论文标题
来自汉堡/ESO调查的四个金属贫困碳星的光谱研究：确认其同伴的低质量性质
Spectroscopic study of four metal-poor carbon stars from the Hamburg/ESO Survey: On confirming the low-mass nature of their companions
论文作者
论文摘要
外部碳星的元素丰度提供了对早期银河系中元素的起源和演变的洞察力。在这项工作中，我们介绍了汉堡/ESO调查（HES）HE〜0457 $ - $ 1805，HE〜0920 $ 0506的四个潜在碳星候选者进行详细的光谱分析的结果，他〜1241 $ - $ - $ -0337，HE〜1327 $ - $ 21116。该分析基于使用Mercator/Hermes（R $ \ SIM $ 86,000）和Subaru/HDS（R $ \ sim $ 50,000）获得的高分辨率光谱。尽管从中分辨率光谱中获得了几个元素的丰度，例如，Fe，C和O，但我们提供了有史以来第一个针对这些对象的高分辨率高分辨率分析分析。对象He〜0457 $ - $ 1805和他〜1241 $ - $ 0337被发现为CEMP-S星，他〜0920 $ - $ 0506 A CH Star，他〜1327 $ - $ 2116 A CEMP-R/S Star。对象He〜0457 $ - $ 1805是确认的二进制文件，而其他对象的二进制状态未知。在绝对碳丰度A（c）与[Fe/H]图点上的二进制性质上的程序明星的位置。我们已经检查了程序明星的各种元素丰度比，并确认了其前AGB同伴的低质性质。我们已经表明，I-Process模型可以成功地重现He〜1327 $ -2116的观察到的丰度模式。基于参数模型的分析为He〜0457 $ - $ 1805，HE〜0920 $ -0506进行，并且基于果味模型，他〜1241 $ - $ 0337证实，这三个对象的表面化学成分受到低层AGB同伴的污染影响。
Elemental abundances of extrinsic carbon stars provide insight into the poorly understood origin and evolution of elements in the early Galaxy. In this work, we present the results of a detailed spectroscopic analysis of four potential carbon star candidates from the Hamburg/ESO Survey (HES) HE~0457$-$1805, HE~0920$-$0506, HE~1241$-$0337, and HE~1327$-$2116. This analysis is based on the high-resolution spectra obtained with Mercator/HERMES (R$\sim$86,000) and SUBARU/HDS (R$\sim$50,000). Although the abundances of a few elements, such as, Fe, C, and O are available from medium-resolution spectra, we present the first ever detailed high-resolution spectroscopic analysis for these objects. The object HE~0457$-$1805 and HE~1241$-$0337 are found to be CEMP-s stars, HE~0920$-$0506 a CH star, and HE~1327$-$2116 a CEMP-r/s star. The object HE~0457$-$1805 is a confirmed binary, whereas the binary status of the other objects is unknown. The locations of program stars on the absolute carbon abundance A(C) vs [Fe/H] diagram point at their binary nature. We have examined various elemental abundance ratios of the program stars and confirmed the low-mass nature of their former AGB companions. We have shown that the i-process models could successfully reproduce the observed abundance pattern in HE~1327$-$2116. The parametric model based analysis performed for HE~0457$-$1805, HE~0920$-$0506, and HE~1241$-$0337 based on the FRUITY models confirmed that the surface chemical composition of these three objects are influenced by pollution from low-mass AGB companions.
