SYSTEMATIC NON-LTE STUDY OF THE −2.6 ≤ [Fe/H] ≤ 0.2 F AND G DWARFS IN THE SOLAR NEIGHBORHOOD. II. ABUNDANCE PATTERNS FROM Li TO Eu*

Zhao, Gang; Mashonkina, L.; Yan, Hui‐Juan; Alexeeva, Sofya; Kobayashi, Chiaki; Pakhomov, Yu. V.; Shi, Jianrong; Sitnova, T.; Tan, Kefeng; Zhang, H. W.; Zhang, J. B.; Zhou, Zhenlei; Bolte, Michael; Chen, Y. Q.; Li, X.; Liu, F.; Zhai, M.

doi:10.3847/1538-4357/833/2/225

Cited by 137 publications

(205 citation statements)

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“…As a consequence the silicon abundance found in the UV in HD 84937 is compatible with the results of Bonifacio et al (2009). As for Mg and Ca, our [Si/H] value is very close to the value found by Zhao et al (2016), and the small difference in [Si/Fe] is attributed to the adopted [Fe/H] values.…”

Section: Silicon Abundancesupporting

confidence: 78%

“…For the optical Mg i lines in Table 1, we adopted the non-LTE correction computed by Zhao et al (2016) and we found a mild overabundance of Mg ( Zhao et al (2016). This value is also in good agreement with the value we deduce from the wings of the very strong Mg ii h and k lines around 280 nm ([Mg/Fe] LTE = +0.26 dex).…”

Section: Abundances Of Classical α Elements: Magnesium and Calciumsupporting

confidence: 72%

“…HD 84937 is a bright, (V = 8.32, Ducati 2002) very metalpoor, main-sequence turnoff star, often used as a reference for the field metal-poor stars (lately: Lawler et al 2015), and consequently has recently been widely studied from spectra in the visible domain (Gehren et al 2006;Lai et al 2007;Mashonkina et al 2011;Bergemann et al 2012;Lind et al 2013;VandenBerg et al 2014;Sneden et al 2016;Amarsi et al 2016;Zhao et al 2016). The model parameters are very similar in all these studies.…”

Section: Introductionmentioning

confidence: 80%

“…We have three lines in common with Zhao et al (2016), and the non-LTE corrections for these lines do not differ by more than 0.02 dex. The Ca abundance found in HD 84937 is in very good agreement with the mean abundances obtained, using the same set of lines, for EMP turnoff stars with −3.6 < [Fe/H] < −2.5 (Bonifacio et al 2009;Spite et al 2012).…”

Section: Abundances Of Classical α Elements: Magnesium and Calciummentioning

confidence: 99%

“…3). The non-LTE correction (−0.12 dex) was adopted from the calculations of Zhao et al (2016) (Masseron et al 2014) were included in the synthesis. The result is presented in Fig.…”

Section: Carbon and Oxygen Abundancesmentioning

confidence: 99%

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Abundances of the light elements from UV (HST) and red (ESO) spectra in the very old star HD 84937

Spite

Peterson

Gallagher

et al. 2017

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Aims. In order to provide a better basis for the study of mechanisms of nucleosynthesis of the light elements beyond hydrogen and helium in the oldest stars, the abundances of C, O, Mg, Si, P, S, K, and Ca have been derived from UV-HST and visible-ESO high resolution spectra in the old, very metal-poor star HD 84937, at a metallicity that is 1/200 that of the Sun's. For this halo main-sequence turnoff star, the abundance determination of P and S are the first published determinations. Methods. The LTE profiles of the lines were computed and fitted to the observed spectra. Wherever possible, we compared the abundances derived from the UV spectrum to abundances derived from the visible or near-infrared spectra, and also corrected the derived abundances for non-LTE effects. Three-dimensional (3D) CO 5 BOLD model atmospheres have been used to determine the abundances of C and O from molecular CH and OH bands. Results. The abundances of these light elements relative to iron in HD 84937 are found to agree well with the abundances of these elements in classical metal-poor stars. Our HD 84937 carbon abundance determination points toward a solar (or mildly enhanced above solar) value of [C/Fe]. The modest overabundance of the α elements of even atomic number Z, typical of halo turnoff stars, is confirmed in this example. The odd-Z element P is found to be somewhat deficient in HD 84937, at [P/Fe] = −0.32, which is again consistent with the handful of existing determinations for turnoff stars of such low metallicity. We show that the abundance of oxygen, deduced from the OH band from 3D computations, is not compatible with the abundance deduced from the red oxygen triplet. This incompatibility is explained by the existence of a chromosphere heating the shallow layers of the atmosphere where the OH band, in 3D computations, is mainly formed. Conclusions. The abundance ratios are compared to the predictions of models of galactic nucleosynthesis and evolution.

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Section: Silicon Abundancesupporting

confidence: 78%

Section: Abundances Of Classical α Elements: Magnesium and Calciumsupporting

confidence: 72%

Section: Introductionmentioning

confidence: 80%

Section: Abundances Of Classical α Elements: Magnesium and Calciummentioning

confidence: 99%

“…3). The non-LTE correction (−0.12 dex) was adopted from the calculations of Zhao et al (2016) (Masseron et al 2014) were included in the synthesis. The result is presented in Fig.…”

Section: Carbon and Oxygen Abundancesmentioning

confidence: 99%

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