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arXiv 1008.4103astro-ph.COastro-ph.GAhep-ph
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由内而外的暗物质晕

Dark Matter Halos from the Inside Out

James E. Taylor

摘要:

证据的平衡表明,单个星系和星系群或星系团嵌入在巨大的冷的,弱相互作用的暗物质分布中。这些暗物质“晕”为宇宙中所有发光结构提供了支架,它们的性质构成了当前宇宙学模型的重要组成部分。我回顾了暗物质晕的内部性质,着重于结构形成的数值模拟预测的简单,普遍的趋势。模拟表明,光环应该都具有大致相同的球平均密度分布和运动学结构,并预测在巨大的光环质量范围内以及所有常见变体的形状、形成历史和密度和运动学亚结构的简单分布。和谐宇宙学。我描述的观测进展,通过测量质量,形状,配置文件和子结构在真正的晕,使用重子示踪剂或引力透镜测试这些预测。模拟晕的一个重要性质(可能是最重要的性质)是它们的动力学“年龄”,或内部弛豫的程度。在决定重子物质的状态时,晕的年龄可能与其质量一样有影响,所以晕的年龄也值得尝试用观测方法来测量。我回顾了最近的引力透镜研究的星系团,应测量子结构和放松在一个大样本的个人集群晕,产生的定量措施的年龄,以及匹配的理论预测。从这些研究中推断出的年龄分布将导致宇宙学模型的第二代测试,以及对星系团组装和星系团内星系演化的更好理解。

英文摘要:

The balance of evidence indicates that individual galaxies and groups or clusters of galaxies are embedded in enormous distributions of cold, weakly interacting dark matter. These dark matter 'halos' provide the scaffolding for all luminous structure in the universe, and their properties comprise an essential part of the current cosmological model. I review the internal properties of dark matter halos, focussing on the simple, universal trends predicted by numerical simulations of structure formation. Simulations indicate that halos should all have roughly the same spherically-averaged density profile and kinematic structure, and predict simple distributions of shape, formation history and substructure in density and kinematics, over an enormous range of halo mass and for all common variants of the concordance cosmology. I describe observational progress towards testing these predictions by measuring masses, shapes, profiles and substructure in real halos, using baryonic tracers or gravitational lensing. An important property of simulated halos (possibly the most important property) is their dynamical 'age', or degree of internal relaxation. The age of a halo may have almost as much effect as its mass in determining the state of its baryonic contents, so halo ages are also worth trying to measure observationally. I review recent gravitational lensing studies of galaxy clusters which should measure substructure and relaxation in a large sample of individual cluster halos, producing quantitative measures of age that are well-matched to theoretical predictions. The age distributions inferred from these studies will lead to second-generation tests of the cosmological model, as well as an improved understanding of cluster assembly and the evolution of galaxies within 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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