The kinematics and observable properties of AGN jets and cavities with cosmological simulations

Most of the ordinary matter of Galaxy Clusters is in the form of a rarefied and ionized gas, called the Intra Cluster Medium (ICM). The ICM is believed to be constantly in motion, mainly due to turbulence. This thesis analyzes an highly resolved cosmological simulation of the gas dynamics of a single galaxy cluster, which included several dynamical effects for the realistic evolution of the ICM: gravity, matter accretions, shock waves, turbulence, magnetic fields and a central Active Galactic Nucleus (AGN). The AGN has been resimulated five different times by modifying the power of its jets. This promotes the onset of a different long-term dynamics of the ICM. Once the jets are injected, they release relativistic electrons. It is possible to follow the trajectories of such particles through tracers, that are tracked from the beginning to the end of the simulation to study the dynamics they are subject to throughout the life of the cluster. The first purpose of this Thesis is to establish how much intracluster volume can be typically refilled by relativistic electrons expelled by jets, the electrons kinematics and the dependency between jet power and the kinematic of tracers. The second purpose of this thesis is to produce a systematic comparison between observable-like estimates of the age and energetics of X-ray cavities produced by AGN in clusters, and their true value in the simulation. To this end, I analysed X-ray maps in a way that is as similar as possible to the procedure adopted in the real observations. The statistical results of cosmological simulations are also compared with the results obtained by analyzing a second fully idealized simulation, to assess to which extend can my result be affected by specific choices in the assumed numerical and physical setup.