The temporal evolution of neutron-capture elements in the Galactic discs
dc.contributor.author | Spina, Lorenzo | pt_BR |
dc.contributor.author | Meléndez, Jorge | pt_BR |
dc.contributor.author | Karakas, Amanda I. | pt_BR |
dc.contributor.author | Santos, Leonardo Augusto Gonçalves dos | pt_BR |
dc.contributor.author | Bedell, Megan | pt_BR |
dc.contributor.author | Asplund, Martin | pt_BR |
dc.contributor.author | Ramírez, Iván | pt_BR |
dc.contributor.author | Yong, David | pt_BR |
dc.contributor.author | Alves-Brito, Alan | pt_BR |
dc.contributor.author | Bean, Jacob L. | pt_BR |
dc.contributor.author | Dreizler, Stefan | pt_BR |
dc.date.accessioned | 2018-06-21T02:32:40Z | pt_BR |
dc.date.issued | 2018 | pt_BR |
dc.identifier.issn | 0035-8711 | pt_BR |
dc.identifier.uri | http://hdl.handle.net/10183/179618 | pt_BR |
dc.description.abstract | Important insights into the formation and evolution of the Galactic disc(s) are contained in the chemical compositions of stars.We analysed high-resolution and high signal-to-noise HARPS spectra of 79 solar twin stars in order to obtain precise determinations of their atmospheric parameters, ages (σ ∼0.4 Gyr) and chemical abundances (σ <0.01 dex) of 12 neutron-capture elements (Sr, Y, Zr, Ba, La, Ce, Pr, Nd, Sm, Eu, Gd and Dy). This valuable data set allows us to study the [X/Fe]-age relations over a time interval of ∼10 Gyr and among stars belonging to the thin and thick discs. These relations show that (i) the s-process has been the main channel of nucleosynthesis of n-capture elements during the evolution of the thin disc; (ii) the thick disc is rich in r-process elements which suggests that its formation has been rapid and intensive. In addition, the heavy (Ba, La, Ce) and light (Sr, Y, Zr) s-process elements revealed details on the dependence between the yields of AGB stars and the stellar mass or metallicity. Finally, we confirmed that both [Y/Mg] and [Y/Al] ratios can be employed as stellar clocks, allowing ages of solar twin stars to be estimated with an average precision of ∼0.5 Gyr. | en |
dc.format.mimetype | application/pdf | pt_BR |
dc.language.iso | eng | pt_BR |
dc.relation.ispartof | Monthly notices of the royal astronomical society. Oxford. Vol. 474, no. 2 (Feb. 2018), p. 2580-2593 | pt_BR |
dc.rights | Open Access | en |
dc.subject | Evolucao galatica | pt_BR |
dc.subject | Stars: abundances | en |
dc.subject | Composicao estelar | pt_BR |
dc.subject | Galaxy: abundances | en |
dc.subject | Galaxy: disc | en |
dc.subject | Populacoes estelares | pt_BR |
dc.subject | Galaxy: evolution | en |
dc.title | The temporal evolution of neutron-capture elements in the Galactic discs | pt_BR |
dc.type | Artigo de periódico | pt_BR |
dc.identifier.nrb | 001065343 | pt_BR |
dc.type.origin | Estrangeiro | pt_BR |
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