Chemical analysis of three barium stars: HD 51959, HD 88035, HD 121447

TL;DR

This study provides detailed elemental abundance analyses of three nitrogen-enhanced barium stars using high-resolution spectra, revealing their chemical compositions, metallicities, and kinematic memberships, with first-time results for two stars and a comprehensive reanalysis of the third.

Contribution

First detailed high-resolution chemical abundance analysis of three nitrogen-enhanced barium stars, including new results for HD 51959 and HD 88035 and a comprehensive reanalysis of HD 121447.

Findings

HD 51959 and HD 88035 have near-solar metallicity with neutron-capture element enhancement.

HD 121447 is moderately metal-poor with significant carbon and neutron-capture element enhancement.

All three stars are members of the thin disk population based on kinematic analysis.

Abstract

We present elemental abundance results from high resolution spectral analysis of three nitrogen-enhanced barium stars. The analysis is based on spectra obtained with the FEROS attached to 1.52m telescope at ESO, Chile. The spectral resolution is R~48000 and the spectral coverage spans from 3500-9000\AA\,. For the objects HD 51959 and HD 88035, we present the first time abundance analyses results. Although a few studies are available in literature on the object HD 121447, the results are significantly different from each other. We have therefore carried out a detailed chemical composition study for this object based on a high resolution spectrum with high S/N ratio, for a better understanding of the origin of the abundance patterns observed in this star. Stellar atmospheric parameters, the effective temperature, surface gravity, microturbulence and metallicity of the stars are determined from the LTE analysis using model atmospheres. The metallicity of HD 51959 and HD 88035 are found to be near-solar; they exhibit enhanced abundances of neutron-capture elements. HD 121447 is found to be moderately metal-poor with [Fe/H]=-0.65. While carbon is near-solar in the other two objects, HD 121447 shows carbon enhancement at a level, [C/Fe]=0.82. Neutron-capture elements are highly enhanced with [X/Fe]>2 (X: Ba, La, Pr, Nd, Sm) in this object. The alpha- and iron-peak elements show abundances very similar to field giants with the same metallicity. From kinematic analysis all the three objects are found to be members of thin disk population with a high probability of 0.99, 0.99 and 0.92 for HD 51959, HD 88035 and HD 121447 respectively.