  The hot intra-cluster medium (ICM) permeating galaxy clusters and groups is
not pristine, as it is continuously enriched by metals synthesised in Type Ia
(SNIa) and core-collapse (SNcc) supernovae since the major epoch of star
formation (z ~ 2-3). The cluster/group enrichment history and the mechanisms
responsible for releasing and mixing the metals can be probed via the radial
distribution of SNIa and SNcc products within the ICM. In this paper, we use
deep XMM-Newton/EPIC observations from a sample of 44 nearby cool-core galaxy
clusters, groups, and ellipticals (CHEERS) to constrain the average radial O,
Mg, Si, S, Ar, Ca, Fe, and Ni abundance profiles. The radial distributions of
all these elements, averaged over a large sample for the first time, represent
the best constrained profiles available currently. We find an overall decrease
of the Fe abundance with radius out to ~$0.9 r_{500}$ and ~$0.6 r_{500}$ for
clusters and groups, respectively, in good agreement with predictions from the
most recent hydrodynamical simulations. The average radial profiles of all the
other elements (X) are also centrally peaked and, when rescaled to their
average central X/Fe ratios, follow well the Fe profile out to at least
~0.5$r_{500}$. Using two sets of SNIa and SNcc yield models reproducing well
the X/Fe abundance pattern in the core, we find that, as predicted by recent
simulations, the relative contribution of SNIa (SNcc) to the total ICM
enrichment is consistent with being uniform at all radii, both for clusters and
groups. In addition to implying that the central metal peak is balanced between
SNIa and SNcc, our results suggest that the enriching SNIa and SNcc products
must share the same origin, and that the delay between the bulk of the SNIa and
SNcc explosions must be shorter than the timescale necessary to diffuse out the
metals.
