Astronomy and Astrophysics – Astrophysics
Scientific paper
2003-04-17
Astronomy and Astrophysics
Astrophysics
16 pages, 5 figures, accepted for publication in PASA (Publications of the Astronomical Society of Australia)
Scientific paper
10.1071/AS02047
The chemical evolution of the Milky Way is investigated using a dual-phase metal-enriched infall model in which primordial gas fuels the earliest epoch of star formation, followed by the ongoing formation of stars from newly accreted gas. The latest metallicity distribution of local K-dwarfs is reproduced by this model, which allows the Galactic thin disk to form from slightly metal-enriched gas with alpha-element enhancement. Our model predicts ages for the stellar halo and thin disk of 12.5 and 7.4 Gyr, respectively, in agreement with empirically determined values. The model presented in this paper is compared with a similar dual-phase infall model from Chiappini et al. (2001). We discuss a degeneracy that enables both models to recover the K-dwarf metallicity distribution while yielding different star formation histories. The metallicity distribution function (MDF) of K-dwarfs is proposed to be more directly comparable to chemical evolution model results than the G-dwarf distribution because lower mass K-dwarfs are less susceptible to stellar evolutionary effects. The K-dwarf MDF should consequently be a better probe of star formation history and provide a stronger constraint to chemical evolution models than the widely used G-dwarf MDF. The corrections that should be applied to a G-dwarf MDF are quantified for the case of the outer halo of NGC 5128.
Fenner Yeshe
Gibson Brad K.
No associations
LandOfFree
Deriving the Metallicity Distribution Function of Galactic Systems does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Deriving the Metallicity Distribution Function of Galactic Systems, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Deriving the Metallicity Distribution Function of Galactic Systems will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-9930