NSF Young Investigator: The Evolution of Normal Galaxies

NSF 青年研究员：正常星系的演化

• 批准号: 9457446
• 负责人: Charles Steidel
• 金额: --
• 依托单位: Massachusetts Institute of Technology
• 依托单位国家: 美国
• 项目类别: Continuing grant
• 财政年份: 1994
• 资助国家: 美国
• 起止时间: 1994-07-15 至 1996-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9457446&HistoricalAwards=false
• 关键词: NSF; Young; Investigator; Evolution; Normal

9457446 Steidel Over the course of the next several years, a number of inter-related projects will be pursued which address the broad question of the history of "normal", Milky-Way-like galaxies from the epoch of their formation to the present time. The studies are based on a combination of the technique of quasar absorption line spectroscopy and more conventional optical and near-infrared imaging and spectroscopy of very faint, distant galaxies. The objects for study are selected on the basis of their having produced hydrogen and metallic absorption lines in the spectra of even more distant, background quasars. High resolution spectroscopy of the quasars yields extremely detailed physical information on the galaxies producing the absorption, even for galaxies whose mere detection (using conventional methods) strains our technological capabilities at the present time. Samples of galaxies, selected in essence by their gas cross-section, are constructed without any biases related to the nature of stellar radiation being emitted by the galaxies as a function of time. The samples represent a very large range of cosmic epochs, from times when the Universe was only 10% of its current age, to the present. One then combines this information with data that is obtained from direct identification of the galaxies producing the absorption line systems using imaging and low-dispersion galaxy spectroscopy in the optical and the near-infrared. These latter data provide information on the stellar populations, luminosities, and geometrical orientations with respect to the line of sight to the quasars. In total, then, one obtains information on the chemical composition, gas-phase structure, kinematics, luminosity distribution, ionization state, space density, and clustering properties of galaxies as a function of time. The marriage of these methods, all of which can be pursued using currently existing instrumentation on large ground-based telescopes, allows the construct ion of a detailed history of normal galaxies since the time of their formation. Galaxy formation and evolution theories are at present largely unconstrained by observations, and it is the intent of this research effort to place the subject on a firm empirical footing. This award is to recognize an outstanding young faculty member in science and engineering. The award will enhance the career of the faculty member by providing flexible support for research and educational activities. Cooperation with industry and institutions that support research and education is encouraged.

小行星9457446 在今后几年中，将开展一些相互关联的项目，解决“正常”银河系从形成到现在的历史这一广泛问题。这些研究是基于类星体吸收线光谱技术和更传统的光学和近红外成像技术以及非常微弱的遥远星系光谱技术的结合。 研究对象的选择是基于它们在更遥远的背景类星体的光谱中产生了氢和金属吸收线。 类星体的高分辨率光谱学产生了关于产生吸收的星系的极其详细的物理信息，即使是对于那些仅仅检测（使用传统方法）使我们目前的技术能力紧张的星系。 星系的样本，选择在本质上是由他们的气体横截面，没有任何偏见的星系发射的恒星辐射的性质作为时间的函数。 这些样本代表了非常大范围的宇宙时代，从宇宙只有当前年龄的10%的时候到现在。 然后将这些信息与使用光学和近红外成像和低色散星系光谱直接识别产生吸收线系统的星系所获得的数据相结合。 后者的数据提供了恒星的人口，光度和几何方向相对于视线的类星体的信息。 总的来说，我们可以获得关于化学成分、气相结构、运动学、光度分布、电离状态、空间密度和星系团性质随时间变化的信息。 这些方法的结合，所有这些都可以使用现有的大型地面望远镜上的仪器进行，允许构建正常星系自形成以来的详细历史。 星系形成和演化理论目前在很大程度上不受观测的约束，本研究的目的是将这一主题置于坚实的经验基础上。 这个奖项是为了表彰一位杰出的年轻教师在科学和工程。 该奖项将通过为研究和教育活动提供灵活的支持来提高教师的职业生涯。 鼓励与支持研究和教育的行业和机构合作。