A critical assessment of the metal content of the ICM
  Our goal is to provide a robust estimate of the metal content of the ICM in
massive clusters. We make use of published abundance profiles for a sample of
~60 nearby systems, we include in our estimate uncertainties associated to the
measurement process and to the almost total lack of measures in cluster
outskirts. We perform a first, albeit rough, census of metals finding that the
mean abundance of the ICM within r_180 is very poorly constrained, 0.06Z_sol <
Z < 0.26Z_sol, and presents no tension with expectations. Similarly, the
question of if and how the bulk of the metal content in clusters varies with
cosmic time, is very much an open one. A solid estimate of abundances in
cluster outskirts could be achieved by combining observations of the two
experiments which 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.
