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The chemical evolution of Barium and Europium in the Milky
| Content Provider | Semantic Scholar |
|---|---|
| Author | Cescutti, G. François, Patrick Matteucci, Francesca Cayrel, Roger Spite, Monique |
| Copyright Year | 2005 |
| Abstract | Aims. We compute the evolution of the abundances of barium and euro pium in the Milky Way and we compare our results with the obser ved abundances from the recent UVES Large Program ”First Stars” . Methods. We use a chemical evolution model which already reproduces t he majority of observational constraints. Results. We confirm that barium is a neutron capture element mainly pro duced in the low mass AGB stars during the thermal-pulsing ph ase by the13C neutron source, in a slow neutron capture process. However, in o der to reproduce the [Ba /Fe] vs. [Fe/H] as well as the Ba solar abundance, we suggest that Ba should be also produced as an rprocess element by massive stars in the range 10-30 M⊙. On the other hand, europium should be only an r-process element produced in the same range of masses (10-30 M⊙), at variance with previous suggestions indicating a smaller mass range for the Eu producers. As it is well known, there is a large spread in the [Ba /Fe] and [Eu/Fe] ratios at low metallicities, although smaller in the newest data. With ou r model we estimate for both elements (Ba and Eu) the ranges fo r the r-process yields from massive stars which better reproduce the trend o f the data. We find that with the same yields which are able to ex plain the observed trends, the large spread in the [Ba /Fe] and [Eu/Fe] ratios cannot be explained even in the context of an inhom ogeneous models for the chemical evolution of our Galaxy. We therefore derive the amount by wh ich the yields should be modified to fully account for the obse rved spread. We then discuss several possibilities to explain the size of the spread. We finally suggest that the production ratio of [B a/Eu] could be almost constant in the massive stars. |
| File Format | PDF HTM / HTML |
| Alternate Webpage(s) | http://cds.cern.ch/record/897036/files/0510496.pdf |
| Alternate Webpage(s) | http://arxiv.org/pdf/astro-ph/0510496v1.pdf |
| Language | English |
| Access Restriction | Open |
| Subject Keyword | Barium Coupling (computer programming) Curve fitting Dietary Iron Ehrlich units per deciliter Eighty Euro currency European Union Europium Field electron emission I/O Controller Hub Iron Neutrons Sample Variance Small Stars, Celestial Stellar (payment network) WH, Rat Strain |
| Content Type | Text |
| Resource Type | Article |
