A critical assessment of the metal content of the intracluster medium

Abstract

Aims: Our goal is to provide a robust estimate of the metal content of the intracluster medium (ICM) in massive clusters. Methods: We made use of published abundance profiles for a sample of ~60 nearby systems. We included in our estimate uncertainties associated with the measurement process and with the almost total lack of information in cluster outskirts. Results: We performed a first, albeit rough, census of metals and find that the mean abundance of the ICM within r180 is very poorly constrained, 0.06 Z☉ ≲ Z ≲ 0.26 Z☉ and presents no disagreement with expectations. Similarly, whether and how the bulk of the metal content in clusters varies with cosmic time are very much open questions. Conclusions: A solid estimate of abundances in cluster outskirts could be achieved by combining observations of the two experiments that will operate on board Athena, the XIFU and the WFI, provided they do not fall victim to the de-scoping process that has afflicted several space observatories over the last decade.