Evolution of the titanium and oxygen abundances from observations of FGK dwarfs in a wide metallicity range
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- 作者：T. M. Sitnova
- 关键词：Galactic chemical evolution ; oxygen and titanium abundances in stars ; spectral line formation under nonequilibrium conditions
- 刊名：Astronomy Letters
- 出版年：2016
- 出版时间：November 2016
- 年：2016
- 卷：42
- 期：11
- 页码：734-744
- 全文大小：948 KB
- 刊物类别：Physics and Astronomy
- 刊物主题：Physics
Astronomy
Astrophysics
Russian Library of Science - 出版者：MAIK Nauka/Interperiodica distributed exclusively by Springer Science+Business Media LLC.
- ISSN：1562-6873
- 卷排序：42
文摘
For a sample of dwarf stars close to the Sun with well-known atmospheric parameters and an iron abundance in the range −2.6 < [Fe/H] < 0.2, we have determined the titanium and oxygen abundances by taking into account the departures from LTE. The dependence of the [O/Fe] and [Ti/Fe] abundance ratios on [Fe/H] has been refined in comparison with the published data. We have established that [O/Fe] increases from −0.2 to 0.6 as the metallicity [Fe/H] decreases from 0.2 to −0.8 and remains constant at a lower metallicity. A similar behavior has been found for [Ti/Fe], but the plateau is formed by stars with [Fe/H] > −0.7, and the titanium overabundance relative to iron is 0.3. The results confirm that not only oxygen but also titanium are synthesized in the α-process. Our data can be used to test the Galactic chemical evolution models.