Joint radio and X-ray analysis of powerful feedback systems

Le résumé fourni par la source

Galaxy clusters are the most massive bound objects in the universe. Roughly 90% of the baryons in clusters reside in the hot plasma of the intracluster medium (ICM), while the rest form stars in galaxies. Active galactic nuclei (AGN) that appear in the centers of galaxy clusters are the most energetic objects in the Universe. The central engine of an AGN is a compact supermassive black hole (SMBH), whose strong gravitational field traps not only matter but also light. AGN feedback refers to the process of interaction between the energy injected by relativistic jets originating near SMBHs and the surrounding ICM. In this thesis we combine X-ray and radio observations in order to study the profound effect the tiny, but powerful SMBH has on the observed morphology of the ICM. This thesis contains four chapters, including an introduction on the interaction between the ICM and the central SMBH. In Chapter 2 we present a new analysis of the widely used relation between cavity power and radio luminosity in clusters of galaxies with evidence for strong AGN feedback. We also examine the morphology of a subset of four well-resolved sources with MSSS. In Chapter 3 we analyze AGN activity signatures in the rich nearby galaxy cluster Abell 1795 aiming to confirm and characterize the long-term feedback history in the system. Chapter 4 presents a new radio spectral-aging analysis of the powerful FR II radio galaxy Cygnus A.

Ce résumé expose les affirmations des auteurs. BNTIC ne l’interprète pas comme une validation indépendante des résultats.