The Planck Cluster Cosmological Sample

The Planck Cosmological Reference Sample of 189 SZselected provides theopportunity to define the low redshift benchmark for cluster evolution studies.To completely characterize the sample requires 12 XMMNewton observations, eachsufficient to measure the key mass proxy M_{YX} to an accuracy of 5% or better.In addition, the observations will enable detailed studies of cluster scalingrelations, measurement of the scatter around these relations, and enableimprovements in the Planck SZ measurements using accurate Xray determinedpositions and sizes. The ultimate goal is to compare high z and low z clustersamples to constrain cosmological parameters as well as to understand anydifferences between Xray and SZ cluster selection functions. truncated!, Please see actual data for full text [truncated!, Please see actual data for full text]