Characterizing the companion AGBs using surface chemical composition of barium stars

Abstract

Barium stars are one of the important probes to understand the origin and evolution of slow neutron-capture process elements in the Galaxy. These are extrinsic stars, where the observed s-process element abundances are believed to have an origin in the now invisible companions that produced these elements at their Asymptotic Giant Branch phase of evolution. We have attempted to understand the s-process nucleosynthesis, as well as the physical properties of the companion stars through a detailed comparison of observed elemental abundances of 10 barium stars with the predictions from AGB nucleosynthesis models, FRUITY. For these stars, we have presented estimates of abundances of several elements, C, N, O, Na, Al, $\alpha$-elements, Fe-peak elements and neutron-capture elements Rb, Sr, Y, Zr, Ba, La, Ce, Pr, Nd, Sm and Eu. The abundance estimates are based on high resolution spectral analysis. Observations of Rb in four of these stars have allowed us to put a limit to the mass of the companion AGB stars. Our analysis clearly shows that the former companions responsible for the surface abundance peculiarities of these stars are low-mass AGB stars. Kinematic analysis have shown the stars to be members of Galactic disk population.

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Cited by in corpus (15)

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• Barium stars as tracers of s-process nucleosynthesis in AGB stars I. 28 stars with independently derived AGB mass
• Heavy elements in barium stars
• The formation of barium giants via mass accretion in binary systems
• HCT/HESP study of two carbon stars from the LAMOST survey
• Spectroscopic study of four metal-poor carbon stars from the Hamburg/ESO Survey: On confirming the low-mass nature of their companions
• Chemodynamical study of two CEMP-no stars from the Hamburg/ESO Survey
• Investigating three Sirius-like systems with SPHERE
• Spectroscopic study of Ba and CEMP-s stars: Mass distribution of AGB progenitors
• Probing the nucleosynthetic contribution of low-metallicity, low-mass star companions of CEMP stars
• High-resolution spectroscopic analysis of four new chemically peculiar stars
• Rubidium abundances of galactic disk stars
• Exploring giant barium stars: ${}^{12}\mathrm{C}{/}^{13}\mathrm{C}$ ratio and elemental abundances of carbon, nitrogen, and oxygen
• [Rb/Zr] ratio in Ba stars as diagnostics of the companion AGB stellar mass
• Full abundance study of two newly discovered barium giants