The Physical Properties of the Intra-Cluster Gas at z > 1

We propose deep EPIC observations of two Xray selected spectroscopically confirmed, clusters at z1.10 and z1.23. High S/N Xray imaging and spectroscopy will allow us to measure, for the first time, both the temperature and the metallicity of the intracluster gas in two bonafide clusters at z>1, with unprecented insight in their physical properties.Given the large lookback time, these measurements: 1. will yield an estimate of the cluster masses with direct implications on cosmological models; 2. will permit to study evolutionary effects on the cluster LxT relation; 3. will also constrain the mode and epoch of metal enrichment of the gas. truncated!, Please see actual data for full text [truncated!, Please see actual data for full text]