The Interpretation of Galaxy Clustering

AST-0707985温伯格对巨大星系样本的成像和光谱调查，最著名的是斯隆数字巡天（SDSS），已经改变了对大尺度结构的研究，但解释的挑战是，可观察到的星系聚集反映了暗物质聚集和星系与暗物质之间潜在的复杂偏差效应。 Halo Occupation Distribution（HOD）框架通过在维里化暗物质晕的水平上描述星系偏差来解决这一挑战，主要是通过特定质量的晕包含特定类别的给定数量的星系的概率。 该项目包括理论和观测研究，将进一步发展HOD方法，并将其应用于SDSS的测量。 理论工作将揭示环境变化对HOD的影响，例如暗物质晕的星系含量对大尺度密度场的系统依赖性。 观测工作是对最终SDSS星系红移巡天的连贯分析和解释，利用相关函数，群多重性，红移空间扭曲，空概率，星系-星系透镜，群质量测定和大尺度星系功率谱。 这种分析将产生许多不同类别的星系的HOD测定，和宇宙学参数的约束，更严格，更好地测试比传统获得。 它将为星系的形成、暴胀的物理学、宇宙的物质含量以及暗能量的性质提供新的线索。 该项目包括一些关于星团-星系透镜的工作，作为探测波动增长和宇宙距离尺度演变的工具。首席研究员担任SDSS的发言人，负责促进SDSS合作的科学互动和生产力，并向天文学界和公众推广SDSS。 这项研究为这些活动提供了间接但至关重要的支持，从而提高了SDSS的科学回报及其在教育和公共宣传方面的作用。 该项目还支持研究生培训和在各种论坛上公开介绍天文学。

AST-0707985WeinbergImaging and spectroscopic surveys of enormous galaxy samples, most notably the Sloan Digital Sky Survey (SDSS), have transformed the study of large scale structure, but the challenge of interpretation is that observable galaxy clustering reflects both dark matter clustering and the potentially complex bias effect between galaxies and dark matter. The Halo Occupation Distribution (HOD) framework addresses this challenge by describing galaxy bias at the level of virialized dark matter halos, principally via the probability that a halo of a specified mass contains a given number of galaxies of a specified class. This project includes theoretical and observational investigations that will further develop HOD methods and apply them to measurements from the SDSS. The theoretical work will reveal the effect of environmental variations on the HOD, such as a systematic dependence of the galaxy content of dark matter halos on the large scale density field. The observational work is a coherent analysis and interpretation of the final SDSS galaxy redshift survey, drawing on correlation functions, group multiplicities, redshift-space distortions, void probabilities, galaxy-galaxy lensing, group mass determinations, and the large scale galaxy power spectrum. This analysis will yield HOD determinations of many different classes of galaxies, and cosmological parameter constraints that are tighter and better tested than traditionally obtained. It will shed new light on galaxy formation, the physics of inflation, the matter content of the Universe, and the nature of dark energy. The project includes some work on cluster-galaxy lensing as a tool for probing the growth of fluctuations and the evolution of the cosmic distance scale.The Principal Investigator serves as Spokesperson for the SDSS, responsible for fostering the scientific interaction and productivity of the SDSS collaboration and for promoting the SDSS to the astronomical community and the general public. This research provides indirect but crucial support to such activities, thus enhancing the scientific return from the SDSS and its role in education and public outreach. The project also supports graduate student training and the public presentation of astronomy in various forums.