arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 2003.11557astro-ph.CO
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暗物质晕的相空间结构

The Phase Space Structure of Dark Matter Halos

Han Aung, Daisuke Nagai, Eduardo Rozo, Rafael Garcia

摘要:

暗物质晕的相空间结构可以用来测量晕的质量,推断质量吸积速率,并探测修正引力的影响。以往的研究表明,可以在位置空间中使用密度剖面的斜率来测量回溅半径。使用N体模拟,我们表明,相空间结构的暗物质晕不结束在这个溅回半径。相反,存在着一个区域,其中降落,回溅,和维里化晕空间混合。我们的三个运动学上不同的人口分布模型,并表明存在一个“边缘半径”,超过该半径的暗物质晕没有轨道子结构。这个半径是在以前的作品中定义的回溅半径的固定倍数,并且可以被解释为包含暗物质粒子的远心的固定分数的半径。我们的研究结果为Tomooka等人的论文中采用的卫星星系模型提供了坚实的理论基础,在那里我们分析了SDSS redMapPer团簇的相空间分布。

英文摘要:

The phase space structure of dark matter halos can be used to measure the mass of the halo, infer mass accretion rates, and probe the effects of modified gravity. Previous studies showed that the splashback radius can be measured in position space using the slope of the density profile. Using N-body simulations, we show that the phase space structure of the dark matter halo does not end at this splashback radius. Instead, there exists a region where infalling, splashback, and virialized halos are mixed spatially. We model the distribution of the three kinematically distinct populations and show that there exists an "edge radius" beyond which a dark matter halo has no orbiting substructures. This radius is a fixed multiple of the splashback radius as defined in previous works, and can be interpreted as a radius which contains a fixed fraction of the apocenters of dark matter particles. Our results provide a firm theoretical foundation to the satellite galaxy model adopted in the companion paper by Tomooka et al., where we analyzed the phase space distribution of SDSS redMaPPer clusters.

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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