The metal abundance range in the Draco dwarf galaxy.
Abstract
The metal abundances of 23 red giants in the Draco dwarf spheroidal galaxy are investigated on the basis of multichannel-scanner measurements of the spectral flux densities in 22 bands over the wavelength range from 3240 to 7620 A. The membership of the sample stars in Draco is checked, and the abundance determinations for 21 probable members are related to the two giant branches in Baade and Swope's (1961) color-magnitude diagram. It is found that there appears to be a range in metal abundance of about a factor of 2.7 in Draco, that the mean metal abundance of Draco is somewhat larger than that of the globular cluster M92, and that there is a paucity of very metal-poor stars in comparison with a flat distribution over metal abundance. Implications of these results for interpretations of the system's color-magnitude diagram, variable-star population, and evolution are discussed.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- November 1978
- DOI:
- 10.1086/156544
- Bibcode:
- 1978ApJ...225..790Z
- Keywords:
-
- Abundance;
- Elliptical Galaxies;
- Metals;
- Red Giant Stars;
- Spectrophotometry;
- Color-Magnitude Diagram;
- Galactic Evolution;
- Globular Clusters;
- Hertzsprung-Russell Diagram;
- Hydrogen Atoms;
- Iron;
- Late Stars;
- Tables (Data);
- Variable Stars;
- Astrophysics;
- Dwarf Galaxies:Metal Abundances;
- Dwarf Galaxies:Red Giants;
- Dwarf Galaxies:Stellar Content;
- Metal Abundances:Red Giants