论文标题
表面亮度波动光谱以限制恒星种群特性
Surface Brightness Fluctuation spectra to constrain stellar population properties
论文作者
论文摘要
我们提供了一组新的表面亮度波动光谱，该光谱是通过E-Miles恒星种群合成模型计算的。模型SBF光谱涵盖了中等高分辨率的1680-50000埃埃斯特罗姆的范围，这都是基于广泛的经验恒星库。对于具有不同斜率的IMF类型的套件，这些型号跨越了金属度范围-2.3 <[m/h <+0.26。这些预测可以补充和辅助波动的大小研究，从而通过对SBF光谱应用过滤器响应来获得光谱SBF幅度，从而允许一阶近似。我们提供了获取后者并讨论其不确定性和局限性的食谱。我们将光谱SBF幅度与早期型星系样品的光度数据进行了比较。我们还表明，SBF光谱对于限制相关恒星种群参数非常有用。我们发现在极端富裕，旧且金属富裕的恒星种群的顶部，极度金属贫困组件（[m/h] <-1）的质量很小（[m/h] <-1）。这些结果对大型椭圆星系中星系形成的早期阶段施加了严格的限制。鉴于标准光谱分析对可见的和近IR中的这种金属贫困恒星种群的高度堕落性，这是显着的。新的SBF模型具有开发正在进行的调查的巨大潜力，尤其是基于窄带过滤器的调查。
We present a new set of Surface Brightness Fluctuation spectra computed with the E-MILES stellar population synthesis models. The model SBF spectra cover the range 1680-50000 Angstrom at moderately high resolution, all based on extensive empirical stellar libraries. The models span the metallicity range -2.3<[M/H<+0.26 for a suite of IMF types with varying slopes. These predictions can complement and aid fluctuation magnitudes studies, permitting a first order approximation by applying filter responses to the SBF spectra to obtain spectroscopic SBF magnitudes. We provide a recipe for obtaining the latter and discuss their uncertainties and limitations. We compare our spectroscopic SBF magnitudes to photometric data of a sample of early-type galaxies. We also show that the SBF spectra can be very useful for constraining relevant stellar population parameters. We find small (<5%) mass-fractions of extremely metal-poor components ([M/H]<-1) on the top of the dominant, old and metal-rich stellar population. These results put stringent constraints on the early stages of galaxy formation in massive elliptical galaxies. This is remarkable given the high degree of degeneracy of the standard spectral analysis to such metal-poor stellar populations in the visible and in the near-IR. The new SBF models show great potential for exploiting ongoing surveys, particularly those based on narrow-band filters.
