Intergalactic Metals at Very High Redshift

星系间气体中的金属是我们对早期宇宙中恒星形成的主要限制之一，也是对形成星系反馈并改变其环境的过程的主要限制之一，但是对金属的解释是复杂的。研究星系间金属的主要目标之一是限制最早的恒星形成，这使得尽可能追溯金属变得很重要。这个项目将获得红移4到6之间最亮的已知类星体的最高可能的信噪比观测，以确定星系间离子在尽可能深的水平上的分布。Keck 10米望远镜上的新HIRES光谱仪具有出色的红色灵敏度和较宽的波长覆盖范围，为本研究提供了最佳的可用光谱。在首席研究员之前的NSF奖励下开发的最佳分析技术可以用来测量这些高红移的离子密度、分布和电离。这些结果将对物理宇宙学和第一批恒星和星系形成的理论建模产生广泛的影响。金属丰度衍生和光谱都将提供给理论家和进行恒星和星系形成数值模拟的团体。研究成果将通过网页和讲座向公众传播。与以前的资助一样，研究生资助将强调培训妇女，特别是亚洲妇女，以协助在这些社区发展女性天文学家骨干队伍。

AST-0607871CowieThe metals in the intergalactic gas are one of our primary constraints on star formation in the early Universe, and on the processes by which forming galaxies feed back into and modify their environments, but interpretation of the metals is complex. One of the principal goals of studying intergalactic metals is to put limits on the earliest star formation, making it important to trace the metals as far back as possible. This project will obtain the highest possible signal-to-noise observations of the brightest known quasars between redshifts four and six, to determine the distributions of intergalactic ions to the deepest possible level. The new HIRES spectrograph implementation on the Keck 10-meter telescope has outstanding red sensitivity and wide wavelength coverage, providing the best available spectra for this study. Optimal analysis techniques developed under the principal investigator's previous NSF award can then be used to measure the ion densities, distributions, and ionizations at these high redshifts.These results will have a broad impact on physical cosmology and theoretical modeling of the formation of the first stars and galaxies. Both the metallicity derivations and the spectra will be made available to theorists and to groups undertaking numerical simulations of star and galaxy formation. Research results will be spread through web pages and talks accessible to the general public. As with previous grants, graduate student support will emphasize the training of women, particularly Asian women, to assist in developing a cadre of women astronomers in these communities.