A uniform metallicity in the outskirts of massive, nearby galaxy clusters
Autoři
URBAN, Ondrej (703 Slovensko), Norbert WERNER (703 Slovensko, garant, domácí), S. W. ALLEN (826 Velká Británie a Severní Irsko), A. SIMIONESCU (642 Rumunsko) a A. MANTZ (840 Spojené státy)
Vydání
Monthly Notices of the Royal Astronomical Society, Oxford, OXFORD UNIV PRESS, 2017, 0035-8711
Suzaku measurements of a homogeneous metal distribution of Z similar to 0.3 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 10 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(Fe) = 0.316 +/- 0.012 Solar (chi(2) = 28.85 for 25 degrees of freedom). This is remarkably similar to the measurements for the Perseus cluster of Z(Fe) = 0.314 +/- 0.012 Solar, using the Solar abundance scale of Asplund et al.