ERRATUM: “CHEMICAL INHOMOGENEITIES IN THE MILKY WAY STELLAR HALO” (2009, AJ, 137, 272)

Abstract

We have been alerted that the angular momentum components listed for Galactic globular clusters in Table 4 of our original analysis are at odds with other recent determinations of these quantities (e.g., Smith et al. 2009), and we thank Martin C. Smith for pointing out this discrepancy. We have identified and corrected an error in our computation of the cluster coordinates that affected both the angular momentum components and the orbital parameters listed in Table 4. In this Erratum, we present a corrected version of Table 4, revised Figures 16-19, which relied on the data presented in Table 4, and a very brief description of the observed correlations. This material supersedes that presented in Section 7.2 of the original analysis. Orbital parameters are included in all cases where the cluster completed enough orbits to allow these quantities to settle to a constant value. We also include kinematic properties of two clusters (M13 and NGC 104) that did not meet this criterion in our original analysis. Using the kinematic criteria for inner and outer halo membership listed in Section 4 of our original study, three clusters fit the inner halo classification (M4, M22, and M55), and six clusters fit the outer halo classification (M3, M13, M68, NGC 5466, Pal 5, and Pal 12). Figures 16-19 display mean abundance ratios for these clusters using the corrected orbital parameters. There may be a hint that [Mg/Fe] in the outer halo clusters ([Mg/Fe] = +0.20 ± 0.09, σ= 0.15, N= 4) is slightly lower than in the inner halo clusters ([Mg/Fe] = +0.35 ± 0.07, σ= 0.10, N= 3), even if we exclude Pal 12, which shares the same low [α/Fe] abundance ratios as Sagittarius. The mean dispersions in [X/Fe] of the inner and outer halo clusters are comparable. The [Ba/Eu] ratio in the outer halo clusters ([Ba/Eu] = –0.32 ± 0.07, σ= 0.12, N= 4) is also lower than in the inner halo clusters ([Ba/Eu] = +0.00 ± 0.20, σ= 0.28, N= 3), again excluding Pal 12. The [Y/Fe] ratio may correlate with cluster orbital parameters in that only sub-solar [Y/Fe] ratios are found in clusters with R apo 10 kpc, |Z max| 5 kpc, or V 100 km s-1. These trends generally resemble those observed in metal-poor field stars. We stress that this error only affects the globular cluster kinematic properties discussed in Section 7.2 of the original analysis. All other sections of that work, including the kinematic properties for field halo stars listed in Table 1, are correct in the original version.