论文标题
局部磁盘和光晕的化学特性。 ii。从低分辨率光谱的改进模型拟合中的3745 m矮人和细分的丰度
Chemical Properties of the Local Disk and Halo. II. Abundances of 3745 M dwarfs and Subdwarfs from Improved Model Fitting of Low-Resolution Spectra
论文作者
论文摘要
我们提出了一条模型拟合管道，以确定M型矮人的恒星参数，这是对我们先前在Hejazi等人中描述的工作的改进。 2020年。我们应用此管道来分析3745 m矮人/subdwarfs的低分辨率（R〜2000）光谱，该光谱是在MDM天文台，Lick天文台，基特峰国家天文台和Cerro Tololo tololo Intererican Intererican Perservatory收集的。我们研究了由盖亚（Gaia）早期数据版本3（EDR3）视差和光学幅度构建的HR图中推断参数值的变化。我们还研究了恒星在[alpha/fe]与[m/h]的丰度图中的分布，并检查其金属性类别，有效温度和表面重力以及其银河速度成分U，V和W的变化。此外，对恒星在二维紫外线，大众和UW平面中的预测运动的分析以及它们在这些平面中的化学参数的变化，以及它们在丰度速度图中的分布也是本研究的重要部分。我们的模型拟合管道的精度通过在人力资源图中的有效温度和化学参数的明确分层，恒星在[alpha/fe]与[m/h]图中的相似性与[M/h]图的相似性以及金属级别的相似性以及与其他研究中的金属级别的相似性相似，并揭示了在丰度 - 级别的构图中的构图和化学系统中的构图。
We present a model-fit pipeline to determine the stellar parameters of M-type dwarfs, which is an improvement upon our previous work described in Hejazi et al. 2020. We apply this pipeline to analyze the low-resolution (R~2000) spectra of 3745 M dwarfs/subdwarfs, collected at the MDM Observatory, Lick Observatory, Kitt Peak National Observatory, and Cerro Tololo Interamerican Observatory. We examine the variation of the inferred parameter values in the HR diagram constructed from their Gaia Early Data Release 3 (EDR3) parallaxes and optical magnitudes. We also study the distribution of our stars in the abundance diagram of [alpha/Fe] versus [M/H] and inspect the variation of their metallicity class, effective temperature, and surface gravity as well as their Galactic velocity components U, V, and W in this diagram. In addition, the analyses of the stars' projected motions in the two-dimensional UV, VW, and UW planes and the variation of their chemical parameters in these planes, and also their distribution in the abundance-velocity diagrams are important parts of this study. The precision of our model-fit pipeline is confirmed by the clear stratification of effective temperature and chemical parameters in the HR diagram, the similarity of the stars' distribution in the [alpha/Fe] versus [M/H] diagram and in the metallicity-velocity planes with those from other studies, revealing substructure in the abundance-velocity diagrams, and chemical homogeneity between the components of a set of binary systems.
