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| Paper: |
DDO Metallicities for Field and Cluster Giants |
| Volume: |
92, Formation of the Galactic Halo. . . . Inside and Out |
| Page: |
71 |
| Authors: |
Anthony-Twarog, Barbara J.; Twarog, Bruce A. |
| Abstract: |
We refer to an expanded sample of stars with high dispersion spectroscopic abundances (McWilliam 1990) and DDO photometry to explore a suggested discrepancy in the DDO-metallicity scale for giants with old disk and halo metallicities. It is demonstrated that the DDO isometallicity relations, which were based on globular cluster giant data, differ in slope and zero-point from the relation defined by the field giants. The cluster stars at intermediate metallicity exhibit systematically higher CN strengths than do the field stars at the same [Fe/H]. At the metal-rich end, the isometallicity relation for 47 Tuc giants reveals a slope which differs from the field stars in the same manner as found for the intermediate-metallicity clusters; it is additionally evident that the hotter field stars with [Fe/H]spec between --0.35 and --0.55 occupy the same region of the C_0(3845),C_0(4548) diagram as 47 Tuc. |
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