The present project is related to the study of galaxy clusters, to their formation and to the physical processes that are leading their evolution. In the hierarchical model of structure formation, clusters of galaxies form by accretion and merging of smaller sub-clusters and groups.
We aim at answering to open questions about the dynamical and physical processes that act during the merging event on each component of clusters, i.e. galaxies, intra-cluster plasma and dark matter. Our two-level approach consists in:
- observing in optical, X-ray and radio a sample of interacting clusters; and
- reproducing by N-body and hydrodynamic simulations the evolution of collisionless matter (i.e. galaxies and dark matter) and intra-cluster gas respectively.
A detailed modelling of cluster merger is very difficult at present; by comparing multi-wavelength observations to numerical simulations, we will be able to determine the stage and the geometry of merging clusters. In this way, we will obtain a sequence of clusters in different phases of the merging process; this sample will be the starting point to follow the evolution of cluster properties during their growth from poor groups to rich galaxy systems.
In particular, we aim at analyzing how the process of cluster formation acts on the following: the relative distributions of galaxies, gas and dark matter; the large scale structure of clusters; both thermal and non-thermal components of the intra-cluster plasma, observable at X-ray and radio wavelengths respectively; the dynamics and kinematics of the member galaxies, and their internal properties, e.g. star formation rate and AGN activity.
As clusters of galaxies are the largest organized structures in the Universe, a clear and complete picture of cluster evolution will bring fundamental clues on cosmological models and structure formation.
Call for proposal
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