Iron in X-COP: Tracing enrichment in cluster outskirts with high accuracy abundance profiles

We present the first metal abundance profiles for a representative sample ofmassive clusters. Our measures extend to $R_{500}$ and are corrected for asystematic error plaguing previous outskirt estimates. Our profiles flatten outat large radii, admittedly not a new result, however the radial range andrepresentative nature of our sample extends its import well beyond previousfindings. We find no evidence of segregation between cool-core andnon-cool-core systems beyond $\sim 0.3 R_{500}$, implying that, as was foundfor thermodynamic properties (Ghirardini et al, 2019), the physical state ofthe core does not affect global cluster properties. Our mean abundance within$R_{500}$ shows a very modest scatter, $< $15%, suggesting the enrichmentprocess must be quite similar in all these massive systems. This is a newfinding and has significant implications on feedback processes. Together withresults from thermodynamic properties presented in a previous X-COP paper, itaffords a coherent picture where feedback effects do not vary significantlyfrom one system to another. By combing ICM with stellar measurements we havefound the amount of Fe diffused in the ICM to be about ten times higher thanthat locked in stars. Although our estimates suggest, with some strength, thatthe measured iron mass in clusters is well in excess of the predicted one,systematic errors prevent us from making a definitive statement. Furtheradvancements will only be possible when systematic uncertainties, principallythose associated to stellar masses, both within and beyond $R_{500}$, can bereduced.