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| Verfasst von: | François, Patrick [VerfasserIn]  |
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| | Caffau, Elisabetta [VerfasserIn] |
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| | Christlieb, Norbert [VerfasserIn] |
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| | Klessen, Ralf S. [VerfasserIn] |
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| | Koch-Hansen, Andreas [VerfasserIn] |
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| | Ludwig, Hans-Günter [VerfasserIn] |
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| Titel: | TOPoS |
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| Titelzusatz: | V: Abundance ratios in a sample of very metal-poor turn-off stars |
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| Verf.angabe: | P. François, E. Caffau, P. Bonifacio, M. Spite, F. Spite, R. Cayrel, N. Christlieb, A. J. Gallagher, R. Klessen, A. Koch, H.-G. Ludwig, L. Monaco, B. Plez, M. Steffen, and S. Zaggia |
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| E-Jahr: | 2018 |
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| Jahr: | 31 Oct 2018 |
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| Umfang: | 17 S. |
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| Fussnoten: | Gesehen am 16.10.2020 |
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| Titel Quelle: | Enthalten in: De.arxiv.org |
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| Ort Quelle: | [S.l.] : Arxiv.org, 1991 |
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| Jahr Quelle: | 2018 |
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| Band/Heft Quelle: | (2018) Artikel-Nummer 1811.00035, 17 Seiten |
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| Abstract: | Extremely metal-poor stars are keys to understand the early evolution of our Galaxy. The ESO large programme TOPoS has been tailored to analyse a new set of metal-poor turn-off stars, whereas most of the previously known extremely metal-poor stars are giant stars. Sixty five turn-off stars (preselected from SDSS spectra) have been observed with the X-Shooter spectrograph at the ESO VLT Unit Telescope 2, to derive accurate and detailed abundances of magnesium, silicon, calcium, iron, strontium and barium. We analysed medium-resolution spectra (R ~ 10 000) obtained with the ESO X-Shooter spectrograph and computed the abundances of several alpha and neutron-capture elements using standard one-dimensional local thermodynamic equilibrium (1D LTE) model atmospheres. Our results confirms the super-solar [Mg/Fe] and [Ca/Fe] ratios in metal-poor turn-off stars as observed in metal-poor giant stars. We found a significant spread of the [alpha/Fe] ratios with several stars showing sub-solar [Ca/Fe] ratios. We could measure the abundance of strontium in 12 stars of the sample, leading to abundance ratios [Sr/Fe] around the Solar value. We detected barium in two stars of the sample. One of the stars (SDSS J114424-004658) shows both very high [Ba/Fe] and [Sr/Fe] abundance ratios (>1 dex). |
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| URL: | Bitte beachten Sie: Dies ist ein Bibliographieeintrag. Ein Volltextzugriff für Mitglieder der Universität besteht hier nur, falls für die entsprechende Zeitschrift/den entsprechenden Sammelband ein Abonnement besteht oder es sich um einen OpenAccess-Titel handelt.
Volltext: http://arxiv.org/abs/1811.00035 |
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| Datenträger: | Online-Ressource |
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| Sprache: | eng |
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| Sach-SW: | Astrophysics - Solar and Stellar Astrophysics |
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| K10plus-PPN: | 1586572393 |
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| Verknüpfungen: | → Sammelwerk |
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