An XMM-Newton Spatially-Resolved Study of Metal Abundance Evolution in Distant Galaxy Clusters

Context. We present an XMM-Newton analysis of the X-ray spectra of 39 clusters of galaxies at 0.4 2�) abundance evolution with redshift. The most significant de viation from no evolution (at a 90% confidence level) is observed by consid ering the emission from the whole cluster (r < 0.6r500), which can be parametrized as Z ∝ (1 + z) −0.8±0.5 . Dividing the emission into three radial bins, no significan t evidence of abundance evolution is observed when fitting the data with a power law. We find close agreement with measurements presented in previous studies. Computing the error-weighted mean of the spatially resolved abundances into three redshift bins, we find that it is consi stent with being constant with redshift. Although the large error bars in the measurement of the weighted-mean abundance prevent us from claiming any statistically significant spatially resolved evolution, the trend with z in the 0.15-0.4r500 radial bin complements nicely the measures of Maughan et al., and broadly agrees with theoretical predictions. We also find that the data points derived from the spatially resolved analysis are well-fitted by the relation Z(r, z) = Z0(1 + (r/0.15r500) 2 ) −a ((1 + z)/1.6) − , where Z0 = 0.36± 0.03, a = 0.32± 0.07, and = 0.25± 0.57, which represents a significant negative trend of Z with radius and no significant evolution with redshift. Conclusions. We present the first attempt to determine the evolution of abu ndance at different positions in the clusters and with redshift. However, the sample size and the low-quality data statistics associated with most of the clusters studied pre vents us from drawing any statistically significant conclusion about the different evolutionary path that the different regions of t he clusters may have traversed.