arXiv 0809.09782008-09astro-ph

由LambdaCDM宇宙学模拟得到的星系晕及其红移演化

Galactic Halos Derived from LambdaCDM Cosmology Simulation and their Red-Shift Evolution

Hung-Yu Jian, Chia-Hung Chien, Tzihong Chiueh

备注：: 23 pages, 12 figures

摘要：

星系团可以在足够深的引力势中形成，从而发生有效的气体冷却。我们估计，这样的潜力是由质量晕$M \gtsim M_{c} \approx 7.0 \times 10^{12} ~ (Δ_{c}(z) (1+z)^{3})^{-1/2} \Msun$，其中$Δ_{c}(z)$是在红移$z$和$z = 0$的$M_{c} \approx 4.0 \times 10^{11} \Msun$形成的球形维里化对象的平均过密度。基于这一标准，我们的星系样本是从宇宙学模拟数据构建的，通过使用HiFOF选择那些FOF晕中的subhalos比$M_{c}$更大。暗暗晕的数量远远多于星系所在暗晕。对观测的几个测试已经进行了检查我们的星系样本，包括微分星系质量函数，星系空间密度，投影两点关联函数（CF），HOD，和运动对分数。这些测试显示出良好的一致性。基于与观测的一致性，我们的星系样本被认为是正确的代表星系在真实宇宙中，并可以用来研究其他未探索的星系性质。

英文摘要：

Galaxies can form in a sufficiently deep gravitational potential so that efficient gas cooling occurs. We estimate that such potential is provided by a halo of mass $M \gtsim M_{c} \approx 7.0 \times 10^{12} ~ (Δ_{c}(z) (1+z)^{3})^{-1/2} \Msun$, where $Δ_{c}(z)$ is the mean overdensity of spherically virialized objects formed at redshift $z$, and $M_{c} \approx 4.0 \times 10^{11} \Msun$ at $z = 0$. Based on this criterion, our galaxy samples are constructed from cosmology simulation data by using HiFOF to select subhalos in those FOF halos that are more massive than $M_{c}$. There are far more dark subhalos than galaxy-hosting subhalos. Several tests against observations have been performed to examine our galaxy samples, including the differential galaxy mass functions, the galaxy space density, the projected two point correlation functions (CF), the HODs, and the kinematic pair fractions. These tests show good agreements. Based on the consistency with observations, our galaxy sample is believed to correctly represent galaxies in real universe, and can be used to study other unexplored galaxy properties.

机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。

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英文摘要：

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