Intracluster Medium Abundance Mapping with LEM

An essential component of the cosmic cycle of metals is found in the hot, X-ray emitting gas pervading clusters of galaxies and the cosmic web. On paper, the (close to) collisional ionization equilibrium of the intergalactic medium (IGM) allows extraordinarily accurate measurements of its abundances - offering the potential of a thorough understanding of the chemical history and dynamics of our Universe, as well as the stellar physics and evolution on the largest scales. In practice, however, the limited spectral resolution (and/or grasp) of current X-ray missions restricts abundance studies to the core region of the brightest systems; leaving most of the IGM yet widely unexplored. Here we demonstrate how the Line Emission Mapper (LEM) mission concept - thanks to its unprecedented energy resolution (< 2 eV), its very large field of view (30’ x 30’) and its excellent effective area (1600 cm² at E=0.5 keV) - will provide pioneer abundance constraints (also of yet undetected elements) out to the faint, diffuse outskirts regions, hence unveiling key information on chemical enrichment at galactic and Mpc scales.