Intergalactic Metals at Very High Redshift

星际气体中的金属是我们在早期宇宙中形成恒星的主要制约因素之一，也是形成星系反馈和改变其环境的过程的主要制约因素之一，但对金属的解释很复杂。研究星际金属的主要目标之一是限制最早的恒星形成，这使得尽可能早地追溯金属变得重要。该项目将对红移4到6之间的已知最亮类星体进行尽可能高的信噪比观测，以确定星系间离子的分布到可能最深的水平。在凯克10米望远镜上安装的新的HiRes光谱仪具有出色的红色灵敏度和宽波长覆盖范围，为本研究提供了最佳的可用光谱。在首席研究员之前的NSF奖下开发的最佳分析技术然后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模型产生广泛的影响。金属丰度导数和光谱都将提供给理论家和对恒星和星系形成进行数值模拟的小组。研究成果将通过公众可访问的网页和讲座进行传播。与以往的赠款一样，研究生支助将侧重于培训妇女，特别是亚裔妇女，以协助在这些社区培养一支女天文学家队伍。

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.