A uniform metallicity in the outskirts of massive, nearby galaxy
  clusters
  Suzaku measurements of a homogeneous metal distribution of $Z\sim0.3$ Solar
in the outskirts of the nearby Perseus cluster suggest that chemical elements
were deposited and mixed into the intergalactic medium before clusters formed,
likely over 10 billion years ago. A key prediction of this early enrichment
scenario is that the intracluster medium in all massive clusters should be
uniformly enriched to a similar level. Here, we confirm this prediction by
determining the iron abundances in the outskirts ($r>0.25r_{200}$) of a sample
of ten other nearby galaxy clusters observed with Suzaku for which robust
measurements based on the Fe-K lines can be made. Across our sample the iron
abundances are consistent with a constant value, $Z_{\rm Fe}=0.316\pm0.012$
Solar ($\chi^2=28.85$ for 25 degrees of freedom). This is remarkably similar to
the measurements for the Perseus cluster of $Z_{\rm Fe}=0.314\pm0.012$ Solar,
using the Solar abundance scale of Asplund et al. (2009).
