论文标题
暗物质光环之间成对速度分布的半分析模型
A semi-analytic model of pairwise velocity distribution between dark matter halos
论文作者
论文摘要
我们研究了两个不同的暗物质光环（即成对速度）之间使用一组高分辨率宇宙学$ n $ body仿真之间相对速度的概率分布函数（PDF）。我们在$ 10^{12.5-15} \，h^{ - 1} m _ {\ odot} $和$ 0 <z <1 $的红移。在给定的一组质量，红移和两个光晕之间的分离长度，我们的模型需要三个参数来设置成对速度PDF，而文献中先前的非高斯模型则假设四个或更多自由参数。在$ r = 5-40 \的长度尺度上，[h^{ - 1} \，\ mathrm {mpc}] $，我们的模型预测了黑物质卤素对黑物质的平均值和分散，其质量为$ 10^{12.5-13.5} \，[h^h^，[h^$ 10} $0。在模拟中，对于其他质量和仿真中探索的其他质量和红移，模型的精度为5％，而模型的精度达到20％（主要是10％的水平）。我们证明，我们的成对速度PDF模型在$ O（10）\，H^{ - 1} \ Mathrm {MPC} $之间的尺度上的大规模 - 半混合大小的光环的两点聚类提供了准确的映射。对于质量限制的光环样品，其质量大于$ 10^{13.5} \，h^{ - 1} m _ {\ odot} $ at $ z = 0.55 $，我们的模型可以解释与红色速度空间的两点相关的单极和二极管矩，与5％的$ 5- $ 5-40 $和$ 5-40 s s sales $ and $ 5- 4 h^{ - 1} \ mathrm {mpc} $。我们的成对速度PDF的模型将在红移调查中对大型星系的大规模星系的统计数据提供详细的解释，包括在两点相关功能中的非线性红移空间失真效应以及动力学Sunyaev-Sunyaev-Zel'dovich效应的测量。
We study the probability distribution function (PDF) of relative velocity between two different dark matter halos (i.e. pairwise velocity) with a set of high-resolution cosmological $N$-body simulations. We investigate the pairwise velocity PDFs over a wide range of halo masses of $10^{12.5-15}\, h^{-1}M_{\odot}$ and redshifts of $0<z<1$. At a given set of masses, redshift and the separation length between two halos, our model requires three parameters to set the pairwise velocity PDF, whereas previous non-Gaussian models in the literature assume four or more free parameters. At the length scales of $r=5-40\, [h^{-1}\, \mathrm{Mpc}]$, our model predicts the mean and dispersion of the pairwise velocity for dark matter halos with their masses of $10^{12.5-13.5} \, [h^{-1}M_{\odot}]$ at $0.3 < z < 1$ with a 5%-level precision, while the model precision reaches a 20% level (mostly a 10% level) for other masses and redshifts explored in the simulations. We demonstrate that our model of the pairwise velocity PDF provides an accurate mapping of the two-point clustering of massive-galaxy-sized halos at the scales of $O(10)\, h^{-1}\mathrm{Mpc}$ between redshift and real space for a given real-space correlation function. For a mass-limited halo sample with their masses greater than $10^{13.5}\, h^{-1}M_{\odot}$ at $z=0.55$, our model can explain the monopole and quadropole moments of the redshift-space two-point correlations with a precision better than 5% at the scales of $5-40$ and $10-30\, h^{-1}\mathrm{Mpc}$, respectively. Our model of the pairwise velocity PDF will give a detailed explanation of statistics of massive galaxies at the intermediate scales in redshift surveys, including the non-linear redshift-space distortion effect in two-point correlation functions and the measurements of the kinematic Sunyaev-Zel'dovich effect.
