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arXiv 2101.05280astro-ph.GA
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质量以外晕性质的观测测量

Observational Measures of Halo Properties Beyond Mass

Peter Behroozi, Andrew Hearin, Benjamin P. Moster

摘要:

暗物质晕的不同性质,包括生长速率、浓度、相互作用历史和自旋,以独特的、依赖于尺度的方式与环境相关。虽然这些晕的性质不能直接观察到,但星系将继承它们的宿主晕与环境的相关性。在本文中,我们将展示这些特征的环境签名如何允许使用星系环境的测量来约束哪些暗物质晕属性与可观测到的星系属性最紧密相关。我们发现,除了质量之外,不同的晕属性在星系两点关联函数和星系$k$ th最近邻的距离分布中都留下了不同的尺度依赖特征,这些特征足够强大,即使在低分辨率下也可以访问(例如,棱镜)光谱。作为一个应用,我们计算了观测到的两点关联函数的星系分仓的半质量半径在$z=0$从斯隆数字巡天,表明经典的星系大小模型(即,星系大小与晕旋成正比)以及最近的其他提议都显示出与观测数据之间的严重矛盾。我们发现,与观察到的集群的协议,可以提高一个简单的经验模型,星系大小与晕生长。

英文摘要:

Different properties of dark matter haloes, including growth rate, concentration, interaction history, and spin, correlate with environment in unique, scale-dependent ways. While these halo properties are not directly observable, galaxies will inherit their host haloes' correlations with environment. In this paper, we show how these characteristic environmental signatures allow using measurements of galaxy environment to constrain which dark matter halo properties are most tightly connected to observable galaxy properties. We show that different halo properties beyond mass imprint distinct scale-dependent signatures in both the galaxy two-point correlation function and the distribution of distances to galaxies' $k$th nearest neighbours, with features strong enough to be accessible even with low-resolution (e.g., grism) spectroscopy at higher redshifts. As an application, we compute observed two-point correlation functions for galaxies binned by half-mass radius at $z=0$ from the Sloan Digital Sky Survey, showing that classic galaxy size models (i.e., galaxy size being proportional to halo spin) as well as other recent proposals show significant tensions with observational data. We show that the agreement with observed clustering can be improved with a simple empirical model in which galaxy size correlates with halo growth.

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