Abundance analysis of s-process enhanced barium stars

作者：Mahanta Upakul; Karinkuzhi Drisya; Goswami Aruna; Duorah Kalpana

来源：Monthly Notices of the Royal Astronomical Society, 2016, 463(2): 1213-1223.

DOI：10.1093/mnras/stw1995

• stars: abundances
• stars: chemically peculiar
• stars: individual: HD 49641
• stars: individual: HD 58368
• stars: individual: HD 119650
• stars: individual: HD 191010

Detailed chemical composition studies of stars with enhanced abundances of neutron-capture elements can provide observational constraints for neutron-capture nucleosynthesis studies and clues for understanding their contribution to the Galactic chemical enrichment. We present abundance results from high-resolution spectral analyses of a sample of four chemically peculiar stars characterized by s-process enhancement. High-resolution spectra (R similar to 42 000) of these objects spanning a wavelength range from 4000 to 6800 angstrom are taken from the ELODIE archive. We have estimated the stellar atmospheric parameters, the effective temperature T-eff, the surface gravity log g and metallicity [Fe/H] from local thermodynamic equilibrium analysis using model atmospheres. We report estimates of elemental abundances for several neutron-capture elements, Sr, Y, Zr, Ba, La, Ce, Pr, Nd, Sm, Eu and Dy. While HD 49641 and HD 58368 show [Ba/Fe] >= 1.16, the other two objects HD 119650 and HD 191010 are found to be mild barium stars with [Ba/Fe] similar to 0.4. The derived abundances of the elements are interpreted on the basis of existing theories for understanding their origin and evolution.

• 出版日期2016-12-1