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| Paper: |
Abundance Determination of the Neutron-Capture Elements Y, Zr, La, and Ce in Open Clusters. |
| Volume: |
445, Why Galaxies Care about AGB Stars II: Shining Examples and Common Inhabitants |
| Page: |
159 |
| Authors: |
Maiorca, E.; Randich, S.; Busso, M.; Magrini, L.; Palmerini, S. |
| Abstract: |
We have derived abundances of four neutron-capture elements: yttrium,
zirconium, lanthanum, and cerium, in a large sample of dwarfs and RGB
stars that are members of Galactic open clusters. These stars have not
produced s-elements yet, and so the abundances we measured were
inherited from previous generations. We can trace the s-element
evolution from the formation of the Galactic disk up to a few million
years ago. Clusters younger than about 1.0 Gyr show an enrichment of
their mean s-element abundances. Chemical evolutionary models are
able to fit this growth only by assuming that low-mass AGB stars with
masses in the range of about 1.2–1.5 M☉ produce yields larger
than those predicted by the standard AGB nucleosynthesis. Therefore
new nucleosynthesis calculations are required for these stars, so that
chemical evolutionary models can fit the observed trends of the
s-elements. |
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