Chemical enrichment: from stars to the intracluster medium

François Mernier – IRAP

Hot, X-ray emitting atmospheres permeating the large gravitational well of galaxy clusters are rich in heavy elements (N, O, Si, Fe, etc.). Following Carl Sagan’s famous quote « We are made of star-stuff », these metals must have been synthesised by stars and supernovae within stellar populations of cluster galaxies, before being ejected and mixed outside of their galactic haloes. As such large scales, metals constitute thus a fossil record of the chemical enrichment of the Universe. Measuring their abundances (as well as their spatial distribution) in the intracluster medium via X-ray spectroscopy therefore offers us the unique opportunity to understand: (i) what stars and supernovae are responsible of the bulk of the enrichment of the Universe; (ii) when in cosmic history and (iii) by which mechanisms this very large scale enrichment took place. 

In this seminar, we will first review key findings from the previous generation of X-ray missions (e.g. XMM-Newton, Suzaku). We will then see the first exciting results at unprecedentedly high, non-dispersive spectral resolution offered XRISM (launched very recently) and – last but not least, – we will discuss the remarkable promises of the revolutionary X-IFU instrument onboard the future large European X-ray mission NewAthena.