Galaxies in the Reionization Era

见证第一个星系的形成是星系外天体物理学的关键目标之一。天文学家希望了解星系最初是什么时候出现的，什么物理过程调节了它们的早期演化，以及它们的恒星形成在多大程度上推动了宇宙的后续演化。这项由美国国家科学基金会资助的研究将从根本上解决长期存在的关于宇宙最初10亿年构成的问题，并将为未来地面和太空望远镜的研究奠定基础。这个项目有三个组成部分。PI和他的团队将使用大型双筒望远镜（LBT）、麦哲伦、凯克和甚大望远镜（VLT）天文台的光谱仪，对2z4的大样本低质量恒星形成星系进行调查。他们还将(2)比较低质量星系的发射谱线特性与大网格光电离模型预测的发射谱线特性。最后，该团队将(3)进行一项革命性的研究，利用Keck、VLT和LBT天文台上的近红外光谱仪，在z6星系中寻找[CIII]和其他的紫外发射线。PI还将与莱蒙山天空中心合作，为新开发的亚利桑那大学天空大使计划建立一个为期五周的星系外天文学课程。该项目将把地区高中教师与亚利桑那大学的许多可用资源联系起来，并将教授学生恒星演化和宇宙学的基础知识，同时将物理和化学课堂上常见的概念带入生活。

Witnessing the formation of the first galaxies is one of the key goals of extragalactic astrophysics. Astronomers wish to understand when galaxies first emerge, what physical processes regulate their early evolution, and to what extent their star formation drives the subsequent evolution of the universe. The research enabled by this NSF award will fundamentally resolve long-standing questions about the makeup of the universe in its first billion years, and it will form the bedrock of future studies with ground- and space-based telescopes.This program has three components. The PI and his team will (1) perform a survey of large sample of low mass star-forming galaxies at 2 z 4 using optical spectrographs on the Large Binocular Telescope (LBT), Magellan, Keck, and Very Large Telescope (VLT) observatories. They will also (2) compare emission line properties of low mass galaxies to those predicted from large grid of photoionization models. Finally, the team will (3) perform a transformative study to search for [CIII] and other rest-UV emission lines in z 6 galaxies using near-infrared spectrographs on the Keck, VLT, and LBT observatories.The PI will also work with the Mount Lemmon Sky Center to build a 5-week curriculum on extragalactic astronomy for the newly-developed University of Arizona Sky Ambassador program. The program will link regional high school teachers to the many resources available at the University of Arizona, and will teach students the basics of stellar evolution and cosmology, while bringing to life commonly taught concepts in physics and chemistry classes.