Giulia Cerini (U. Miami): "Revisiting Galaxy Cluster Scaling Relations Through Dark Matter – Gas Coherence

Galaxy clusters are often assumed to be in hydrostatic equilibrium, with gas and member galaxies tracing the underlying gravitational potential. However, a closer examination of merging clusters compels us to reconsider the validity of such assumption. Indeed, the intricate process of cluster assembly gives rise to deviations from equilibrium, induced by a variety of physical processes, like plasma instabilities, motions of galaxies and Active Galactic Nuclei (AGN) feedback. All these non-gravitational effects play an important role in shaping the observed physical state of clusters, as also highlighted by the deviations from the ?self-similar scenario? found in observed scaling relations. Using empirically derived HST lensing mass maps and Chandra X-ray images data, in combination with OMEGA500 and IllustrisTNG simulations, we apply the Fourier analysis to study the dynamical state of galaxy clusters and cross-correlate the fluctuations of non-baryonic dark matter and hot intracluster gas. This method allows us to assess the fidelity of gas in tracing the underlying dark matter potential, thereby unlocking novel avenues for connecting the dynamical state and evolutionary phase of galaxy clusters to their scaling relations.