Collaborative Research: Addressing the Burning Questions in the Baryon Cycle at z~2

天文学家想要了解星系是如何成长的。他们特别想知道为什么在宇宙年轻的时候恒星形成的速度是最高的。Shapley， Reddy和Steidel将分析凯克望远镜对数千个遥远星系的观测结果。他们将研究流入和流出星系的物质如何影响恒星形成的速度和其他关键的星系特性。在与世界望远镜大使计划的合作下，pi将开发横跨夜空的互动之旅。其中一个行程将展示望远镜是如何充当时光机器的。当地的高中学生和他们的老师将被邀请参加加州理工学院的暑期研究联系项目。PI和她的团队将把这些学生培养成未来的科学家。Shapley， Reddy和Steidel在Keck重子结构调查（KBSS）和MOSFIRE深度演化场调查（MOSDEF）中发现了宇宙中恒星形成高峰期（z~1.5-3.5）的代表性星系样本。约20%的星系也有深凯克/LRIS静紫外光谱，约100个星系有凯克KCWI仪器的积分场单元图。co- pi将在这一时期对星系内的气体和恒星建立可靠的金属丰度测量；他们将根据“桶下”星系光谱学确定气体流出和流入的运动学和几何形状；他们将绘制更广泛的环星系介质（CGM）中的气体分布和运动学图，将CGM尺度的性质与星系尺度的性质联系起来。总的来说，这些结果将测试和告知星系演化中重子循环的前沿模型。由缩减后的Keck MOSFIRE、LRIS和KCWI光谱数据组成的遗留数据集将在公共档案中提供。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Astronomers want to understand how galaxies grow. In particular they want to know why the rate of star formation was highest when the Universe was young. Shapley, Reddy, and Steidel will analyze observations of thousands of distant galaxies obtained with the Keck Telescopes. They will investigate how material flowing into and out of a galaxy can affect the rate of star formation and other key galaxy properties. In partnership with the WorldWide Telescope Ambassadors Program the PIs will develop interactive tours across the night sky. One tour will demonstrate how telescopes act as time machines. Local high school students and their teachers will be invited to participate in a Summer Research Connection program at Caltech. The PI and her team will train the students to be future scientists.Shapley, Reddy, and Steidel have identified a representative sample of galaxies at the epoch of peak star formation in the universe (z~1.5-3.5) in the Keck Baryonic Structure Survey (KBSS) and the MOSFIRE Deep Evolution Field (MOSDEF) Survey. A subset of ~20% also have deep Keck/LRIS rest-UV spectra, and ~100 galaxies have integral- field unit maps from the Keck KCWI instrument. The co-PIs will establish robust metallicity measurements of gas and stars within galaxies at this epoch; they will determine the kinematics and geometry of gas outflow and inflow based on "down the barrel" galaxy spectroscopy; they will map the gas distribution and kinematics in the more extended circumgalactic medium (CGM), connecting the CGM-scale properties with those on the galaxy scale. Collectively, these results will test and inform forefront models of baryonic cycling in galaxy evolution. A legacy dataset consisting of the reduced Keck MOSFIRE, LRIS, and KCWI spectroscopic data will be available in a public archive.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.