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Detailed Chemical Evolution of Carina and Sagittarius Dwarf Spheroidal Galaxies
| Content Provider | Semantic Scholar |
|---|---|
| Author | Lanfranchi, Gustavo A. Matteucci, Francesca Cescutti, Gabriele Matão, R. Do |
| Copyright Year | 2006 |
| Abstract | Aims. In order to verify the e ffects of the most recent data on the evolution of Carina and Sag ittarius Dwarf Spheroidal Galaxies (dSph) and to set tight constraints on the main parameters of chemical evo lution models, we study in detail the chemical evolution of t hese galaxies through comparisons between the new data and the predictions of a mod el, already tested to reproduce the main observational cons trai ts in dSphs. Methods. Several abundance ratios, such as [ α/Fe], [Ba/Fe] and [Eu/Fe], and the metallicity distribution of stars are compared to the predictions of our models adopting the observationally der ived star formation histories in these galaxies. Results. These new comparisons confirm our previously suggested scen ario for the evolution of these galaxies, and allow us to bett er fix the star formation and wind parameters. In particular, fo Carina our predictions indicates that the best e fficiency of star formation is ν = 0.15 Gyr−1, that the best wind e fficiency parameter is wi = 5 (the wind rate is five times stronger than the star formation rate), and that the star formation history, which produces the best fit to the observed metallicity distribution of stars is characteriz d by several episodes of activity. In the case of Sagittarius our results suggest tha t ν = 3 Gyr−1 andwi = 9, again in agreement with our previous work. Finally, we show new predictions for [N /Fe] and [C/Fe] ratios for the two galaxies suggesting a scenario for Sag ittarius very similar to the one of the solar vicinity in the Milky Way, except for a slight decrease of [N /Fe] ratio at high metallicities due to the galactic wind. For Carina we predict a larger [N/Fe] ratio at low metallicities, reflecting the lower star for mation efficiency of this galaxy relative to Sagittarius and the Milky W ay. |
| File Format | PDF HTM / HTML |
| Alternate Webpage(s) | http://arxiv.org/pdf/astro-ph/0603577v1.pdf |
| Alternate Webpage(s) | http://cds.cern.ch/record/936773/files/0603577.pdf |
| Language | English |
| Access Restriction | Open |
| Subject Keyword | Bett Biological Evolution Compaq Evo Curve fitting DWARF Ehrlich units per deciliter Field electron emission GUCY2C protein, human Galaxy Iron Large Music Player Daemon Population Parameter Stars, Celestial Structure of carina Tacrine newton |
| Content Type | Text |
| Resource Type | Article |
