The Kinematics of Dense Clusters of Galaxies. III. Comparison With Cosmological Models
Abstract
We compare the combined distribution of 31 group and 25 cluster velocity dispersions [Zabludoff et al., AJ, 106, 1301(1993)] with the ensemble of 32 models for the formation and evolution of large-scale structure examined by Weinberg & Cole [MNRAS, 259, 652 (1992)]. The models include Gaussian and non-Gaussian initial fluctuations, different power law spectra (n = - 1, n = 0, n = -2, "pancake"), flat ({OMEGA} = 1) and open ({OMEGA} = 0.2) cosmologies, and unbiased (b_8_ = 1) and biased (b_8_ = 2) galaxy formation. The set of initial conditions we test, although limited, samples enough parameter space to indicate which general classes of models are consistent with the data. The two Gaussian, n = - 1 models which best approximate the standard and open Cold Dark Matter (CDM) models do not match the observed distribution of velocity dispersions; models with b_8_ = 2 and {OMEGA} = 1 ("standard") or b_8_ = 1 and {OMEGA} = 0.2 ("open") predict too large a ratio of low to high velocity dispersion systems. A "COBE-normalized" CDM model with b_8_ = 1 and {OMEGA} = 1 produces clusters with velocity dispersions higher than those measured. All three models overestimate the total abundance of systems.
- Publication:
-
The Astronomical Journal
- Pub Date:
- June 1994
- DOI:
- 10.1086/117004
- Bibcode:
- 1994AJ....107.1929Z
- Keywords:
-
- Astronomical Models;
- Galactic Clusters;
- Red Shift;
- Spiral Galaxies;
- Star Distribution;
- Dark Matter;
- Galactic Evolution;
- Galactic Structure;
- Mass Distribution;
- Astrophysics;
- LARGE-SCALE STRUCURE OF THE UNIVERSE;
- GALAXIES: CLUSTERING