Cluster abundance and large-scale structure
Journal
Monthly Notices of the Royal Astronomical Society
Journal Volume
327
Journal Issue
2
Pages
629-638
Date Issued
2001
Author(s)
Wu, J.-H.P.
Abstract
We use the presently observed number density of X-ray clusters and the linear mass power spectra to constrain the amplitude of matter density perturbations on the scale of 8 h?1 Mpc (�m8) and the redshift distortion parameter (�]), in various background cosmologies. The best fit to the observed mass power spectra gives a spectral index and a shape parameter , with the theoretically expected degeneracy (all at the 95 per cent confidence level). These are consistent with the recent cosmic microwave background (CMB) results. We then calculate the cluster-abundance-normalized �m8, using different models of mass function: Press & Schechter (PS), Sheth & Tormen (ST) and Lee & Shandarin (LS) . The �m8 based on non-spherical models (ST and LS) are significantly lower, mainly because of the larger mass function on the cluster scales. In particular, we find , where In our analysis, we also derive the probability distribution function of cluster formation redshift using the Lacey�VCole formalism, but with modifications to incorporate non-spherical collapse. The origins of the uncertainties in our �m8 results are investigated in detail, with the main contributor being the normalization in the virial mass�Vtemperature relation. From the Point Source Catalogue Redshift Survey (PSCz) power spectrum alone and using the above �F�� as the prior, we also obtain (at 95 per cent confidence level) for the IRAS galaxies. By combining this with the �m8 result, we obtain This is more consistent with the recent observations than the result based on the PS formalism, which is higher.
Type
journal article