Observed versus modelled u-, g-, r-, i-, z-band photometry of local galaxies – evaluation of model performance
Observed versus modelled u-, g-, r-, i-, z-band photometry of local galaxies – evaluation of model performance
复制标题
DOI：
10.1111/j.1365-2966.2012.21659.x
复制
发表时间：
2012-07
影响因子：
4.8
通讯作者：
K. Hansson;T. Lisker;E. Grebel
中科院分区：
文献类型：
--
作者：
K. Hansson;T. Lisker;E. Grebel
我们测试了现有的恒星群模型如何很好地再现斯隆数字天空调查所探索的本地星系群(0.02≤z≤0.03)的u、g、r、i、z波段光度测量。我们的研究是从模型使用者的角度进行的，他们手头有观测数据，并试图将它们转换为物理量。星系的恒星种群模型是通过合成恒星形成历史和使用来自几个群(Starburst99，Galaxev，Maraston模型，Galev)的单个恒星种群的化学富集物来创建的。尘埃的作用是通过一个简单的、但受观测激励的尘埃模型来解决的，该模型将消光的幅度与恒星形成历史、金属丰度和视角联系在一起。此外，还考虑了发射线的影响(对于包含该组件的模型子集)。通过(1)使用(u−g)-(r−i)和(g−r)-(i−z)色面将它们的预测与SDSS中观测到的星系总数进行比较，(2)将预测的恒星质量和光度加权年龄和金属度、比恒星形成率、质量光比和总消光比与基于光谱学研究的文献值进行比较。不同的模型之间有很大的差异，有几个模型占据了颜色-颜色图中没有观测到星系的区域。因此，我们要强调选择模式的重要性。使用我们首选的模型，我们发现，通过使用u、g、r、i、z波段光度测量，可以在参数空间的很大一部分范围内约束恒星形成历史、金属丰度和尘埃含量。然而，由于在颜色空间的某些部分具有高消光和低消光的模型的重叠，存在强烈的局部简并。
We test how well available stellar population models can reproduce observed u-, g-, r-, i-, z-band photometry of the local galaxy population (0.02 ≤ z ≤ 0.03) as probed by the Sloan Digital Sky Survey (SDSS). Our study is conducted from the perspective of a user of the models, who has observational data in hand and seeks to convert them into physical quantities. Stellar population models for galaxies are created by synthesizing star formation histories and chemical enrichments using single stellar populations from several groups (starburst99, galaxev, the Maraston models, galev). The role of dust is addressed through a simplistic, but observationally motivated, dust model that couples the amplitude of the extinction to the star formation history, metallicity and the viewing angle. Moreover, the influence of emission lines is considered (for the subset of models for which this component is included). The performance of the models is investigated by (1) comparing their prediction with the observed galaxy population in the SDSS using the (u − g)–(r − i) and (g − r)–(i − z) colour planes, (2) comparing predicted stellar mass and luminosity weighted ages and metallicities, specific star formation rates, mass-to-light ratios and total extinctions with literature values from studies based on spectroscopy. Strong differences between the various models are seen with several models occupying regions in the colour–colour diagrams where no galaxies are observed. We would therefore like to emphasize the importance of the choice of model. Using our preferred model we find that the star formation history, metallicity and also dust content can be constrained over a large part of the parameter space through the use of u-, g-, r-, i-, z-band photometry. However, strong local degeneracies are present due to overlap of models with high and low extinction in certain parts of the colour space.