Cathy Horellou will hold her professor installation lecture. The title is "Galaxy clusters and cosmology: a submillimeter-to-radio vision".

Abstract

Clusters of galaxies are the largest self-gravitating structures in the Universe and they are important cosmological probes. Traditionally, they have been the domain of optical/near-infrared and X-ray astronomy. The last few years have seen a tremendous increase of observations in the submillimeter-to-radio part of the electromagnetic spectrum. Observations reveal both the individual cluster member galaxies and the diffuse, thin and hot intracluster plasma. The two relevant physical processes are the Sunyaev-Zel'dovich effect (SZE), which is an interaction between cold (3 K) photons from the cosmic  microwave background and hot (10 million K) electrons in the cluster, and synchrotron emission due to relativistic electrons spiraling along magnetic field lines. Interestingly, the SZE is mostly independent of distance, making it a promising tool to detect distant clusters. The number of distant clusters is sensitive to cosmological parameters.

She will review recent observations of galaxy clusters in the submillimeter-to-radio waveband and describe how future observations, for instance with the newly commissioned LOw Frequency ARray (LOFAR), will contribute to this rapidly developing field.