The Structure of the Galactic Halo
Abstract
An analysis of the space distribution of metal-poor RR Lyrae stars from recent surveys suggests that Galactic halo can be described in terms of a flattened inner component, which is dominant at the sun's position, and a spherical outer component. The model is consistent with faint star counts if the local disk to halo star density ratio is about 150:1. The space distribution of metal-poor globular clusters is also consistent with the model. The similarity in Fe/H distributions between the inner and outer subsamples of globular clusters suggests that the dominant flattening mechanism is due to the dynamical evolution of an extant population of stars and clusters, rather than to a process involving gaseous dissipation and star formation with accompanying metal enrichment.
- Publication:
-
The Galaxy
- Pub Date:
- 1987
- Bibcode:
- 1987ASIC..207..281H
- Keywords:
-
- Galactic Structure;
- Halos;
- Milky Way Galaxy;
- Galactic Evolution;
- Globular Clusters;
- Metallicity;
- Statistical Analysis;
- Astrophysics