Metallicity spread and dispersion among P1 stars

We also derive metallicity dispersions ({sigma}_[M/H]_) for the P1 and P2 stars of each GC. In all but three GCs, we measure a significant correlation between the metallicity and the {Delta}_F275W,F814W_ pseudo-color of the P1 stars such that stars with larger {Delta_F275W,F814W_ have higher metallicities. We measure metallicity spreads that range from 0.03 to 0.24dex and correlate with the GC masses.

As for the intrinsic metallicity dispersions, when combining the P1 and P2 stars, we measure values ranging from 0.02 dex to 0.08dex that correlate very well with the GC masses. We compared the metallicity dispersion among the P1 and P2 stars and found that the P2 stars have metallicity dispersions that are smaller or equal to that of the P1 stars. We find that both the metallicity spreads of the P1 stars (from the {Delta_F275W,F814W_ spread in the chromosome maps) and the metallicity dispersions ({sigma_[M/H]_) correlate with the GC masses, as predicted by some theoretical self-enrichment models presented in the literature.