Collaborative Research: Understanding the Physics of Galaxy Clustering on Small Scales

该项目将测量、建模和解释10千秒差距到1兆秒差距尺度上的星系团-宇宙学背景下的小尺度。该项目包括四个主要科学目标。(1)限制星系在宇宙暗物质晕中的空间分布。利用斯隆数字巡天（SDSS）的红移数据，提议的团队将测量投影的两点相关函数，角相关函数以及星系群和星系团的表面密度分布。他们将利用从宇宙学N体模拟构建的解析模型和数值模型，对这些统计数据进行建模，以约束暗晕中星系的密度分布。(2)通过使用新的重子振荡光谱巡天（BOSS）的数据，将上述分析扩展到更高的红移。相关函数的模拟将揭示晕内星系空间分布的最新演化。(3)改进提议者关于合并影响下暗物质暗晕演化的半解析模型，改进质量损失的解析公式，并包括重子物质的作用。(4)通过比较改进的晕模型和聚类统计量，对合并较大晕的星系进行了星星形成和星星剥离效率的约束。该项目将支持两个合作机构的几名研究生和本科生的工作。此外，该项目将为夏季K-12科学营提供资金，以便田纳西州纳什维尔地区的少数民族学生能够在没有经济负担的情况下参加。

This project will measure, model, and interpret the clustering of galaxies on scales of 10 kiloparsecs to 1 megaparsec -- small scales in the cosmological context. The project consists of four main science goals. (1) Constrain the spatial distribution of galaxies inside dark matter halos in the local universe. Using redshift data from the Sloan Digital Sky Survey (SDSS), the proposing team will measure the projected two-point correlation function, the angular correlation function, and the surface density profile of galaxies in groups and clusters. They will model these statistics to constrain the density profile of galaxies in dark halos, using both analytic models and numerical models constructed from cosmological N-body simulations. (2) Extend the above analysis to higher redshift by using data from the new Baryon Oscillation Spectroscopic Survey (BOSS). Modeling the correlation functions will reveal the recent evolution in the spatial distribution of galaxies within halos. (3) Refine the proposers' semi-analytic model for the evolution of dark matter subhalos under the influence of merging, improving the analytic prescription for mass loss and including the role of baryonic matter. (4) By comparing the improved halo model to the clustering statistics, constrain the star formation and star stripping efficiencies for galaxies merging with larger halos. The project will support the work of several graduate and undergraduate students at the two collaborating institutions. In addition, the project will provide funding for summer K-12 science camps so that minority students in the Nashville, TN area will be able to attend without financial burden.