论文标题
综合光恒星种群模型和本地组星系中的化学特殊恒星
Chemically Peculiar Stars in Integrated Light Stellar Population Models and Local Group Galaxies
论文作者
论文摘要
使用合成光谱组装成化学特征（CP）恒星的常见类型的集成轻型模型。选定的光谱功能编码年龄$ \ sim $ 50 MYR $ <$ <$ age $ <\ sim $ 2 GYR的大量年龄信息。由于模板不匹配的减轻，在模型光谱中包含CP Star特征可提高恢复的出色群体人口参数的准确性，但我们无法证明与连续拟合和强大功能强度相比，至少在目前的艺术状态下，可以从弱的CP特征中提取新的或独特的年龄信息。恢复2-繁殖年龄结构的年龄抢劫常规用于分析当地组星系的光谱。 NGC 224（M31）的恒星种群太老了，无法使用我们检查的CP恒星类型。 NGC 221（M32）也没有CP光谱特征。除了其主要的4.7 GYR人群外，它似乎在$ \ sim $ \ sim $ 1时，占1％的成分。与SDSS星系平均值不同，NGC 205（M110）不包含由于HGMN恒星的特征。这不包括与HGMN生产相关的年龄范围，其近核频谱最适合68美元$ \ pm $ 2 $ 2 MYR人口叠加在老年人群上，其中1.85美元$ \ pm $ 0.1 $ 0.1 GYR成分。 NGC 205和NGC 221都有一个古老的组成部分，鉴于年轻人群的压倒性光优势，其质量不容易约束。
Integrated-light models that incorporate common types of chemically peculiar (CP) stars are assembled using synthetic spectra. Selected spectral features encode significant age information for populations with ages $\sim$50 Myr $<$ age $< \sim$2 Gyr. Due to the alleviation of template mismatch, the inclusion of CP star features in model spectra improves the accuracy of recovered stellar population parameters, but we are not able to show that new or unique age information can be extracted from the weak CP features compared to continuum fitting and strong-feature strengths, at least at the present state of the art. An age-extraction routine that recovers 2- and 3-burst age structures is employed to analyze the spectra of local group galaxies. NGC 224 (M31) has a stellar population too old for the types of CP stars we examine. NGC 221 (M32) also shows no CP spectral features. It appears to contain a component at age $\sim$1 Gyr at 1% by mass in addition to its dominant 4.7 Gyr population. Unlike SDSS galaxy spectrum averages, NGC 205 (M110) contains no features due to HgMn stars. This excludes the age range associated with HgMn production, and its near-nuclear spectrum is best fit by a 68$\pm$2 Myr population superimposed on an older population with a 1.85$\pm$0.1 Gyr component. Both NGC 205 and NGC 221 have an ancient component whose mass is not easy to constrain given the overwhelming light-dominance of the younger populations.
