A Metallicity Study of F, G, K, and M Dwarfs in the Coma Berenices Open Cluster from the APOGEE Survey
A Metallicity Study of F, G, K, and M Dwarfs in the Coma Berenices Open Cluster from the APOGEE Survey
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DOI：
10.3847/1538-4357/abfdb5
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发表时间：
2021-05
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影响因子：
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通讯作者：
D. Souto;K. Cunha;V. Smith
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文献类型：
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作者：
D. Souto;K. Cunha;V. Smith
本文研究了属于太阳邻域年轻疏散星团后发座的M、K、G和F型主序星（T_eff = 3200- 6500 K，log g = 4.3-5.0 dex）的金属丰度。使用斯隆数字巡天IV APOGEE巡天的高分辨率（R = λ/Δ λ = 22，500）近红外光谱（λ1.51-λ1.69 μm）确定金属丰度。该星系团的成员资格是使用文献中之前的研究以及APOGEE径向速度和Gaia DR 2沿着确认的。LTE分析采用平面平行MARCS模式大气和APOGEE DR 16线列表计算合成光谱和推导大气参数（Teff和log g）的M矮星和样品的金属丰度。推导出的金属丰度是近太阳和均匀的预期的不确定性的水平，特别是当考虑从一个给定的恒星类的恒星。G型、K型和M型矮星的平均金属丰度计算结果为：[Fe/H]= +0.04 ± 0.02 dex;然而，F型恒星的金属丰度比温度较低、质量较小的成员略低，约为0.04 dex。原子扩散的模型可以解释F矮星的这种适度的丰度下降，表明后发座恒星中的原子扩散。[Fe/H]浸发生在几乎相同的有效温度范围内，发现在以前的分析中的锂和铍丰度后发座。
We present a study of metallicities in a sample of main-sequence stars with spectral types M, K, G, and F (T eff ∼3200–6500K and log g ∼ 4.3–5.0 dex) belonging to the solar neighborhood young open cluster Coma Berenices. Metallicities were determined using the high-resolution (R = λ/Δ λ ∼ 22,500) NIR spectra (λ1.51–λ1.69 μm) of the Sloan Digital Sky Survey IV APOGEE survey. Membership to the cluster was confirmed using previous studies in the literature along with APOGEE radial velocities and Gaia DR2. An LTE analysis using plane-parallel MARCS model atmospheres and the APOGEE DR16 line list was adopted to compute synthetic spectra and derive atmospheric parameters (T eff and log g) for the M dwarfs and metallicities for the sample. The derived metallicities are near-solar and are homogeneous at the level of the expected uncertainties, in particular when considering stars from a given stellar class. The mean metallicity computed for the sample of G, K, and M dwarfs is 〈[Fe/H]〉 = +0.04 ± 0.02 dex; however, the metallicities of the F-type stars are slightly lower, by about 0.04 dex, when compared to cooler and less massive members. Models of atomic diffusion can explain this modest abundance dip for the F dwarfs, indicating that atomic diffusion operates in Coma Berenices stars. The [Fe/H] dip occurs in nearly the same effective temperature range as that found in previous analyses of the lithium and beryllium abundances in Coma Berenices.