CAREER: Probing the High-Redshift Universe with Quasar Element Abundances

职业：利用类星体元素丰度探索高红移宇宙

• 批准号: 9984040
• 负责人: Frederick Hamann
• 金额: --
• 依托单位: University of Florida
• 依托单位国家: 美国
• 项目类别: Continuing grant
• 财政年份: 2000
• 资助国家: 美国
• 起止时间: 2000-05-01 至 2007-04-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9984040&HistoricalAwards=false
• 关键词: CAREER; Probing; Redshift; Universe; Quasar

AST-9984040HAMANNQuasars (or QSOs) are bright beacons at the fringes of the observable universe. The light we measure today from the most distant of these objects was emitted when the universe was about 17% of its present age - roughly 1-2 billion years old. Spectroscopic studies show that even at these early times quasars contain heavy elements (or "metals"'), presumably a synthesized by local stars. This project is a five-year program to use quasar elemental abundances as tracers of star formation and galaxy evolution at early cosmological epochs. The enrichment time scales and physical conditions inferred from the abundances (such as the ages, gravitational binding energies, and perhaps total masses of the star-forming environments) should also help constrain models of the cosmology itself. Early-epoch star formation and galaxy evolution are among the most active research topics in astronomy today. This program's emphasis on the abundances near QSOs will provide a vital complement to other studies that probe more extended structures or use very different data and analysis techniques. The results will be particularly valuable for their unique constraints on galactic nuclear evolution. It has been shown that reliable abundances and important star-formation properties can be derived from the intrinsic emission and absorption lines in quasar spectra. This program will test and expand upon those results by 1) including larger QSO data samples - with an emphasis on the earliest epochs, 2) developing and comparing more independent abundance diagnostics, 3) targeting specifically the relative iron abundances to constrain the enrichment time scales, and 4) comparing the QSO results directly to other studies of high-redshift star formation and galaxy evolution. The same data and analyses will also necessarily address a variety of problems concerning the QSOs themselves. The results of the investigations will allow one to address fundamental issues, such as the formation and evolution of QSOs, and the origin, location, dynamics and physical nature of their environments.An integral part of the program is a long-range plan for education and public outreach. This plan includes 1) strategies for bringing science to K-12 students and the general public, 2) new interactive and "hands-on"' programs for undergraduates, and 3) a mentoring plan for graduate students that will prepare them for a range of career options, including education, industry and academic research. The goal is to design projects for graduate student classes that will enhance their skills in "practical" applications, team management, communication and organization. Meetings with industry representatives will be arranged and the students will be sent out to local industry centers and industry representatives will be invited to visit the astronomy department. A weekly series of journal club talks (for students and faculty) will be organized and the graduate students will go out into local K--12 schools to participate in a program of public outreach. This outreach program will benefit the K-12 students by stirring their enthusiasm for science and by having the graduate students be examples of positive role models. The undergraduate education plan includes innovative classroom techniques such as "concept testing," exposure to current research as part of the normal curriculum, and summer research projects for motivated juniors and seniors.The Division of Astronomical Sciences provides support for this project.***

类星体（或qso）是可观测宇宙边缘的明亮灯塔。我们今天从这些物体中最遥远的地方测量到的光，是在宇宙年龄约为现在年龄的17%的时候发出的，大约有10 - 20亿年的历史。光谱研究表明，即使在这些早期，类星体也含有重元素（或“金属”），可能是由当地恒星合成的。这个项目是一个为期五年的计划，利用类星体元素丰度作为早期宇宙时期恒星形成和星系演化的示踪剂。从丰度推断出的富集时间尺度和物理条件（如年龄、引力结合能，也许还有恒星形成环境的总质量）也应该有助于约束宇宙学本身的模型。早期恒星形成和星系演化是当今天文学中最活跃的研究课题之一。这个项目的重点是在qso附近的丰度，这将为其他研究提供重要的补充，这些研究探测更多的扩展结构或使用非常不同的数据和分析技术。这些结果将特别有价值，因为它们对星系核演化的独特限制。已经证明，从类星体光谱的本征发射和吸收谱线可以推导出可靠的丰度和重要的恒星形成特性。该项目将测试和扩展这些结果，包括1)包括更大的QSO数据样本-重点是最早的时代，2)开发和比较更独立的丰度诊断，3)专门针对相对铁丰度来限制富集时间尺度，4)将QSO结果直接与其他高红移恒星形成和星系演化的研究进行比较。同样的数据和分析也必须解决与qso本身有关的各种问题。调查结果将有助研究基本问题，例如qso的形成和演化，以及它们所处环境的起源、位置、动态和物理性质。该方案的一个组成部分是教育和公众宣传的长期计划。该计划包括：1)将科学带给K-12学生和普通大众的策略；2)为本科生提供新的互动和“动手”项目；3)为研究生提供指导计划，为他们的一系列职业选择做好准备，包括教育、工业和学术研究。其目标是为研究生班级设计项目，以提高他们在“实际”应用、团队管理、沟通和组织方面的技能。将安排与业界代表会面，学生将被派往当地的工业中心，并邀请业界代表参观天文系。每周将组织一系列的期刊俱乐部讲座（针对学生和教师），研究生将到当地的K- 12学校参加一个公共宣传项目。这个拓展项目将通过激发K-12学生对科学的热情，并让研究生成为积极的榜样，从而使他们受益。本科教育计划包括创新的课堂技术，如“概念测试”，将当前研究作为正常课程的一部分，以及为有动力的大三和大四学生提供暑期研究项目。天文科学司为这个项目提供支持