Clusters of Galaxies
Clusters of galaxies are the largest overdense structures in the Universe. Their formation and evolution is tightly connected to the expansion history and the growth of large scale structures in the Universe. This connection makes them exquisite probes for cosmological models. In particular they are well suited to distinguish dark energy from modified gravity models. However this requires a good understanding of the relation between the mass of a cluster and the observable. In addition the selection of clusters given by a particular survey plays an important role. In the group here we exploit various surveys, like the Dark Energy Survey (DES), Planck, eRosita and the future Satellite mission Euclid to observe galaxy clusters and constrain cosmological models with them.
Galaxy Cluster MACS J0717 (Credit: NASA, ESA,
CXC,C. Ma, H. Ebeling, and E. Barrett (University
of Hawaii/IfA), et al., and STScI)