Forming at the nodes of the Cosmic Web and growing hierarchically via mass accretion, galaxy clusters are the largest virialized halos in our universe, composed of dark matter (DM; ≥85%), ionized... Show moreForming at the nodes of the Cosmic Web and growing hierarchically via mass accretion, galaxy clusters are the largest virialized halos in our universe, composed of dark matter (DM; ≥85%), ionized hot plasma in theintracluster medium (ICM; ≥10-15%), and galaxies (≥1-5%). The intracluster medium (ICM) consists of fully ionized plasma with temperatures of 10^7 - 10^8 K, emitting X-rays mostly via thermal bremsstrahlung. X-rayspectroscopic analysis enables us to probe physical properties of the ICM such as temperature, density, abundance and gas motions. Numerical simulations predict that cluster outskirts exhib. This thesis focuses on X-ray observations of the outskirts of galaxy clusters, especially dynamical features observed in X-ray and radio. This study mainly aims to push the sensitivity limit of X-ray observations, by exploring the most mysterious and exciting parts of the galaxy clusters out to the virial radius. Show less
Emonts, B.H.C.; Lehnert, M.D.; Lebowitz, S.; Miley, G.K.; Villar-Martín, M.; Norris, R.; ... ; Feain, I. 2023
The intracluster medium (ICM) is a hot, tenuous and X-ray emitting gas that pervades galaxy clusters. Meanwhile, extended synchrotron sources, i.e., radio relics and radio halos are frequently... Show moreThe intracluster medium (ICM) is a hot, tenuous and X-ray emitting gas that pervades galaxy clusters. Meanwhile, extended synchrotron sources, i.e., radio relics and radio halos are frequently observed in galaxy cluster, for which the two widely accepted particle acceleration are shock acceleration and turbulent acceleration, respectively. Both of these scenarios are due to ICM motions, which means that X-ray observations of the ICM are fundamental for quantifying shock wave and turbulence properties to test the acceleration models. This thesis focuses on X-ray observations of galaxy clusters, and covers topics from ICM shock - radio relic connection to turbulence - radio halo connection. The new observational evidences further support the two acceleration scenario. Show less
