Spectroscopic Study of Ba and CEMP-s Stars: Mass Distribution of AGB Progenitors
We have performed detailed high-resolution spectroscopic analysis on seven metal-poor stars (BD+75 348, BD+09 3019, HD238020, HE0319–0215, HE0507–1653, HE0930–0018, HE1023–1504) and derived their atmospheric parameters T _eff , log g , [Fe/H], and microturbulent velocity ( ξ ). The metallicity range...
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| Format: | Article |
| Language: | English |
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IOP Publishing
2023-01-01
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| Series: | The Astronomical Journal |
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| Online Access: | https://doi.org/10.3847/1538-3881/aca971 |
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| author | Partha Pratim Goswami Aruna Goswami |
| author_facet | Partha Pratim Goswami Aruna Goswami |
| author_sort | Partha Pratim Goswami |
| collection | DOAJ |
| description | We have performed detailed high-resolution spectroscopic analysis on seven metal-poor stars (BD+75 348, BD+09 3019, HD238020, HE0319–0215, HE0507–1653, HE0930–0018, HE1023–1504) and derived their atmospheric parameters T _eff , log g , [Fe/H], and microturbulent velocity ( ξ ). The metallicity range is found to be –2.57 < [Fe/H] < –0.42. The elemental abundances of 17 light elements and 12 heavy elements are estimated. We have classified BD+75 348 and BD+09 3019 as strong Ba stars, HD238020 as a mild Ba star, and the remaining four objects as CEMP- s stars. We have estimated the masses of the stars from Hertzsprung–Russel (HR) diagram, and, compiling the data of 205 Ba stars from literature, estimated the mass distribution of Ba stars. We have also estimated the initial masses of the companion AGBs of the program stars as well as the masses of the companion AGBs of 159 Ba and 36 CEMP- s stars from literature, with the help of a parametric-model-based analysis using FRUITY models. While the primary mass distribution of mild Ba stars peaks at 3.7 M _⊙ , for the strong Ba stars the peak appears at 2.5 M _⊙ . We, therefore, propose that the initial masses of the progenitor AGBs dominantly control the formation of mild and strong Ba stars. However, a clear overlap, in the range 1.3–4.0 M _⊙ , noticed between the progenitor masses of both the subclasses of Ba stars, may indicate that other factors, such as the metallicities and the orbital periods, may also have significant contributions. The progenitor AGBs’ mass distribution of CEMP- s stars is found to peak at 2.03 M _⊙ . |
| first_indexed | 2024-03-12T04:33:12Z |
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| institution | Directory Open Access Journal |
| issn | 1538-3881 |
| language | English |
| last_indexed | 2024-03-12T04:33:12Z |
| publishDate | 2023-01-01 |
| publisher | IOP Publishing |
| record_format | Article |
| series | The Astronomical Journal |
| spelling | doaj.art-c70cd63f05d34dce928a8bbc06cf556e2023-09-03T09:58:20ZengIOP PublishingThe Astronomical Journal1538-38812023-01-01165415410.3847/1538-3881/aca971Spectroscopic Study of Ba and CEMP-s Stars: Mass Distribution of AGB ProgenitorsPartha Pratim Goswami0https://orcid.org/0000-0002-5081-3208Aruna Goswami1https://orcid.org/0000-0002-8841-8641Indian Institute of Astrophysics , Koramangala, Bangalore 560034, India ; partha.pg@iiap.res.in, ppg0024@gmail.com; Pondicherry University , R.V. Nagar, Kalapet, 605014 Puducherry, IndiaIndian Institute of Astrophysics , Koramangala, Bangalore 560034, India ; partha.pg@iiap.res.in, ppg0024@gmail.comWe have performed detailed high-resolution spectroscopic analysis on seven metal-poor stars (BD+75 348, BD+09 3019, HD238020, HE0319–0215, HE0507–1653, HE0930–0018, HE1023–1504) and derived their atmospheric parameters T _eff , log g , [Fe/H], and microturbulent velocity ( ξ ). The metallicity range is found to be –2.57 < [Fe/H] < –0.42. The elemental abundances of 17 light elements and 12 heavy elements are estimated. We have classified BD+75 348 and BD+09 3019 as strong Ba stars, HD238020 as a mild Ba star, and the remaining four objects as CEMP- s stars. We have estimated the masses of the stars from Hertzsprung–Russel (HR) diagram, and, compiling the data of 205 Ba stars from literature, estimated the mass distribution of Ba stars. We have also estimated the initial masses of the companion AGBs of the program stars as well as the masses of the companion AGBs of 159 Ba and 36 CEMP- s stars from literature, with the help of a parametric-model-based analysis using FRUITY models. While the primary mass distribution of mild Ba stars peaks at 3.7 M _⊙ , for the strong Ba stars the peak appears at 2.5 M _⊙ . We, therefore, propose that the initial masses of the progenitor AGBs dominantly control the formation of mild and strong Ba stars. However, a clear overlap, in the range 1.3–4.0 M _⊙ , noticed between the progenitor masses of both the subclasses of Ba stars, may indicate that other factors, such as the metallicities and the orbital periods, may also have significant contributions. The progenitor AGBs’ mass distribution of CEMP- s stars is found to peak at 2.03 M _⊙ .https://doi.org/10.3847/1538-3881/aca971CEMP starsBarium starsCarbon starsChemically peculiar starsHertzsprung Russell diagramStellar physics |
| spellingShingle | Partha Pratim Goswami Aruna Goswami Spectroscopic Study of Ba and CEMP-s Stars: Mass Distribution of AGB Progenitors The Astronomical Journal CEMP stars Barium stars Carbon stars Chemically peculiar stars Hertzsprung Russell diagram Stellar physics |
| title | Spectroscopic Study of Ba and CEMP-s Stars: Mass Distribution of AGB Progenitors |
| title_full | Spectroscopic Study of Ba and CEMP-s Stars: Mass Distribution of AGB Progenitors |
| title_fullStr | Spectroscopic Study of Ba and CEMP-s Stars: Mass Distribution of AGB Progenitors |
| title_full_unstemmed | Spectroscopic Study of Ba and CEMP-s Stars: Mass Distribution of AGB Progenitors |
| title_short | Spectroscopic Study of Ba and CEMP-s Stars: Mass Distribution of AGB Progenitors |
| title_sort | spectroscopic study of ba and cemp s stars mass distribution of agb progenitors |
| topic | CEMP stars Barium stars Carbon stars Chemically peculiar stars Hertzsprung Russell diagram Stellar physics |
| url | https://doi.org/10.3847/1538-3881/aca971 |
| work_keys_str_mv | AT parthapratimgoswami spectroscopicstudyofbaandcempsstarsmassdistributionofagbprogenitors AT arunagoswami spectroscopicstudyofbaandcempsstarsmassdistributionofagbprogenitors |