X-ray, SZ and dark matter in galaxy clusters
Galaxy clusters are dark-matter dominated systems enclosed in a volume that is a high-density microcosm of the rest of the universe. What is their true mass scale? What are the statistical properties of the representative population? How does their detectability depend on baryon physics? We have learned a lot on these fundamental questions with our current projects, like XMM-Newton Cluster Outskirts Project (X-COP) and CLASH. More has to be understood and will be the focus of our next XMM-Newton Heritage Cluster Project that will pave the way in using the next generation of observatories, like XRISM SKA Athena, to construct a consistent picture of the formation and composition of galaxy clusters.