1997/11/04 by Michael Groß, Michael A. K. Gross, Gross, Michael A. K. +10
Physics and Astronomy · #Astronomy and Astrophysical Research #Astrophysics (astro-ph) #FOS: Physical sciences #Galaxies: Formation, Evolution, Phenomena #Stellar, planetary, and galactic studies #astro-ph
paper · pdf · doi:10.48550/arxiv.astro-ph/9711035
4 pages Latex using sprocl.sty, 1 figure. To appear in Proceedings of 12th Potsdam Cosmology Workshop, "Large-Scale Structure: Tracks and Traces" Sept. 15-19, 1997
arxiv created 1997/11/04 · openalex publication_date 1997/11/04 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
The combination of measurements of the local abundance of rich clusters of galaxies and its evolution to higher redshift offers the possibility of a direct measurement of Ω0 with little contribution from other cosmological parameters. We investigate the significance of recent claims that this evolution indicates that Ω0 must be small. The most recent cluster velocity dispersion function from a compilation including the ESO Northern Abell Cluster Survey (ENACS) results in a significantly higher normalization for models, corresponding to σ8≈ 0.6 for Ω0=1, compared to the Eke, Cole, & Frenk result of σ8=0.52± 0.04. Using the ENACS data for a z=0 calibration results in strong evolution in the abundance of clusters, and we find that the velocity dispersion function is consistent with Ω0=1. The results are dependent upon the choice and analysis of low-redshift and high-redshift data, so at present, the data is not good enough to determine Ω0 unambiguously.