Evolutionary population synthesis: models, analysis of the ingredients and application to high‐z galaxies
Evolutionary population synthesis: models, analysis of the ingredients and application to high‐z galaxies
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DOI：
10.1111/j.1365-2966.2005.09270.x
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发表时间：
2004-10
影响因子：
4.8
通讯作者：
C. Maraston
中科院分区：
文献类型：
--
作者：
C. Maraston
演化人口合成模型的金属丰度，年龄，星星形成历史，初始质量函数和水平分支形态，包括蓝色形态在高金属丰度，计算。该模型的输出包括光谱能量分布、颜色、恒星M/L比、热辐射校正和近红外光谱线指数。用燃料消耗定理对主序后演化阶段的能量学进行了评价。对恒星演化轨迹模型的影响（特别是有和没有过冲）进行了评估。我们发现在我们的代码中使用不同的轨道引起的合成宽带颜色的适度差异[例如，（V-K）= 0.08 mag，（B）= 0.03 mag]。值得注意的是，这些差异大大小于文献中其他模型之间的分散，即使后者采用相同的进化轨迹。这些模型是用来自银河系的球状星团数据进行校准的，用于年老的，麦哲伦云加上合并残余星系NGC 7252，两者都是年轻的，年龄为10.1 - 2 Gyr，在U波段到K波段的大波长范围内。特别强调的是从热脉冲渐近巨分支（TP-AGB）相的贡献。我们表明，这一演化阶段是至关重要的年轻恒星种群的建模直接比较观测到的光谱能量分布的麦哲伦星团，其特点是相对较高的通量，无论是蓝向和红向的V波段。我们发现，近红外光谱指数C2和H2O的组合可以用来确定的金属丰度的Gyr恒星种群。作为一个说明性的应用，我们重新分析了一些高z星系的光谱能量分布（2.4 z 2.9）由斯皮策太空望远镜观察到的Yan等人。他们的高静止帧近红外通量与模型，包括TP-AGB星的年龄范围在1.00 - 0.6 - 1.5 Gyr，非常好地再现，这表明这些对象的形成红移约为z 1.03 - 6。Ke yw ords：stars：AGB and post-AGB-stars：evolution-galaxies：evolution-galaxies：stellar content-cosmology：early Universe.
Evolutionary population synthesis models for a wide range of metallicities, ages, star formation histories, initial mass functions and horizontal branch morphologies, including blue morphologies at high metallicity, are computed. The model output comprises spectral energy distributions, colours, stellar M/L ratios, bolometric corrections and near-infrared (IR) spectral line indices. The energetics of the post main sequence evolutionary phases are evaluated with the fuel consumption theorem. The impact on the models of the stellar evolutionary tracks (in particular with and without overshooting) is assessed. We find modest differences in synthetic broad-band colours as induced by the use of different tracks in our code [e.g. �( V − K ) ∼ 0.08 mag, �( B − V ) ∼ 0.03 mag]. Noticeably, these differences are substantially smaller than the scatter among other models in the literature, even when the latter adopt the same evolutionary tracks. The models are calibrated with globular cluster data from the Milky Way for old ages, and the Magellanic clouds plus the merger remnant galaxy NGC 7252, both for young ages of ∼0.1‐2 Gyr, in a large wavelength range from the U band to the K band. Particular emphasis is put on the contribution from the thermally pulsing asymptotic giant branch (TP-AGB) phase. We show that this evolutionary phase is crucial for the modelling of young stellar populations by direct comparison with observed spectral energy distributions of Magellanic cloud clusters, which are characterized by relatively high fluxes, both blueward and redward of the V band. We find that the combination of the near-IR spectral indices C2 and H2O can be used to determine the metallicity of ∼1 Gyr stellar populations. As an illustrative application, we re-analyse the spectral energy distributions of some of the high-z galaxies (2.4 z 2.9) observed with the Spitzer Space Telescope by Yan et al. Their high rest-frame near-IR fluxes is reproduced very well with the models including TP-AGB stars for ages in the range ∼0.6‐1.5 Gyr, suggesting formation redshifts for these objects around z ∼ 3‐6. Ke yw ords: stars: AGB and post-AGB ‐ stars: evolution ‐ galaxies: evolution ‐ galaxies: stellar content ‐ cosmology: early Universe.