Busca avançada
Ano de início
Entree
(Referência obtida automaticamente do Web of Science, por meio da informação sobre o financiamento pela FAPESP e o número do processo correspondente, incluída na publicação pelos autores.)

The temporal evolution of neutron-capture elements in the Galactic discs

Texto completo
Autor(es):
Mostrar menos -
Spina, Lorenzo [1, 2] ; Melendez, Jorge [1] ; Karakas, Amanda I. [2] ; dos Santos, Leonardo [1, 3] ; Bedell, Megan [4, 5] ; Asplund, Martin [6] ; Ramirez, Ivan [7] ; Yong, David [6] ; Alves-Brito, Alan [8] ; Bean, Jacob L. [4] ; Dreizler, Stefan [9]
Número total de Autores: 11
Afiliação do(s) autor(es):
[1] Univ Sao Paulo, IAG, Dept Astron, Rua Matao 1226, BR-05509900 Sao Paulo, SP - Brazil
[2] Monash Univ, Monash Ctr Astrophys, Sch Phys & Astron, Clayton, Vic 3800 - Australia
[3] Observat Univ Geneve, 51 Chemin Maillettes, CH-1290 Versoix - Switzerland
[4] Dept Astron & Astrophys, 5640 S Ellis Ave, Chicago, IL 60637 - USA
[5] Flatiron Inst, Ctr Computat Astrophys, 162 5th Ave, New York, NY 10010 - USA
[6] Australian Natl Univ, Res Sch Astron & Astrophys, Cotter Rd, Canberra, ACT 2611 - Australia
[7] Tacoma Community Coll, 6501 South 19th St, Tacoma, WA 98466 - USA
[8] Univ Fed Rio Grande do Sul, Inst Fis, Ave Bento Goncalves 9500, Porto Alegre, RS - Brazil
[9] Georg August Univ Gottingen, Inst Astrophys, Wilhelmspl 1, D-37073 Gottingen - Germany
Número total de Afiliações: 9
Tipo de documento: Artigo Científico
Fonte: Monthly Notices of the Royal Astronomical Society; v. 474, n. 2, p. 2580-2593, FEB 2018.
Citações Web of Science: 23
Resumo

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 (sigma similar to 0.4 Gyr) and chemical abundances (sigma < 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 similar to 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 similar to 0.5 Gyr. (AU)

Processo FAPESP: 14/15706-9 - Abundâncias diferenciais em estrelas de tipo solar: implicações sobre a formação de planetas e nucleossíntese estelar
Beneficiário:Lorenzo Spina
Linha de fomento: Bolsas no Brasil - Pós-Doutorado
Processo FAPESP: 12/24392-2 - Espectroscopia de alta precisão: impacto no estudo de planetas, estrelas, a galáxia e cosmologia
Beneficiário:Jorge Luis Melendez Moreno
Linha de fomento: Auxílio à Pesquisa - Temático