Massive Galaxy Clusters at High-redshift from the Spitzer SpARCS Survey

We propose XMMNewton EPIC observations of a sample of four high redshift galaxyclusters with 0.87 < z < 1.20 discovered by the 42 square degree SpitzerAdaptation of the Red Sequence Survey (SpARCS). This survey is currently thelargest optical/IR survey for high redshift clusters, and includes significantmultiwavelength followup. Extensive Gemini spectroscopic observations haveconfirmed that all of our targets are rich, massive clusters with velocitydispersions ranging from 550800 km/sec. Our XMM observations are designed todetect the extended intracluster medium in the cluster cores, provide firstestimates of cluster Xray luminosities, and broadly investigate the core gasdensities of our targets. truncated!, Please see actual data for full text [truncated!, Please see actual data for full text]