Collaborative Research: Halo Modeling Strikes Back: New Techniques to infer the Galaxy-Dark Matter Connection in the Presence of Environmental Effects

在接下来的十年里，一些创新的望远镜观测将为科学家提供丰富的关于星系和宇宙学的精确数据。该项目旨在消除最近发现的星系和暗物质之间关系模型中的缺陷，这是解释星系调查数据所必需的。研究人员将开发并公开一个开源软件包，用于将解释星系数据集时的系统误差降至最低，从而更好地理解星系的形成和演化，并为在精密宇宙学中公正地使用星系调查铺平道路。作为对这一新的研究计划的补充，这项建议包括对K-12科学教育的贡献，满足学生从事STEM相关学科的迫切需求。在耶鲁大学，Pi van den Bosch将为莱特纳家庭天文台和天文馆制作一场以重力为主题的定制天文表演，为八年级学生量身定做。在匹兹堡大学，PiZentner将担任Buhl Academy的讲师，这是卡内基科学中心Buhl天文馆的一个新项目，将科学家与匹兹堡地区的K-12教师配对。光晕职业建模对星系和暗物质光晕之间的概率关系进行建模，是解释星系团的主要工具。在所有的晕占领研究中，一个标准的假设是，暗物质晕的质量完全决定了它所在星系群的性质。越来越多的观测证据表明，星系的性质，特别是恒星形成率，与晕的性质有关，而不是与质量有关，如晕的年龄或浓度。无论是在理解星系演化的努力中，还是在精密宇宙学计划中，这种“星系组装偏差”(GAB)都是系统误差的一个重要来源。为了确保对即将到来的数据的不偏不倚的解释，本提案旨在开发能够适当解释GAB的下一代光晕占领模型。研究人员将确定可用于推断GAB的存在和强度的最佳观测诊断集，开发适当解释GAB的开源软件，并探索通过使用对晕质量的替代定义来减轻GAB影响的方法。他们将把这些新开发的技术应用于现有的星系调查数据，并对即将到来的调查如DES、EBOSS、DESI、LSST、Euclid和WFIRST进行预测。

In the next decade, a number of innovative telescopic surveys will provide scientists with a wealth of precise data regarding galaxies and cosmology. This project aims to remove recently identified deficiencies in models of the relationship between galaxies and dark matter, necessary to interpret galaxy survey data. The researchers will develop, and make publicly available, an open-source software package that could be used to minimize systematic errors in interpreting galaxy data sets, leading to a better understanding of galaxy formation and evolution, and also paving the way for unbiased use of galaxy surveys in precision cosmology. Complementing this novel research program, this proposal includes contributions to K-12 science education, addressing the critical need for students to engage in STEM-related disciplines. At Yale, PI van den Bosch will develop a custom planetarium show for the Leitner Family Observatory and Planetarium on the topic of gravity, and tailored to 8th graders. At the University of Pittsburgh, PI Zentner will serve as an instructor in the Buhl Academy, a new program at the Carnegie Science Center Buhl Planetarium that pairs scientists with Pittsburgh area K-12 teachers.Halo occupation modeling models the probabilistic relation between galaxies and dark matter halos and is the premier tool for interpreting the clustering of galaxies. A standard assumption made in all halo occupation studies is that the mass of a dark matter halo completely determines the properties of its resident galaxy population. Mounting observational evidence indicates that galaxy properties, in particular star formation rates, are correlated with halo properties other than mass, such as halo age or concentration. This "galaxy assembly bias" (GAB) is a significant source of systematic error, both in efforts to understand galaxy evolution and in the precision cosmology program. In order to ensure the unbiased interpretation of forthcoming data, this proposal aims to develop the next generation halo occupation models that properly account for GAB. The researchers will identify the optimal set of observational diagnostics that can be used to infer the presence and strength of GAB, develop open-source software that properly accounts for GAB, and explore methods to mitigate the impacts of GAB by using alternative definitions of halo mass. They will apply these newly developed techniques to extant galaxy survey data, and make predictions for forthcoming surveys such as DES, eBOSS, DESI, LSST, EUCLID, and WFIRST.