Galaxies and the Intergalactic Medium at z=1.5-3.5

这个项目包括几个相关的观测项目，以研究在1.5到3.5红移范围内的星系和弥散星系间介质的性质、大规模分布和演化，以及两者之间的关系，在那里，新的观测技术和设施首次提供了对这个几乎未被探索的时代的大规模访问。其目的是在星系和黑洞生长最重要的时期，尽可能完整地汇编出重子宇宙的图像。利用互补星系调查和高质量的类星体吸收谱线光谱将揭示恒星形成星系和星系间气体之间的相互作用，并使吸收系统、AGN活动和星系形成和演化的环境依赖性研究成为可能。决定星系间弥漫介质特性的所有电离光子源都将被探测和量化。深光学和近红外光谱将在星系群中建立物理条件和趋势。一些观测到的场将通过使用多个类星体的视线，在相同的宇宙体积中补充关于星系间介质的独特信息。在其他领域，公开可用的多波长和天基数据将与新的观测相结合，研究星系与活动星系核之间的联系。该项目获得的关于早期星系和星系间介质的基本统计信息将对天文学许多子领域的研究人员有用，所有的结果和数据将向社区提供。对宇宙历史的兴趣对大多数人来说是很自然的，可以引发科学家之间的讨论，甚至是最害怕科学的外行人。PI最近获得的麦克阿瑟奖学金提供了一个不同寻常的机会，通过由此增加的知名度来接触更多的受众，并且应该有很多机会向非科学家传达科学和科学事业的兴奋。

AST-0307263SteidelThis project comprises several related observational programs to study the nature, large-scale distribution, and evolution of galaxies and of the diffuse intergalactic medium, and the relationship between the two, over the redshift range from 1.5 to 3.5, where new observational techniques and facilities are providing the first wholesale access to this almost unexplored era. The intent is to compile as complete as possible a picture of the baryonic universe during the most important era for galaxy and black hole growth. Using complementary galaxy surveys and high quality quasar absorption line spectroscopy will reveal the interactions between star-forming galaxies and intergalactic gas, and enable a study of the environment dependence of absorption systems, AGN activity, and galaxy formation and evolution. All sources of the ionizing photons that dictate the properties of the diffuse intergalactic medium will be detected and quantified. Deep optical and near-infrared spectroscopy will establish physical conditions and trends amongst the galaxy population. Some of the observed fields will be supplemented by unique information on the intergalactic medium in the same cosmic volumes, using multiple quasar lines of sight. In other fields, publicly available multi-wavelength and space-based data will be combined with the new observations to study the connection between galaxies and active galactic nuclei.The fundamental statistical information on early galaxies and the intergalactic medium obtained by this project will be useful to researchers in many sub-fields of astronomy, and all of the results and data will be made available to the community. An interest in the history of the Universe comes naturally to most people and can spark discussion between scientists and even the most science-phobic lay person. The PI's recent MacArthur fellowship provides an unusual opportunity to reach a larger audience through the resultant increased visibility, and there should be many chances to communicate the excitement of science and the scientific enterprise to nonscientists.