Evolution of X-ray galaxy Cluster Properties in a Representative Sample (EXCPReS). Optimal binning for temperature profile extraction

We present XMM-Newton observations of a representative X-ray selected sample of 31 galaxy clusters at moderate redshift (0.4 < z < 0.6), spanning the mass range 10 14 < M 500 < 10 15 M ⊙ . This sample, EXCPReS (Evolution of X-ray galaxy Cluster Properties in a Representative Sample), is used to test and validate a new method to produce optimally-binned cluster X-ray temperature profiles. The method uses a dynamic programming algorithm, based on partitioning of the soft-band X-ray surface brightness profile, to obtain a binning scheme that optimally fulfils a given signal-to-noise threshold criterion out to large radius. From the resulting optimally-binned EXCPReS temperature profiles, and combining with those from the local REXCESS sample, we provide a generic scaling relation between the relative error on the temperature and the [0.3–2] keV surface brightness signal-to-noise ratio, and its dependence on temperature and redshift. We derive an average scaled 3D temperature profile for the sample. Comparing to the average scaled 3D temperature profiles from REXCESS , we find no evidence for evolution of the average profile shape within the redshift range that we probe.