Chemical Abundances of Main-sequence, Turnoff, Subgiant, and Red Giant Stars from APOGEE Spectra. II. Atomic Diffusion in M67 Stars

Souto D.; Prieto C.A.; Cunha K.; Pinsonneault M.; Smith V.V.; Garcia-Dias R.; Bovy J.; Garcia-Hernández D.A.; Holtzman J.; Johnson J.A.; Jönsson H.; Majewski, S. R.; Shetrone M.; Sobeck J.; Zamora O.; et. al.

Abstract

Chemical abundances for 15 elements (C, N, O, Na, Mg, Al, Si, K, Ca, Ti, V, Cr, Mn, Fe, and Ni) are presented for 83 stellar members of the 4 Gyr old solar-metallicity open cluster M67. The sample contains stars spanning a wide range of evolutionary phases, from G dwarfs to red clump stars. The abundances were derived from near-IR (lambda 1.5-1.7 mu m) high-resolution spectra (R = 22,500) from the SDSS-IV/Apache Point Observatory Galactic Evolution Experiment (APOGEE) survey. A 1D local thermodynamic equilibrium abundance analysis was carried out using the APOGEE synthetic spectral libraries, via chi(2) minimization of the synthetic and observed spectra with the qASPCAP code. We found significant abundance differences (similar to 0.05-0.30 dex) between the M67 member stars as a function of the stellar mass (or position on the Hertzsprung-Russell diagram), where the abundance patterns exhibit a general depletion (in [X/H]) in stars at the main-sequence turnoff. The amount of the depletion is different for different elements. We find that atomic diffusion models provide, in general, good agreement with the abundance trends for most chemical species, supporting recent studies indicating that measurable atomic diffusion operates in M67 stars.

Más información

Título según WOS: Chemical Abundances of Main-sequence, Turnoff, Subgiant, and Red Giant Stars from APOGEE Spectra. II. Atomic Diffusion in M67 Stars
Título según SCOPUS: Chemical Abundances of Main-sequence, Turnoff, Subgiant, and Red Giant Stars from APOGEE Spectra. II. Atomic Diffusion in M67 Stars
Título de la Revista: ASTROPHYSICAL JOURNAL
Volumen: 874
Número: 1
Editorial: IOP PUBLISHING LTD
Fecha de publicación: 2019
Idioma: English
DOI:

10.3847/1538-4357/ab0b43

Notas: ISI, SCOPUS