冷 HgMn 星和热金属 A 星的均匀光谱与演化研究
A Homogeneous Spectroscopic and Evolutionary Study of cool HgMn and hot Metallic A Stars
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中文总结 AI 辅助
该研究对 HgMn 和 Am 子类恒星进行均匀光谱与演化分析，通过分析高分辨率光谱得出大气参数等，研究元素丰度温度依赖性，计算恒星演化模型，发现两类恒星可能占据重叠演化序列，需进一步分析检验子类间联系。
中文摘要 AI 辅助
我们对化学特殊恒星进行了均匀光谱和演化分析，重点关注 HgMn 和金属 A（Am）子类。特别关注最冷的 HgMn 星和最热的 Am 星，因为长期假说是它们可能代表相似恒星群体的连续演化阶段。分析了 13 颗 HgMn 和 14 颗 Am 目标的高分辨率光谱以得出大气参数和详细化学丰度。所有 HgMn 星都保持其化学特殊性，而 14 颗候选 Am 星中只有 6 颗表现出与真正 Am 特征一致的丰度模式。研究了元素丰度的温度依赖性，发现 Mn 丰度与有效温度呈正相关，Ni 呈负相关，支持原子扩散作用。用 MESA 代码根据光谱分析得出的大气参数计算恒星演化模型。已确认的 HgMn 和 Am 星在赫罗图中的位置支持冷 HgMn 星和热 Am 星可能占据重叠演化序列的可能性。虽然仅识别出有限数量的候选对，但需要使用包括原子扩散的演化模型进行进一步分析来检验这两个子类之间的可能联系。
英文摘要
We present a homogeneous spectroscopic and evolutionary analysis of chemically peculiar stars, focusing on HgMn and metallic A (Am) subclasses. Particular emphasis was placed on the coolest HgMn stars and the hottest Am stars, motivated by the long-standing hypothesis that these objects may represent consecutive evolutionary stages of a similar stellar population. High-resolution spectra of 13 HgMn and 14 Am targets were analyzed to derive atmospheric parameters and detailed chemical abundances. While all HgMn stars were confirmed to retain their chemically peculiar nature, only six of the fourteen candidate Am stars exhibit abundance patterns consistent with genuine Am characteristics, highlighting the importance of homogeneous spectroscopic classification. We investigate the temperature dependence of elemental abundances, finding a positive correlation between Mn abundance and $T_{\rm eff}$ and a negative correlation for Ni, supporting the operation of atomic diffusion. Stellar evolutionary models were computed with the MESA code using atmospheric parameters derived from the spectroscopic analysis. The locations of the confirmed HgMn and Am stars in the Hertzsprung--Russell diagram support the possibility that the cool HgMn stars and the hot Am stars may occupy overlapping evolutionary sequences. Although only a limited number of candidate pairs were identified, further analyses using evolutionary models that include atomic diffusion are needed to test the possible connection between the two subclasses.
