论文标题
三个银河簇中的硫丰度：Ruprecht 106，Trumpler 5和Trumpler 20
Sulfur abundances in three Galactic clusters: Ruprecht 106, Trumpler 5 and Trumpler 20
论文作者
论文摘要
语境。硫是较少研究的$α$元素之一。迄今为止，已发表了有关其行为的研究集中在当地恒星上，仅考虑了银河系的少数集群来研究该主题。我们旨在研究球状簇Ruprecht 106的S含量 - 为此目的从未对此进行研究，但已知呈现低水平的[$α$/fe]丰度比 - 驱动群集Trumpler 5。开放式群集Trumpler 5。到目前为止，在Trumpler 5中研究的唯一恒星显示出了S. Aim的出乎意料的低度。通过这项工作，我们旨在提供Ruprecht 106中的第一个S丰度，并用较大的恒星样品研究Trumpler 5的S含量。开放群集符号20被视为参考对象。方法。我们基于局部热力学平衡（LTE）以及高分辨率和高信号到液位的uves uves-slit和uves/uves/flames/flames光谱的标准丰度分析。我们还对非LTE进行了更正。通过研究等效宽度获得目标的金属性。硫的丰度源自谱图源自多重1、6和8。结果。我们发现Ruprecht 106和Trumpler 5的金属度分别为[Fe/H] = -1.37 +/- 0.11和[Fe/H] = -0.49 +/- 0.14。 Ruprecht 106比其他类似金属性的银河系簇少。 Ruprecht 106，[s/fe] NLTE = -0.52 +/- 0.13的低含量与其$α$ - 元素的短缺一致。这支持了该集群的半乳酸外。我们获得了大约[s/fe] nlte = 0.05 +/- 0.20的trumpler 5的新的且更强大的S含量值。根据我们的结果，Trumpler 5遵循[S/Fe] LTE与[Fe/H]图中银河磁盘的趋势。我们对trumpler 20的结果，即[fe/h] = 0.06 +/- 0.15和[s/fe] nlte = -0.28 +/- 0.21，与文献中的结果一致。
Context. Sulfur (S) is one of the lesser-studied $α$-elements. Published investigations of its behavior have so far focused on local stars, and only a few clusters of the Milky Way have been considered to study this topic. We aim to study the S content of the globular cluster Ruprecht 106 -- which has never before been studied for this purpose, but is known to present low levels of the [$α$/Fe] abundance ratio -- and the open cluster Trumpler 5. The only star studied so far in Trumpler 5 shows an unexpectedly low abundance of S. Aims. With this work, we aim to provide the first S abundance in Ruprecht 106 and to investigate the S content of Trumpler 5 with a larger sample of stars. The open cluster Trumpler 20 is considered as a reference object. Methods. We performed a standard abundance analysis based on 1D model atmospheres in local thermodynamical equilibrium (LTE) and on high-resolution and high-signal-to-noise-ratio UVES-slit and UVES/FLAMES spectra. We also applied corrections for nonLTE. The metallicities of the targets were obtained by studying equivalent widths. Sulfur abundances were derived from multiplets 1, 6, and 8 by spectrosynthesis. Results. We find that the metallicities of Ruprecht 106 and Trumpler 5 are [Fe/H]= -1.37+/-0.11 and [Fe/H]= -0.49+/-0.14, respectively. Ruprecht 106 is less S-rich than the other Galactic clusters at similar metallicity. The low S content of Ruprecht 106, [S/Fe]NLTE= -0.52+/-0.13, is consistent with its shortage of $α$-elements. This supports an extra-galactic origin of this cluster. We obtained a new and more robust S content value of Trumpler 5 of about [S/Fe]NLTE= 0.05+/-0.20. According to our results, Trumpler 5 follows the trend of the Galactic disk in the [S/Fe]LTE versus [Fe/H] diagram. Our results for Trumpler 20, of namely [Fe/H]= 0.06+/-0.15 and [S/Fe]NLTE= -0.28+/-0.21, are in agreement with those in the literature.
