Carbon, isotopic ratio C-12/C-13, and nitrogen in solar twins: constraints for the chemical evolution of the local disc

Autor(es)

Botelho, R. B. ^[1] ; Milone, A. de C. ^[1] ; Melendez, J. ^[2] ; Alves-Brito, A. ^[3] ; Spina, L. ^{[4, 5]} ; Bean, J. L. ^[6]

Afiliação do(s) autor(es)

^[1] Inst Nacl Pesquisas Espaciais, Div Astrofis, Av Astronautas 1758, BR-12227010 Sao Jose Dos Campos, SP - Brazil

^[2] Univ Sao Paulo, IAG, Dept Astron, Rua Matao 1226, BR-05509900 Sao Paulo, SP - Brazil

^[3] Univ Fed Rio Grande do Sul, Inst Fis, Av Bento Goncalves 9500, BR-91501970 Porto Alegre, RS - Brazil

^[4] Monash Univ, Sch Phys & Astron, Monash Ctr Astrophys, Clayton, Vic 3800 - Australia

^[5] ARC Ctr Excellence All Sky Astrophys 3 Dimens AST, Clayton, Vic - Australia

^[6] Univ Chicago, Dept Astron & Astrophys, 5640 S Ellis Ave, Chicago, IL 60637 - USA

• Tipo de documento: Artigo Científico
• Fonte: Monthly Notices of the Royal Astronomical Society; v. 499, n. 2, p. 2196-2213, DEC 2020.
• Citações Web of Science: 0

Resumo

Abundances of light elements in dwarf stars of different ages are important constraints for stellar yields, Galactic chemical evolution and exoplanet chemical composition studies. We have measured C and N abundances and C-12/C-13 ratios for a sample of 63 solar twins spanning a wide range in age, based on spectral synthesis of a comprehensive list of CHA-X and CNB-X features using HARPS spectra. The analysis of 55 thin disc solar twins confirms the dependences of {[}C/Fe] and {[}N/Fe] on {[}Fe/H]. {[}N/Fe] is investigated as a function of {[}Fe/H] and age for the first time for these stars. Our derived correlation {[}C/Fe]-age agrees with works for solar-type stars and solar twins, but the {[}N/Fe]-age correlation does not. The relations {[}C,N/Fe]-{[}Fe/H] and {[}C,N/Fe]-age for the solar twins lay under solar. C-12/C-13 is found correlated with {[}Fe/H] and seems to have decreased along the evolution of the local thin disc. Predictions from chemical evolution models for the solar vicinity corroborate the relations {[}C,N/Fe]-{[}Fe/H], C-12/C-13-age, and {[}N/O]-{[}O/H], but do not for the C-12/C-13-{[}Fe/H] and {[}C/O]-{[}O/H] relations. The N/O ratio in the Sun is placed at the high end of the homogeneous distribution of solar twins, which suggests uniformity in the N-O budget for the formation of icy planetesimals, watery superearths, and giant planets. C and N had different nucleosynthetic origins along the thin disc evolution, as shown by the relations of {[}C/N], {[}C/O], and {[}N/O] against {[}O/H] and age. {[}C/N] and {[}C/O] are particularly observed increasing in time for solar twins younger than the Sun. (AU)

• Processo FAPESP: 18/04055-8 - Espectroscopia de alta precisão: das primeiras estrelas aos planetas
• Beneficiário: Jorge Luis Melendez Moreno
• Modalidade de apoio: Auxílio à Pesquisa - Temático