Galaxy Clusters and Cold Dark Matter: A Low-Density Unbiased Universe?
Abstract
Large-scale (L = 400 h^-1^ Mpc) simulations of a universe dominated by cold dark matter (CDM) are tested against two fundamental properties of clusters of galaxies: the cluster mass function and the cluster correlation function. We find that standard biased CDM models ({OMEGA} = 1) are inconsistent with these observations for any bias parameter b. A low-density, low-bias ({OMEGA} ~ 0.25, b ~ 1) CDM-type model, with or without a cosmological constant, appears to be consistent with both the cluster mass function and the cluster correlations. The low-density model agrees well with the observed correlation function of the Abell, Automatic Plate Measuring Facility (APM), and Edinburgh-Durham cluster catalogs. The model is in excellent agreement with the observed dependence of the correlation strength on cluster mean separation reproducing the measured universal dimensionless cluster correlation, ξ_cc_ = 0.2(r/d)^-1.8^. The low-density model is also consistent with other large-scale structure observations, including the APM angular galaxy correlations, and for {DELTA} = 1 - {OMEGA}, with the COBE results of the microwave background radiation fluctuations.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- October 1992
- DOI:
- 10.1086/186582
- Bibcode:
- 1992ApJ...398L..81B
- Keywords:
-
- Astronomical Catalogs;
- Astronomical Models;
- Dark Matter;
- Galactic Clusters;
- Background Radiation;
- Cosmic Background Explorer Satellite;
- Microwave Spectra;
- Astrophysics;
- COSMOLOGY: DARK MATTER;
- COSMOLOGY: THEORY;
- GALAXIES: CLUSTERING;
- COSMOLOGY: LARGE-SCALE STRUCTURE OF UNIVERSE;
- METHODS: NUMERICAL