On galaxy cluster sizes and temperatures
Abstract
We show that the distribution of the sizes and temperatures of clusters can be used to constrain cosmological models. The sizetemperature (ST) distribution predicted in a flat Gaussian clusterabundancenormalized Ω_{0}=0.3 model agrees well with the fairly tight ST relation observed. A larger powerspectrum amplitude σ_{8} would give rise to a larger scatter about the ST relation as would a larger value of Ω_{0} and/or long nonGaussian highdensity tails in the probability density function. For Gaussian initial conditions, the ST distribution suggests a constraint σ_{8}Ω00.26~=0.76. The ST relation is expected to get tighter at high redshifts. In the process, we derive a simple formula for the halo formationredshift distribution for nonGaussian models. We also suggest that the discrepancy between the naive zeroredshift ST relation and that observed may be owing, at least in part, to the fact that lowermass clusters form over a wider range of redshifts. An Appendix derives an equation for the formationredshift distribution of haloes.
 Publication:

Monthly Notices of the Royal Astronomical Society
 Pub Date:
 February 2001
 DOI:
 10.1046/j.13658711.2001.04185.x
 arXiv:
 arXiv:astroph/0007426
 Bibcode:
 2001MNRAS.321L...7V
 Keywords:

 GALAXIES: CLUSTERS: GENERAL;
 GALAXIES: FORMATION;
 GALAXIES: HIGHREDSHIFT;
 GALAXIES: STRUCTURE;
 COSMOLOGY: THEORY;
 galaxies: clusters: general;
 galaxies: formation;
 galaxies: highredshift;
 galaxies: structure;
 cosmology: theory;
 Astrophysics
 EPrint:
 6 pages, 7 figures