Semianalytic Predictions for Statistical Properties of X-Ray Clusters of Galaxies in Cold Dark Matter Universes
Abstract
Temperature and luminosity functions of X-ray clusters are computed semianalytically, combining a simple model for the cluster gas properties with the distribution functions of halo formation epochs proposed by Lacey & Cole and Kitayama & Suto. In contrast to several previous approaches that apply the Press-Schechter mass function in a straightforward manner, our method can take into account explicitly the temperature and luminosity evolution of clusters. In order to make quantitative predictions in a specific cosmological context, we adopt cold dark matter universes. Assuming the baryon density parameter {OMEGA}_B_ = 0.0125 h^-2^ (h is the Hubble constant in units of 100 km s^-1^ Mpc^-1^) and the COBE normalization of matter fluctuations, temperature and luminosity functions of X-ray clusters depend sensitively on the density parameter {OMEGA}_0_. Allowing for several uncertainties in observational data as well as in our simplified assumptions, we conclude that {OMEGA}_0_ ~ 0.2- 0.5 and h ~ 0.7 CDM models with/without the cosmological constant reproduce simultaneously the observed temperature and luminosity functions of X-ray clusters at redshift z ~ 0.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- October 1996
- DOI:
- 10.1086/177797
- arXiv:
- arXiv:astro-ph/9604141
- Bibcode:
- 1996ApJ...469..480K
- Keywords:
-
- COSMOLOGY: THEORY;
- COSMOLOGY: DARK MATTER;
- GALAXIES: CLUSTERS: GENERAL;
- X-RAYS: GALAXIES;
- Astrophysics
- E-Print:
- 21 pages, uuencode, gzipped tar file including LaTeX text and 11 postscript figures. Accepted for publication in Astrophysical Journal. (Figures are slightly modified from the original version.)