论文标题
我们如何从综合光谱的光谱拟合中确定年龄和化学丰度？
How well can we determine ages and chemical abundances from spectral fitting of integrated light spectra?
论文作者
论文摘要
像素到像素光谱拟合技术经常用于恒星种群的研究。它使用户能够从综合光谱（例如年龄和化学丰度）中推断出几个参数。在本文中，我们研究了有关所使用的波长范围的选择如何变化的问题。我们已经采用了两个不同的球状簇（GC）集成光谱的库，并使用Code Starlight将它们拟合到了出色的人口模型。我们使用光谱的不同区域进行了测试，以推断[Fe/H]和[alpha/fe]变红，年龄。将我们的结果与从高分辨率光谱法获得的年龄值和化学丰度获得的年龄值进行比较，我们发现：（1）被推断的参数随所使用的波长范围而变化； （2）通常，该方法检索良好的红色估计值，特别是当拟合更宽的波长范围时； （3）确定年龄，[fe/h]和[alpha/fe]的理想频谱区域分别为：4170-5540A，5280-7020a和4828-5364a； （4）旧金属贫困物体的年龄值可能比等质型拟合产生的年龄要年轻。我们得出的结论是，根据感兴趣的参数和准确性要求，适合最大可能的波长范围可能不一定是最佳策略。
The pixel-to-pixel spectral fitting technique is often used in studies of stellar populations. It enables the user to infer several parameters from integrated light spectra such as ages and chemical abundances. In this paper, we examine the question of how the inferred parameters change with the choice of wavelength range used. We have employed two different libraries of integrated light spectra of globular clusters (GCs) from the literature and fitted them to stellar population models using the code Starlight. We performed tests using different regions of the spectra to infer reddening, ages, [Fe/H] and [alpha/Fe]. Comparing our results to age values obtained from isochrone fitting and chemical abundances from high resolution spectroscopy, we find that: (1) The inferred parameters change with the wavelength range used; (2) The method in general retrieves good reddening estimates, specially when a wider wavelength range is fitted; (3) The ideal spectral regions for determination of age, [Fe/H], and [alpha/Fe] are: 4170-5540A, 5280-7020A, and 4828-5364A, respectively; (4) The retrieved age values for old metal-poor objects can be several Gyr younger than those resulting from isochrone fitting. We conclude that, depending on the parameter of interest and the accuracy requirements, fitting the largest possible wavelength range may not necessarily be the best strategy.
