Semianalytical Model of Galaxy Formation with High-Resolution N-Body Simulations
Semianalytical Model of Galaxy Formation with High-Resolution N-Body Simulations
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DOI：
10.1086/432493
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发表时间：
2004-08
期刊：
影响因子：
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通讯作者：
X. Kang;X. Kang;Y. Jing;H. Mo;G. Börner
中科院分区：
文献类型：
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作者：
X. Kang;X. Kang;Y. Jing;H. Mo;G. Börner
我们在一系列高分辨率的N体模拟模型的星系形成的半解析方法。不像许多早期的调查的基础上半解析模型，我们利用的subhalos解决的N体模拟遵循合并的星系在黑暗的晕，我们表明，这是关键的正确建模的星系光度函数在明亮的一端和双峰性质的星系颜色分布。以暗晕为基础的星系合并也会在高z处产生更多明亮的红色星系。我们采用的半解析模型是类似于早期的半解析研究中使用的，除了我们认为在小晕长时间冷却的效果，我们明确遵循星际介质中的化学富集。我们使用我们的模型来预测低红移时星系群的特性，并将其与当前的各种观测结果进行比较。我们发现，我们的模型预测可以匹配的光度函数的星系在各种波段红比u带。如果用暗晕的合并树来模拟星系合并，则亮端的光度函数的形状可以很好地再现，如果低质量晕中的气体冷却时间与宇宙的年龄相当，则陡峭的暗端斜率可以缓和。该模型与subhalos解决可以重现的主要功能，在观察到的颜色双峰分布，虽然它仍然预测太多的明亮的蓝色星系。同样的模型也可以拟合星系团中椭圆星系的色-星等关系、旋涡星系的金属度-光度关系和金属度-自转速度关系以及现今旋涡星系的气体分数。我们还确定了模型需要进一步改进的地方。
We model the galaxy formation in a series of high-resolution N-body simulations using the semianalytical approach. Unlike many earlier investigations based on semianalytical models, we make use of the subhalos resolved in the N-body simulations to follow the mergers of galaxies in dark halos, and we show that this is pivotal in modeling correctly the galaxy luminosity function at the bright end and the bimodal nature of galaxy color distribution. Mergers of galaxies based on subhalos also result in many more bright red galaxies at high z. The semianalytical model we adopt is similar to those used in earlier semianalytical studies, except that we consider the effect of a prolonged cooling in small halos and that we explicitly follow the chemical enrichment in the interstellar medium. We use our model to make predictions for the properties of the galaxy population at low redshift and compare them with various current observations. We find that our model predictions can match the luminosity functions of galaxies in various wavebands redder than the u band. The shape of the luminosity function at the bright end is well reproduced if galaxy mergers are modeled with the merger trees of subhalos, and the steep faint-end slope can be moderated if the gas cooling time in low-mass halos is comparable to the age of the universe. The model with subhalos resolved can reproduce the main features in the observed color bimodal distribution, although it still predicts too many bright blue galaxies. The same model can also match the color-magnitude relation for elliptical galaxies in clusters, the metallicity-luminosity relation and metallicity-rotation velocity relation of spiral galaxies, and the gas fraction in present-day spiral galaxies. We also identify areas where further improvements of the model are required.