2016ApJ...826..124M

We present the results of an X-ray spectral analysis of 153 galaxy clusters observed with the Chandra, XMM-Newton, and Suzaku space telescopes. These clusters, which span 0 z r R₅₀₀) ICM metallicity (dZ/dz=-0.06±0.04 Z_☉), with a mean value at z=0.6 of <Z>=0.23±0.01 Z_☉ and a scatter of σ_ Z_=0.08±0.01 Z_☉. These results imply that the emission-weighted metallicity has not changed by more than 40% since z=1 (at 95% confidence), consistent with the picture of an early (z > 1) enrichment. We find, in agreement with previous works, a significantly higher mean value for the metallicity in the centers of cool core clusters versus non-cool core clusters. We find weak evidence for evolution in the central metallicity of cool core clusters (dZ/dz=-0.21±0.11 Z_☉), which is sufficient to account for this enhanced central metallicity over the past ∼10 Gyr. We find no evidence for metallicity evolution outside of the core (dZ/dz=-0.03±0.06 Z_☉), and no significant difference in the core-excised metallicity between cool core and non-cool core clusters. This suggests that strong radio-mode active galactic nucleus feedback does not significantly alter the distribution of metals at r\gt 0.15{R}_{500} . Given the limitations of current-generation X-ray telescopes in constraining the ICM metallicity at z > 1, significant improvements on this work will likely require next-generation X-ray missions.