The metal abundance range in the Ursa Minor dwarf galaxy
Abstract
Observations, made with the Hale 5 m telescope multichannel scanner and digital spectrograph, of a sample of red giants in the Ursa Minor dwarf spheroidal galaxy (1) confirm the large width of the giant branch in the color-magnitude diagram and (2) indicate that it is caused by a metal abundance range of about 1 dex. Similar metal abundance ranges are found for Ursa Minor and the Draco dwarf spheroidal. Observations are compared with elliptical galaxy chemical evolution models including mass loss, and while the models are found to be consistent with the metal abundance dispersions found in the dwarf spheroidals, they are inconsistent with the lack of detectable dispersions in globular clusters comparable in mass to Ursa Minor and Draco, such as M92. Attention is also given to the spectrophotometry of the peculiar star, K, discovered by Canterna and Schommer (1978).
- Publication:
-
The Astrophysical Journal
- Pub Date:
- December 1981
- DOI:
- 10.1086/159440
- Bibcode:
- 1981ApJ...251...52Z
- Keywords:
-
- Abundance;
- Galactic Structure;
- Metals;
- Red Giant Stars;
- Stellar Spectrophotometry;
- Chemical Evolution;
- Color-Magnitude Diagram;
- Elliptical Galaxies;
- Globular Clusters;
- Late Stars;
- Telescopes;
- Astronomy