Academic Journal
High-resolution spectroscopic study of extremely metal-poor stars in the Large Magellanic Cloud
| العنوان: | High-resolution spectroscopic study of extremely metal-poor stars in the Large Magellanic Cloud |
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| المؤلفون: | Oh, W S, Nordlander, T, Da Costa, G S, Bessell, M S, Mackey, A D |
| المساهمون: | European Southern Observatory |
| المصدر: | Monthly Notices of the Royal Astronomical Society ; volume 528, issue 1, page 1065-1080 ; ISSN 0035-8711 1365-2966 |
| بيانات النشر: | Oxford University Press (OUP) |
| سنة النشر: | 2024 |
| الوصف: | We present detailed abundance results based on Ultraviolet and Visual Echelle Spectrograph high-dispersion spectra for seven very and extremely metal-poor stars in the Large Magellanic Cloud (LMC). We confirm that all seven stars, two of which have [Fe/H] ≤ −3.0, are the most metal-poor stars discovered so far in the Magellanic Clouds. The element abundance ratios are generally consistent with Milky Way halo stars of similar [Fe/H] values. We find that two of the more metal-rich stars in our sample are enhanced in r-process elements. This result contrasts with the literature, where all nine metal-poor LMC stars with higher [Fe/H] values than our sample were found to be rich in r-process elements. The absence of r-process enrichment in stars with lower [Fe/H] values is consistent with a minimum delay time-scale of ∼100 Myr for the neutron star binary merger process to generate substantial r-process enhancements in the LMC. We find that the occurrence rate of r-process enhancement (r-I or r-II) in our sample of very and extremely metal-poor stars is statistically indistinguishable from that found in the Milky Way’s halo, although including stars from the literature sample hints at a larger r-II frequency the LMC. Overall, our results shed light on the earliest epochs of star formation in the LMC that may be applicable to other galaxies of LMC-like mass. |
| نوع الوثيقة: | article in journal/newspaper |
| اللغة: | English |
| DOI: | 10.1093/mnras/stae081 |
| DOI: | 10.1093/mnras/stae081/55403862/stae081.pdf |
| الاتاحة: | http://dx.doi.org/10.1093/mnras/stae081 https://academic.oup.com/mnras/advance-article-pdf/doi/10.1093/mnras/stae081/55403862/stae081.pdf https://academic.oup.com/mnras/article-pdf/528/1/1065/56332918/stae081.pdf |
| Rights: | https://creativecommons.org/licenses/by/4.0/ |
| رقم الانضمام: | edsbas.7425B816 |
| قاعدة البيانات: | BASE |
| DOI: | 10.1093/mnras/stae081 |
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