| Autor: |
Qianfan Xing, Gang Zhao, Yue-Fei Wang, Yue Wu, Yong-Hui Hou, Yong Zhang |
| Rok vydání: |
2015 |
| Předmět: |
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| Zdroj: |
Research in Astronomy and Astrophysics. 15:1275-1281 |
| ISSN: |
1674-4527 |
| DOI: |
10.1088/1674-4527/15/8/012 |
| Popis: |
Most Galactic metal-poor stars exhibit enhanced α-abundances (e.g. [Mg/Fe] ~ +0.4) according to previous studies of stellar chemical compositions. However, a handful of metal-poor stars with large deficiencies in Mg (e.g. [Mg/Fe] ~ −0.2) show severe departures from this α-enhancement trend. The sub-solar [Mg/Fe] ratios of these anomalous stars indicate that they possess different chemical enrichment histories than the majority of Galactic metal-poor stars. In previous work, we presented a method to select Mg-poor metal-poor stars from low-resolution SDSS spectra based on a spectral matching technique. In this paper, a similar method is applied to low-resolution ( R ~ 1800) LAMOST spectra. Stellar [Mg/Fe] abundances are determined by using stellar parameters delivered by the LAMOST Data Release 2 catalog. From a sample of ~ 60 000 stars with atmospheric parameters in the range T eff = [5500, 6500] K and [Fe/H] = [−2.4, +0.5], we select 15 candidate Mg-poor metal-poor stars. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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