From Galaxy Clustering to Galaxy Formation and Evolution

该奖项由2009年美国复苏和再投资法案(公法111-5)资助。泽哈维博士将在斯隆数字巡天(SDSS)等大型调查中分析和模拟星系的聚集，以探索星系的形成和宇宙大尺度结构的发展。她和其他人已经证明，在小尺度上，暗淡的红色星系比明亮的星系聚集得更紧密。如果暗星系是更明亮的星系的卫星，共享它们巨大的黑暗光晕，这就可以解释。Zehavi博士和她的团队将通过检查来自SDSS的更大样本来检验这一假设，并将暗红色星系的星系团属性与通过引力N体模拟预测的卫星暗晕的星系团属性进行比较。SDSS数据还将用于检查卫星星系的分布，将观测到的各向异性分布与目前卫星在宇宙网中形成丝状结构的模型的预测进行比较。她将使用其他对更遥远的星系的调查，来研究在过去100亿年的宇宙历史中，星系团是如何变化的。要做到这一点，泽哈维博士将构建一个晕占据分布模型，该模型给出了星系在给定时间的光度和外观与其暗晕质量之间的统计关系。暗晕的增长可以在宇宙N体模拟中得到跟踪，因此这个模型将在现在的星系和数十亿年前的可能的前兆之间提供联系。参与研究的博士后学者将接受培训；本科生也将参与其中。泽哈维博士将继续在当地进行公众宣传讲座。她将与当地一家博物馆和天文馆合作开发展品，并指导作为博物馆实习生的本科生。

This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5).Dr Zehavi will analyze and model the clustering of galaxies in large surveys such as the Sloan Digital Sky Survey (SDSS), to probe galaxy formation and the development of cosmic large-scale structure. She and others have shown that on small scales, dim red galaxies are more strongly clustered than brighter ones. This could be explained if the dim galaxies are satellites of more luminous galaxies, sharing their massive dark halos. Dr Zehavi and her team will test this hypothesis by examining much larger samples from the SDSS, and comparing the clustering properties of the dim red galaxies to those predicted for satellite dark halos by gravitational N-body simulations. The SDSS data will also be used to examine the distribution of satellite galaxies, comparing the observed anisotropic distribution with predictions from current models in which the satellites form in filaments of the cosmic web. She will use other surveys of more distant galaxies to examine how galaxy clustering has changed over the past 10 billion years of cosmic history. To do this, Dr Zehavi will construct a Halo Occupation Distribution model, which gives a statistical relation between the luminosity and appearance of a galaxy at a given time and the mass of its dark halo. The growth of dark halos can be followed in cosmological N-body simulations, so this model will provide a link between present-day galaxies and their probable precursors, billions of years earlier.A postdoctoral scholar will be trained by participating in the research; undergraduate students will also be involved. Dr Zehavi will continue to give public-outreach talks at local venues. She will partner with a local museum and planetarium to develop exhibits, and mentor undergraduates working as museum interns.