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

Delsart, ; Barbosa , D. ; Blanchard,

Astronomy and Astrophysics Review Vol. 524, Nº 81, pp. - , December, 2010.

ISSN (print): 0935-4956
ISSN (online): 1432-0754

Journal Impact Factor: 7,500 (in 2008)

Digital Object Identifier: 10.1051/0004-6361/201015234

Abstract
Aims. 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.
Methods. 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.
Results. 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.