| |
 |
| Paper: |
Standard Giant Branches in the Washington System: Calibration and Application to the Draco, Ursa Minor and Sextans Dwarf Spheroidal Galaxies |
| Volume: |
92, Formation of the Galactic Halo. . . . Inside and Out |
| Page: |
524 |
| Authors: |
Geisler, Doug; Sarajedini, Ata |
| Abstract: |
We investigate the use of the Washington system for obtaining accurate metallicities from the color of the giant branch, closely following the work of Da Costa & Armandroff (1990) using V,I photometry. T_1,(C-T_1) color-magnitude diagrams for 5 Galactic globular clusters are used as calibrators. The metallicity sensitivity of the (C-T_1)_0 color is found to be about 3 times higher than that of the corresponding V,I diagram. The method is then applied to three dwarf spheroidal galaxies in the outer halo. From our preliminary calibration, we find the mean metallicity to be -1.9 in Draco, -2.1 in Ursa Minor and -2.0 in Sextans, with a total error of ~ 0.1 dex. We also determine the intrinsic metallicity spreads to be ~ 0.2 dex in each galaxy. Our values are compared with other work, and are generally found to be in good agreement. |
|
|
|
|
|
