Sunyaev-Zel'dovich galaxy clusters number counts : consequences of cluster scaling laws evolution

TL;DR

This paper predicts Sunyaev-Zeldovich effect galaxy cluster counts considering cluster evolution and non-gravitational processes, highlighting their impact on cosmological measurements and the importance of ongoing surveys.

Contribution

It introduces a model incorporating non-gravitational physics into cluster scaling laws, affecting SZE counts and their redshift distribution, and uses MCMC to combine multiple cosmological data sets.

Findings

Models with evolving cluster scaling laws predict fewer high-redshift SZE clusters.

Ongoing SZE surveys can test non-gravitational physics in cluster evolution.

Cluster abundance evolution challenges standard cosmological assumptions.

Abstract

Galaxy cluster surveys based on the Sunyaev-Zeldovich effect (SZE) mapping are expected from ongoing experiments. Such surveys are anticipated to provide a significant amount of information relevant to cosmology from the number counts redshift distribution. We carry out an estimation of predicted SZE counts and their redshift distribution taking into account the current cosmological constraints and the X-ray cluster temperature distribution functions. Comparison between local and distant cluster temperature distribution functions provides evidence for an evolution in the abundance of X-ray clusters that is not consistent with the use of standard scaling relations of cluster properties in the framework of the current concordance model. The hypothesis of some evolution of the scaling law driven by non-gravitational processes is a natural solution to this problem. We perform a MCMC statistical study using COSMOMC, combining current CMB observations from WMAP, the SNIa Hubble diagram, the galaxy power spectrum data from SDSS and X-ray clusters temperature distributions to predict SZE cluster number counts. Models reproducing well the X-ray cluster temperature distribution function evolution lead to a significantly lower SZE clusters number counts with a distinctive redshift distribution. Ongoing microwave SZE surveys will therefore shed new light on intracluster gas physics and greatly help to identify the role of possible non-gravitational physics in the history of the hot gas component of x-ray clusters.