Chemical abundances of 20 barium stars from the OHP spectra

Fuente: arXiv
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Main Authors: Yang, Guochao, Zhao, Jingkun, Liang, Yanchun, Spite, Monique, Spite, Francois, Shi, Jianrong, Liu, Shuai, Liu, Nian, Cui, Wenyuan, Zhao, Gang
Format: Preprint
Published: 2024
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author Yang, Guochao
Zhao, Jingkun
Liang, Yanchun
Spite, Monique
Spite, Francois
Shi, Jianrong
Liu, Shuai
Liu, Nian
Cui, Wenyuan
Zhao, Gang
author_facet Yang, Guochao
Zhao, Jingkun
Liang, Yanchun
Spite, Monique
Spite, Francois
Shi, Jianrong
Liu, Shuai
Liu, Nian
Cui, Wenyuan
Zhao, Gang
contents Based on the high resolution and high signal-to-noise spectra, we derived the chemical abundances of 20 elements for 20 barium (Ba-) stars. For the first time, the detailed abundances of four sample stars, namely HD 92482, HD 150430, HD 151101 and HD 177304 have been analyzed. Additionally, Ba element abundance has been measured using high resolution spectra for the first time in six of the other 16 sample stars. Based on the [s/Fe] ratios, the Ba-unknown star HD 115927 can be classified as a strong Ba-star, while the Ba-likely star HD 160538 can be categorized into a mild Ba-star. Consequently, our sample comprises three strong and 17 mild Ba-stars. The light odd-Z metal elements and Fe-peak elements exhibit near-solar abundances. The [α/Fe] ratios demonstrate decreasing trends with increasing metallicity. Moreover, the abundances of n-capture elements show significant enhancements in different degrees. Using a threshold of the signed distances to the solar r-process abundance pattern ds = 0.6, we find that all of our sample stars are normal Ba-stars, indicating that the enhancements of s-process elements should be attributed to material transfer from their companions. We compare the observed n-capture patterns of sample stars with the FRUITY models, and estimate the mass of the Thermally-Pulsing Asymptotic Giant Branch stars that previously contaminated the Ba-stars. The models with low masses can successfully explain the observations. From a kinematic point of view, we note that most of our sample stars are linked with the thin disk, while HD 130255 may be associated with the thick disk.
format Preprint
id arxiv_https___arxiv_org_abs_2410_13177
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Chemical abundances of 20 barium stars from the OHP spectra
Yang, Guochao
Zhao, Jingkun
Liang, Yanchun
Spite, Monique
Spite, Francois
Shi, Jianrong
Liu, Shuai
Liu, Nian
Cui, Wenyuan
Zhao, Gang
Solar and Stellar Astrophysics
Astrophysics of Galaxies
Based on the high resolution and high signal-to-noise spectra, we derived the chemical abundances of 20 elements for 20 barium (Ba-) stars. For the first time, the detailed abundances of four sample stars, namely HD 92482, HD 150430, HD 151101 and HD 177304 have been analyzed. Additionally, Ba element abundance has been measured using high resolution spectra for the first time in six of the other 16 sample stars. Based on the [s/Fe] ratios, the Ba-unknown star HD 115927 can be classified as a strong Ba-star, while the Ba-likely star HD 160538 can be categorized into a mild Ba-star. Consequently, our sample comprises three strong and 17 mild Ba-stars. The light odd-Z metal elements and Fe-peak elements exhibit near-solar abundances. The [α/Fe] ratios demonstrate decreasing trends with increasing metallicity. Moreover, the abundances of n-capture elements show significant enhancements in different degrees. Using a threshold of the signed distances to the solar r-process abundance pattern ds = 0.6, we find that all of our sample stars are normal Ba-stars, indicating that the enhancements of s-process elements should be attributed to material transfer from their companions. We compare the observed n-capture patterns of sample stars with the FRUITY models, and estimate the mass of the Thermally-Pulsing Asymptotic Giant Branch stars that previously contaminated the Ba-stars. The models with low masses can successfully explain the observations. From a kinematic point of view, we note that most of our sample stars are linked with the thin disk, while HD 130255 may be associated with the thick disk.
title Chemical abundances of 20 barium stars from the OHP spectra
topic Solar and Stellar Astrophysics
Astrophysics of Galaxies
url https://arxiv.org/abs/2410.13177