X-Raying the hot gas in the outskirts of galaxy clusters

Zhu, Z. (2024)

Doctoral Thesis

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 hot plasma in the
intracluster 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-ray
spectroscopic 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.

• Galaxy clusters
• Intracluster medium
• Non-thermal radiation sources
• Large scale structure of the universe
• X-ray astronomy

• All authors: Zhu, Z.
• Supervisor: Kaastra, J.S.
• Co-supervisor: Simionescu, A.
• Committee: Snellen, I.A.G.; Röttgering, H.J.A.; Hoekstra, H.; Kuijken, K.H.; Vink, J.; Zhuravleva, I.
• Qualification: Doctor (dr.)
• Awarding Institution: Leiden Observatory, Faculty of Science, Leiden University
• Date: 2024-10-30