Study of Galactic Structure and Evolution

银河系结构与演化研究

• 批准号: 9624924
• 负责人: Alexander Rudolph
• 金额: $ 35.91万
• 依托单位: Harvey Mudd College
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1996
• 资助国家: 美国
• 起止时间: 1996-08-01 至 2001-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9624924&HistoricalAwards=false
• 关键词: Study; Galactic; Structure; Evolution

9624924 Rudolph The study of galactic structure and evolution is one of the most fundamental in Astronomy. The research to be carried will focus on studying the structure and evolution of our own Milky Way by comparing observations of two distinct parts of our Galaxy, the local solar neighborhood, and the outer Galaxy. The solar neighborhood is the best studied region of the Galaxy. The outer Galaxy is less well understood, but its proximity and differences in physical conditions (e.g., low gas density, low metallicity) make it an ideal place to study contrasts with the local neighborhood. The areas of study be: 1) searches for and studies of atomic hydrogen (HII) regions in the outer Galaxy; 2) a study of Galactic abundances and how they vary in the Galaxy; 3) studies of molecular cloud structure; and 4) studies of the stellar content of regions of active star-formation. A Very Large Array (VLA) and Australia Telescope Compact Array (ATCA) radio continuum survey of HII regions in the outer Galaxy has begun, and this work will be continued by analyzing the data to determine HII region properties. These data can be compared with similar data taken in the inner Galaxy. The survey will be carried out to observe lower luminosity radio sources. A study of outer Galaxy abundances (N,O,S) in HII regions measured from the Kuiper Airborne Observatory. The Infrared Satellite Observatory (ISO) will be used to observe additional lines of Ar and Ne in some outer Galaxy HII regions, and to measure abundances in the furthest known HII region at a distance of 28 kpc from the center of the Galaxy. A third objective will involve new molecular-line observations of two star-forming regions in the outer Galaxy in order to determine the structure of the molecular clouds. In particular, it is planned to measure the spectrum of clump masses (initial clump function, or ICF) in t hese clouds in order to compare with the numerous measurements of the ICF parameter in local clouds. The final objective is to obtain JHK photometry of a number of nearby star-forming clouds using a near-IR camera mounted on the Claremont Colleges l-m telescope. With this telescope and camera, entire clouds could be mapped (such as rho-Oph), thereby obtaining a complete census of the embedded cluster. Models of the observed cluster luminosity function will allow us to determine the underlying IMF. Similar cluster membership data for the outer Galaxy will be obtained, allowing one to compare the IMF in two regions of very different metallicity. Also, comparison of the ICF and lMF in both the local neighborhood and in the outer Galaxy will help one understand how star-formation proceeds from molecular cloud clumps to stars of various masses. The educational component of this project will focus on course development and modernization. The Observational Astronomy course offered at Harvey Mudd College has, in the past, neglected including recent advances in non-optical astronomy. New lecture material and computer laboratories are being developed to introduce non-optical data into the course. The Advanced Astronomy course will be redesigned into a series of topical half-semester courses (e.g., Star-formation and the Interstellar Medium, Cosmology, Extragalactic Astronomy, Galactic Structure, etc.) to introduce modern astronomical topics into the curriculum and to increase student interest in advanced Astronomy. The educational component of this project will also continue K-12 outreach work begun in the last year, through a partnership with two local Claremont School District teachers.

9624924 鲁道夫 银河结构和演化的研究是天文学中最基本的研究之一。 即将进行的研究将侧重于通过比较对银河系两个不同部分（本地太阳邻域和外星系）的观测结果来研究我们银河系的结构和演化。 太阳系附近是银河系中研究最深入的区域。 外星系的了解还不太清楚，但它的邻近性和物理条件的差异（例如低气体密度、低金属丰度）使其成为研究与当地邻近区域对比的理想场所。 研究领域为：1）外星系原子氢（HII）区域的搜寻和研究； 2）研究银河系丰度及其在银河系中的变化； 3）分子云结构研究； 4）研究活跃恒星形成区域的恒星含量。 对外星系 HII 区域的甚大阵列 (VLA) 和澳大利亚望远镜紧凑阵列 (ATCA) 射电连续谱勘测已经开始，这项工作将通过分析数据来确定 HII 区域特性来继续进行。 这些数据可以与在银河系内部获取的类似数据进行比较。 该调查的目的是观察亮度较低的射电源。 对柯伊伯机载天文台测量的 HII 区域外星系丰度（N、O、S）的研究。 红外卫星天文台（ISO）将用于观测银河系 HII 外层区域的额外 Ar 和 Ne 线，并测量距离银河系中心 28 kpc 的最远已知 HII 区域的丰度。 第三个目标将涉及对外星系两个恒星形成区域进行新的分子线观测，以确定分子云的结构。 特别是，计划测量这些云中的团块质量谱（初始团块函数，或 ICF），以便与本地云中 ICF 参数的大量测量结果进行比较。 最终目标是使用安装在克莱蒙特学院 l-m 望远镜上的近红外相机获得 JHK 附近许多恒星形成云的光度测量。 使用这台望远镜和相机，可以绘制整个云层（例如 rho-Oph），从而获得嵌入式星团的完整普查。 观测到的星团光度函数模型将使我们能够确定潜在的 IMF。 我们将获得外星系类似的星团成员数据，从而可以比较金属丰度截然不同的两个区域的 IMF。 此外，比较本地邻域和外星系的 ICF 和 lMF 将有助于人们了解恒星形成过程如何从分子云团发展为不同质量的恒星。 该项目的教育部分将侧重于课程开发和现代化。 哈维穆德学院提供的观测天文学课程过去忽略了非光学天文学的最新进展。 新的讲座材料和计算机实验室正在开发中，以将非光学数据引入课程中。 高等天文学课程将重新设计为系列半学期专题课程（如恒星形成与星际介质、宇宙学、河外天文学、银河结构等），将现代天文学话题引入课程，提高学生对高等天文学的兴趣。 该项目的教育部分还将通过与两名当地克莱蒙特学区教师的合作，继续去年开始的 K-12 外展工作。