标题： 暗物质晕的密度分布和聚集性 显示英文标题

标题： Density profiles and clustering of dark matter halos

摘要： 暗物质（DM）晕的密度分布和聚集特性是理解许多星系观测的重要组成部分。 在本次报告中，我将展示我们从大量高质量的N体模拟中得到的这两个量的新结果。 我们表明，在爱因斯坦-德西特宇宙中，大约35%的晕无法用Navarro、Frenk和White（NFW）分布来拟合，这是由于次结构过于显著，另外50%的晕次结构较少，可以用NFW分布合理描述，其余次结构最少的晕可以非常完美地用NFW分布来拟合。 对于那些可以合理或更好拟合NFW分布的晕，浓度参数$c$的概率分布函数可以用一个具有分散度$\sigma=0.27$的对数正态函数很好地描述。 $c$的平均值与NFW预测的非常接近，尽管随着次结构的增加而减小。 我们的聚集分析显示，低质量晕的聚集程度明显强于Mo和White的预测。 因此，提出了一种两两点相关函数的公式，可以非常准确地拟合我们的模拟结果（包括CDM模型和无尺度聚集模型）。 显示英文摘要

摘要： The density profile and the clustering of dark matter (DM) halos are two very important ingredients for understanding many observations of galaxies. In this talk, I present our new results for these two quantities from a large set of high quality N-body simulations. We show that in an Einstein de Sitter Universe about 35 percent of the halos could not be fitted by the Navarro, Frenk & White (NFW) profile because of too significant substructures, another 50 percent with less substructures can be reasonably described by the NFW profile, and the rest with the least substructures can be fitted by the NFW profile very nicely. For the halos which can be reasonably or better fitted by the NFW profile, the probability distribution function of the concentration parameter $c$ could be well described by a lognormal function with a dispersion $\sigma=0.27$. The mean value of $c$ is quite close to that predicted by NFW, though it decreases with the increase of the substructures. Our clustering analysis shows a significantly stronger clustering for low mass halos than Mo & White predict. A formula is therefore presented for the two-point correlation function of halos which can fit our simulation results (both CDM models and scale-free clustering models) very accurately.