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(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.)

Planet signatures and effect of the chemical evolution of the Galactic thin-disk stars

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Autor(es):
Spina, Lorenzo [1] ; Melendez, Jorge [1] ; Ramirez, Ivan [2]
Número total de Autores: 3
Afiliação do(s) autor(es):
[1] Univ Sao Paulo, IAG, Dept Astron, Rua Matao 1226, BR-05509900 Sao Paulo, SP - Brazil
[2] Univ Texas Austin, Dept Astron, 2515 Speedway, Stop C1400, Austin, TX 78712 - USA
Número total de Afiliações: 2
Tipo de documento: Artigo Científico
Fonte: Astronomy & Astrophysics; v. 585, JAN 2016.
Citações Web of Science: 30
Resumo

Context. Studies based on high-precision abundance determinations revealed that chemical patterns of solar twins are characterised by the correlation between the differential abundances relative to the Sun and the condensation temperatures (T-c) of the elements. It has been suggested that the origin of this relation is related to the chemical evolution of the Galactic disk, but other processes, associated with the presence of planets around stars, might also be involved. Aims. We analyse HIRES spectra of 14 solar twins and the Sun to provide new insights on the mechanisms that can determine the relation between {[}X/H] and T-c. Methods. Our spectroscopic analysis produced stellar parameters (T-eff, log g, {[}Fe/H], and xi), ages, masses, and abundances of 22 elements (C, O, Na, Mg, Al, Si, S, K, Ca, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Sr, Y, and Ba). We used these determinations to place new constraints on the chemical evolution of the Galactic disk and to verify whether this process alone can explain the different {[}X/H]-T-c slopes observed so far. Results. We confirm that the {[}X/Fe] ratios of all the species correlate with age. The slopes of these relations allow us to describe the effect that the chemical evolution of the Galactic disk has on the chemical patterns of the solar twins. After subtracting the chemical evolution effect, we find that the unevolved {[}X/H]-T-c slope values do not depend on the stellar ages anymore. However, the wide diversity among these {[}X/H]-T-c slopes, covering a range of +/- 4 x 10(-5) dex K-1, indicates that processes in addition to the chemical evolution may affect the {[}X/H]-T-c slopes. Conclusions. The wide range of unevolved {[}X/H]-T-c slope values spanned at all ages by our sample could reflect the wide diversity among exo-planetary systems observed so far and the variety of fates that the matter in circumstellar disks can experience. (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