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arXiv 0902.3433astro-ph.GAastro-ph.CO
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星系形成在暗物质晕结构和动力学中的作用

The role of galaxy formation in the structure and dynamics of dark matter halos

Chiara Tonini

摘要:

由层次聚类方案预测的暗物质晕的结构和动力学与从星系尺度的观测中推断的性质不一致。我的论文通过采取进化的方法来解决这个问题。我详细分析了许多不同的观测证据,这些证据表明,预言的晕平衡态与根据盘星系的可测量性质推断的晕之间存在差异,以及亮暗成分的角动量、几何形状和质量分布之间存在的标度关系。我意识到,它们似乎都指向同一个结论:在晕内的重子通过坍缩和聚集形成星系,扰动了晕的平衡结构,使其演化为新的构型。从理论的观点来看,暗物质晕作为无碰撞的粒子系统的行为使得它们的平衡结构和质量分布对它们内部动力学的扰动极其敏感。发生在晕内的星系形成是一个巨大的事件,在原星系坍缩过程中,重子和暗物质之间的动力学耦合代表了晕动力学结构的扰动,大到足以触发晕演化,根据两个组件的相对质量和角动量。我的结论是,暗物质晕的结构和动力学,以及晕和星系性质之间的联系的起源,是要理解的重子和暗成分的联合演化,起源于星系的崩溃和形成的时代。

英文摘要:

The structure and dynamics of dark matter halos, as predicted by the hierarchical clustering scenario, are at odds with the properties inferred from the observations at galactic scales. My Thesis addresses this problem by taking an evolutionary approach. I analysed in detail the many and different observational evidences of a discrepancy the predicted halo equilibrium state and the one inferred from the measurable properties of disk galaxies, as well as of the scaling relations existing between the angular momentum, geometry and mass distribution of the luminous and dark components, and realized that they all seem to point towards the same conclusion: the baryons hosted inside the halo, by collapsing and assembling to form the galaxy, perturb the halo equilibrium structure and made it evolve into new configurations. From the theoretical point of view, the behaviour of dark matter halos as collisionless systems of particles makes their equilibrium structure and mass distribution extremely sensitive to perturbations of their inner dynamics. The galaxy formation occurring inside the halos is a tremendous event, and the dynamical coupling between the baryons and the dark matter during the protogalaxy collapse represents a perturbation of the halo dynamical structure large enough to trigger a halo evolution, according to the relative mass and angular momentum of the two components. My conclusion is that the structure and dynamics of dark matter halos, as well as the origin of the connection between the halo and galaxy properties, are to be understood in in terms of a joint evolution of the baryonic and dark components, originating at the epoch of the collapse and formation of the galaxy.

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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