arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 2011.08840astro-ph.COastro-ph.GA
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在宇宙网中捕获:环境对晕浓度、形状和自旋的影响

Caught in the cosmic web: Environmental effect on halo concentrations, shape, and spin

Wojciech A. Hellwing, Marius Cautun, Rien van de Weygaert, Bernard T. Jones

摘要:

利用一组高分辨率的模拟,我们研究了暗物质晕特性与大尺度环境的统计相关性。我们认为晕人口分为四个宇宙网络(CW)的元素:空隙,墙壁,细丝,和节点。我们第一次提出了一个研究连续波效应的晕覆盖六十年的质量:$10^{8}-10^{14}{h^{-1}{\rm M}_{\odot}}$。我们发现,晕生活在各种网络组件的分数是一个强大的功能的质量,与大多数的$M>10^{12}{h^{-1}{\rm M}_{\odot}}$晕生活在细丝和节点。低质量晕更均匀地分布在细丝、壁和空隙中。对于晕密度分布和形成时间,我们发现一个通用的质量阈值$M_{th}\sim6\times10^{10}{h^{-1}{\rm M}_{\odot}}$以下,这些属性随环境而变化。在这里,细丝晕有最陡的浓度-质量关系,壁接近整体平均值,而空洞晕有最平坦的关系。这相当于$c_{200}$的细丝和空隙晕,分别是$14\%$高于和$7\%$低于平均值在$M=2\times10^8{h^{-1}{\rm M}_{\odot}}$,与低质量的节点晕是最有可能飞溅回来。我们发现双幂律拟合,很好地描述了$c(M)$的四个环境中的整个探测质量范围。一个互补的图片被发现的平均形成时间,与质量形成时间的关系以下的趋势所示的浓度:节点晕是最古老的和空晕最年轻的。在研究晕的自旋和形状时,CW环境效应要弱得多。晕质量的趋势相反:$M<10^{10}{h^{-1}{\rm M}_{\odot}}$的小晕似乎不受CW环境的影响。对于更大质量的空洞和壁晕,可以看到一些微弱的趋势,平均而言,其特征在于较低的自旋和较高的三轴度参数。

英文摘要:

Using a set of high-resolution simulations we study the statistical correlation of dark matter halo properties with the large-scale environment. We consider halo populations split into four Cosmic Web (CW) elements: voids, walls, filaments, and nodes. For the first time we present a study of CW effects for halos covering six decades in mass: $10^{8}-10^{14}{h^{-1}{\rm M}_{\odot}}$. We find that the fraction of halos living in various web components is a strong function of mass, with the majority of $M>10^{12}{h^{-1}{\rm M}_{\odot}}$ halos living in filaments and nodes. Low mass halos are more equitably distributed in filaments, walls, and voids. For halo density profiles and formation times we find a universal mass threshold of $M_{th}\sim6\times10^{10}{h^{-1}{\rm M}_{\odot}}$ below which these properties vary with environment. Here, filament halos have the steepest concentration-mass relation, walls are close to the overall mean, and void halos have the flattest relation. This amounts to $c_{200}$ for filament and void halos that are respectively $14\%$ higher and $7\%$ lower than the mean at $M=2\times10^8{h^{-1}{\rm M}_{\odot}}$, with low-mass node halos being most likely splashed-back. We find double power-law fits that very well describe $c(M)$ for the four environments in the whole probed mass range. A complementary picture is found for the average formation times, with the mass-formation time relations following trends shown for the concentrations: the nodes halos being the oldest and void halo the youngest. The CW environmental effect is much weaker when studying the halo spin and shapes. The trends with halo mass is reversed: the small halos with $M<10^{10}{h^{-1}{\rm M}_{\odot}}$ seem to be unaffected by the CW environment. Some weak trends are visible for more massive void and walls halos, which, on average, are characterized by lower spin and higher triaxiality parameters.

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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