The XMM-Newton $Ω$ Project

Bartlett, J. G.; Aghanim, N.; Arnaud, M.; Bernard, J. -Ph.; Blanchard, A.; Boer, M.; Burke, D. J.; Collins, C. A.; Giard, M.; Lumb, D. H.; Majerowicz, S.; Marty, Ph.; Neumann, D.; Nevalainen, J.; Nichol, R. C.; Pichon, C.; Romer, A. K.; Sadat, R.; Adami, C.

The XMM-Newton $Ω$ Project

Authors

Description

The abundance of high-redshift galaxy clusters depends sensitively on the matter density $\OmM$ and, to a lesser extent, on the cosmological constant $Λ$. Measurements of this abundance therefore constrain these fundamental cosmological parameters, and in a manner independent and complementary to other methods, such as observations of the cosmic microwave background and distance measurements. Cluster abundance is best measured by the X-ray temperature function, as opposed to luminosity, because temperature and mass are tightly correlated, as demonstrated by numerical simulations. Taking advantage of the sensitivity of XMM-Newton, our Guaranteed Time program aims at measuring the temperature of the highest redshift (z>0.4) SHARC clusters, with the ultimate goal of constraining both $\OmM$ and $Λ$.
To appear in the Proceedings of the XXI Moriond Conference: Galaxy Clusters and the High Redshift Universe Observed in X-rays, edited by D. Neumann, F. Durret, & J. Tran Thanh Van