| Full text | |
| Author(s): |
Spina, L.
;
Melendez, J.
;
Karakas, A. I.
;
Ramirez, I.
;
Monroe, T. R.
;
Asplund, M.
;
Yong, D.
Total Authors: 7
|
| Document type: | Journal article |
| Source: | Astronomy & Astrophysics; v. 593, SEP 2016. |
| Web of Science Citations: | 30 |
| Abstract | |
Context. The chemical composition of stars is intimately linked to the formation and evolution of the Galaxy. Aims. We aim to trace the chemical evolution of the Galactic disk through the inspection of the {[}X/Fe]-age relations of 24 species from C to Eu. Methods. Using high-resolution and high signal-to-noise UVES spectra of nine solar twins, we obtained precise estimates of stellar ages and chemical abundances. These determinations have been integrated with additional accurate age and abundance determinations from recent spectroscopic studies of solar twins existing in the literature, comprising superb abundances with 0.01 dex precision. Based on this data set, we outlined the {[}X/Fe]-age relations over a time interval of 10 Gyr. Results. We present the {[}X/Fe] -age relations for 24 elements (C, O, Na, Mg, Al, Si, S, K, Ca, Sc, Ti, V, Cr, Mn, Co, Ni, Cu, Zn, Y, Ba, La, Ce, Nd, and Eu). Each different class of elements showed a distinct evolution with time that relies on the different characteristics, rates, and timescales of the nucleosynthesis sites from which they are produced. The alpha-elements are characterized by a {[}X/Fe] decrease with time. Strikingly, the opposite behavior is observed for Ca. The iron-peak elements show an early {[}X /Fe] increase followed by a decrease towards the youngest stars. The {[}X /Fe] for the n-capture elements decrease with age. We also found that both {[}Mg/Y] and {[}Al/Y] are precise stellar clocks, with {[}Al/Y] showing the steepest dependence on age. Conclusions. Knowledge of the {[}X /Fe]-age relations is a gold mine from which we can achieve a great understanding of the processes that governed the formation and evolution of the Milky Way. Through the reverse engineering of these relations we will be able to put strong constraints on the nature of the stellar formation history, the SNe rates, the stellar yields, and the variety of the SNe progenitors. (AU) | |
| FAPESP's process: | 12/24392-2 - High precision spectroscopy: impact in the study of planets, stars, the galaxy and cosmology |
| Grantee: | Jorge Luis Melendez Moreno |
| Support Opportunities: | Research Projects - Thematic Grants |
| FAPESP's process: | 14/15706-9 - Differential abundances in solar-type stars: implications for planets formation and stellar nucleosynthesis |
| Grantee: | Lorenzo Spina |
| Support Opportunities: | Scholarships in Brazil - Post-Doctoral |