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Paper: |
The AGB Population of NGC 6822 |
Volume: |
445, Why Galaxies Care about AGB Stars II: Shining Examples and Common Inhabitants |
Page: |
409 |
Authors: |
Sibbons, L. F.; Cioni, M.-R. L.; Irwin, M.; Rejkuba, M. |
Abstract: |
The metallicity gradient and the stellar distribution within the Local
Group dwarf galaxy NGC 6822 has been studied photometrically
using asymptotic branch (AGB) stars. In order to study the stellar and
metallicity distributions, the carbon- and oxygen-rich AGB
stars have been isolated using deep high-quality near-infrared UKIRT
photometry. The ratio between them, the C/M ratio, has been used to
derive the [Fe/H] abundance within the galaxy. The [Fe/H] abundance
and stellar distribution were analysed as a function of galactic radius.
A mean C/M ratio of 0.288±0.014 has been found, which corresponds
to an iron abundance of [Fe/H] = –1.14±0.08 dex, with variations
in the north and south as well as at larger galactocentric distances.
Variations in the magnitude of the tip of the red giant branch have
also been detected. |
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