Speaker
Description
Groups and clusters of galaxies are pervaded with hot gas (several tens to hundreds of million K), which emits in X-rays (mostly via bremsstrahlung) and which has been routinely observed with the last generations of X-ray telescopes. Because this intracluster medium (ICM) accounts for 70-90% of clusters' total baryonic content, it constitutes a central component in the growth and assembly of the largest scale structures of our Universe.
Despite immense progress over the last 25 years, many questions on the physics, dynamics, and chemistry of the ICM remain unsolved. Among which: (i) Through which physical processes is the gas heated to X-ray temperatures during accretion and mergers? (ii) How does the gas "flow" in clusters and how does it impact cluster (and galaxy) evolution? (iii) What is (are) the mechanism(s) at play governing the fine-tuned balance between the ICM thermodynamics and feedback from the central supermassive black hole in relaxed systems? (iv) What is the chemical composition of the ICM and when/how was our Universe on its largest scales enriched with stellar end products?
This talk reviews our knowledge and recent progress on these questions, with a particular focus on observations made with high grasp (eROSITA) and high-resolution spectroscopy missions (XRISM).
