Massive galaxy clusters: from relaxed to highly substructured

Galaxy clusters are important in cosmology to set constraints on various parameters, but they are also intrinsically interesting, since they allow to study many physical processes. The DAFT/FADA survey of 90 clusters in the redshift range 0.4<z<0.9 has allowed us to analyse several aspects of clusters, linked with their formation. We will present here our search for substructuring and its variation with redshift. For subsamples of clusters, we will also discuss the galaxy luminosity functions as a function of redshift and galaxy type, and the matter distribution, both within the clusters based on weak lensing and in the cluster surroundings based on galaxy density maps.

As an example of a nearby relaxed cluster, we will present recentresults on Ophiuchus, the second brightest cluster in X-rays, but which until now was not well known at optical wavelengths due to its low Galactic latitude.

01/03/2016 - 12:30
Florence Durret
Institut d'Astrophysique de Paris