Ricerc@Sapienza

Clusters of galaxies are useful tools to constrain cosmological parameters but only when we have a correct knowledge of all systematics contributing to total mass estimate. Currently, the studies of the CMB primary anisotropies and the clusters abundance derive inconsistent results. In fact, inaccurate inferred cluster masses could induce biased cosmological results, see as an example the wrong cluster number count. To alleviate this tension it is critical to estimate the cluster total mass having a good control of the mass bias induced by the difference between the true mass of clusters and the mass, inferred by using hydrostatic equilibrium (HE) approximation and/or the virial theorem and/or galaxies kinematics and/or background sources lensing effect. This is among the hot topics of current cosmological studies. Multi-probe observations of clusters, i.e. observations in the optical band of the galaxies members and of background objects lensing effect, and in X-ray and millimetre bands, by the Sunyaev-Zel'dovich effect (SZ), to explore the IntraCluster Medium (ICM), allow to infer and to calibrate the mass budget.
In this Research Project we plan to deeply investigate the amount and the radial distribution of matter inside clusters of galaxies, in terms of stellar, gas and Dark Matter components by using observations and hydrodynamical simulations. We have access to high angular resolution SZ maps of 50 clusters with the mm-camera NIKA2 at 30m IRAM telescope in Spain. For the same sample of clusters, we have optical maps with the on-going optical follow-up with TNG and X-ray maps of the same objects provided by XMM satellite. In support of these observations we have access to state-of-art hydrodynamical simulations, MUSIC and The Three Hundred. Lensing data will be available with EUCLID satellite while in the meantime with HSC-Subaru observations. We plan to investigate galaxy clusters even in the presence of generalized framework of modified gravity theories.