Redshift evolution of the hot intracluster gas metallicity in the
  C-EAGLE cluster simulations
  The abundance and distribution of metals in galaxy clusters contains valuable
information about their chemical history and evolution. By looking at how
metallicity evolves with redshift, it is possible to constrain the different
metal production channels. We use the C-EAGLE clusters, a sample of 30 high
resolution ($m_{gas} \simeq 1.8\times 10^{6}$ M$_{\odot}$) cluster zoom
simulations, to investigate the redshift evolution of metallicity, with
particular focus on the cluster outskirts. The early enrichment model, in which
the majority of metals are produced in the core of cluster progenitors at high
redshift, suggests that metals in cluster outskirts have not significantly
evolved since $z=2$. With the C-EAGLE sample, we find reasonable agreement with
the early enrichment model as there is very little scatter in the metallicity
abundance at large radius across the whole sample, out to at least $z=2$. The
exception is Fe for which the radial dependence of metallicity was found to
evolve at low redshift as a result of being mainly produced by Type Ia
supernovae, which are more likely to be formed at later times than
core-collapse supernovae. We also found considerable redshift evolution of
metal abundances in the cores of the C-EAGLE clusters which has not been seen
in other simulations or observation based metallicity studies. Since we find
this evolution to be driven by accretion of low metallicity gas, it suggests
that the interaction between outflowing, AGN heated material and the
surrounding gas is important for determining the core abundances in clusters.
