Distributions of metallicity and abundance ratios

Distributions of metallicity [M/H] and abundance ratios [α/Fe] for each of the clusters derived from the line indices. Under the assumption of passive evolution there should not be any significant differences from cluster to cluster. Instead we find that MS0451.6-0305 has [M/H] about 0.2 dex below that of the other clusters, while RXJ0152.7-1237 has [α/Fe] about 0.3 dex above that of the other clusters.