Cluster scaling and its redshift evolution from XMM-Newton
  We put together the results of XMM-Newton observations of a number of representative group and cluster samples at low and high redshifts. These results confirm the entropy ramp as an explanation of the observed scaling relations. We observe a mild evolution in the entropy of clusters. The observed degree of evolution is consistent with expectations of the shock heating at a fixed overdensity (500) with respect to the critical density in LCDM. The study of the evolution in the pressure scaling imposes strong requirements in the definition of the average temperature of the cluster. The scaling temperature should be consistent to better than the 10% level. Once such a consistency is achieved, no additional evolution in the pressure has been detected in addition to the prediction of the shock heating in the LCDM Universe. 
A. Finoguenov, H. Boehringer, J. P. F. Osmond, T. J. Ponman, A. J. R.   Sanderson, Y.-Y. Zhang, M. Zimer