiting blue magnitude of 13.0 and covering the entire sky. We obtain estimates of the galaxy luminosity function and of the local mean mass density. Our best estimate of the luminosity density is L=1.2 x 10/sup 8/hL/sub sun/ Mpc/sup -/3 (h is Hubble's constant in units of 100 km s/sup -/1 Mpc/sup -/1).The redshift catalog is also the basis for three estimators of the spatial correlation function for the galaxy distribution. We reexamine the well-studied angular correlation function and we define and explore two new redshift-weighted measures of the distribution. These estimators lead to a revised value for the amplitude of the spatial correlation function xi ('ir) = (r/sub c//r)/sup ..gamma../. We find r/sub c/approx. =3h/sup -/1 Mpc, almost a factor of 2 less than the estimates from previous calculations. We also measure the one-dimensional rms relative peculiar velocity dispersion (..delta..v/sup 2/(r))/sup 1/2/, and we find (..delta..v/sup 2/(r))/sup 1/2/approx. =300 +- 30 km s/sup -/1 nearly independent of separation r.Cosmic virial theorems which are cast in terms of the correlation functions and the peculiar velocity dispersion are used to estimate the contribution, ..cap omega../sub G/, of matter associated with galaxies to the critical density. The statistical virial theorems suggest 0.2< or approx. =approx. =/sub G/< or approx. =0.7.

• Research Organization: Harvard-Smithsonian Center for Astrophysics
• OSTI ID: 6931049
• Journal Information: Astrophys. J.; (United States), Journal Name: Astrophys. J.; (United States) Vol. 221:1; ISSN ASJOA
• Country of Publication: United States
• Language: English

Related Subjects

640106* -- Astrophysics &amp; Cosmology-- Cosmology
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
COSMOLOGICAL MODELS
DISTRIBUTION
FUNDAMENTAL CONSTANTS
GALAXY CLUSTERS
LUMINOSITY
MATHEMATICAL MODELS
MATHEMATICS
OPTICAL PROPERTIES
PHYSICAL PROPERTIES
RED SHIFT
SPATIAL DISTRIBUTION
STATISTICS
UNIVERSE
VIRIAL THEOREM