CAREER: The Interstellar Disk-Halo Connection in Edge-on Galaxies - Bringing Research to a Large Audience

职业：边缘星系中的星际盘-光环连接 - 将研究成果带给广大受众

• 批准号: 9986113
• 负责人: Richard Rand
• 金额: $ 28.7万
• 依托单位: University of New Mexico
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2000
• 资助国家: 美国
• 起止时间: 2000-05-01 至 2006-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9986113&HistoricalAwards=false
• 关键词: CAREER; Interstellar; Disk; Halo; Connection

AST-9986113RandIn recent years it has been realized that the Interstellar Medium (ISM) and galaxy evolution depend pivotally on the cycling of gas between a galaxy's disk and halo. Recent discoveries of huge, vertically extended coherent structures in the ISM are called superbubbles and chimneys. The results from observations of thick layers of diffuse gas have enabled scientists to begin to form a picture of how stars energize and shape the ISM, and how, through these processes, the diffuse gas affects the future evolution of a galaxy. This "disk-halo connection" is therefore critical for star formation feedback on the ISM, chemical evolution, and possibly the escape of gas from galaxies and the production of large gaseous halos responsible for QSO metal absorption line systems.A feature of the ISM, which is now giving us a strong handle on the disk-halo connection, is the Diffuse Ionized Gas (DIG). In the Milky Way Galaxy, this vertically extended medium is known as the Reynolds layer. While it is generally accepted that the great thickness of the Reynolds layer is probably due to processes such as chimneys, we still have only a rudimentary understanding of (a) the extent of the layer and variations thereof, (b) sources of ionization and heating, (c) the kinematics of the gas far from the plane, and (d) the relation of other thick gaseous layers to the Reynolds layer and the disk-halo connection. For several reasons, many ISM issues are better addressed through studies of external galaxies, which provide a synoptic view of the emission. The relatively new area of DIG in edge-on spirals, where recent efforts have been focused, has given us a powerful tool for understanding the disk-halo connection and the ISM in general. Through imaging of edge on galaxies we are now beginning to obtain information on the structure of DIG layers and their relation to other thick gaseous layers and star formation activity. The DIG is found to be an excellent tracer of candidate chimneys. Spectroscopy of DIG layers is now being used to study the ionization, heating, kinematics and vertical extent at faint levels of this phase. Hence, such observations have great potential to address the four issues listed above. The goal of this research effort is to expand greatly these DIG observations using sensitive spectroscopy and new imaging possibilities, and to carry out searches for neutral hydrogen (HI) and cosmic ray halos. In this way it is hoped to learn about how the disk-halo connection operates in detail, as input into our larger understanding of galaxy evolution.Information on the research that is being carried out will be brought to a large audience as part of an effort to improve scientific awareness and literacy. An innovative project at the University of New Mexico (UNM), called LodeStar, combines education and outreach with information on current forefront research. LodeStar will soon open an Astronomy Science Center in Albuquerque, thus providing the infrastructure for bringing research results to the public. Through a theme called "Galaxies Across the Electromagnetic Spectrum", the interpretations and explanations of the results of this research, and results from the UNM astronomy group in general, will be used to develop programs to educate the general public and K-12 school classes about the physics of galaxies, the methods of astronomy, and the importance of astronomical research in their own State. Crucially, ethnic groups underrepresented in science, but with a strong presence in New Mexico, will be reached through these efforts. Thus the awareness of opportunities to study science at all levels will be increased. Other roles for LodeStar will be developed which will lead to effective public outreach projects. ***

AST-9986113 Rand近年来，人们认识到星际介质（ISM）和星系演化取决于星系盘和晕之间的气体循环。最近在ISM中发现的巨大的、垂直延伸的相干结构被称为超级气泡和烟囱。 对厚层扩散气体的观测结果使科学家们开始形成一幅恒星如何激发和塑造ISM的图像，以及扩散气体如何通过这些过程影响星系的未来演化。因此，这种“盘晕连接”对于星星的形成反馈、化学演化、气体从星系中逃逸以及类星体金属吸收线系统的大的气体晕的产生都是至关重要的。在银河系中，这种垂直延伸的介质被称为雷诺层。虽然人们普遍认为，雷诺层的厚度很大可能是由于诸如烟囱之类的过程造成的，但我们对下列问题仍然只有初步的了解：（a）雷诺层的范围及其变化;（B）电离和加热的来源;（c）远离平面的气体的运动学;（d）其他厚气体层与雷诺层的关系以及盘-晕的联系。 出于几个原因，许多ISM问题更好地解决通过研究外部星系，它提供了一个发射的天气视图。在边缘螺旋中的相对较新的DIG领域，最近的努力已经集中，给了我们一个强大的工具来理解盘-晕连接和ISM。通过对星系边缘的成像，我们现在开始获得有关DIG层结构及其与其他厚气体层和星星形成活动的关系的信息。DIG被认为是候选烟囱的一个很好的示踪剂。光谱的DIG层现在被用来研究电离，加热，运动学和垂直范围在这个阶段的微弱水平。因此，这种观察具有解决上述四个问题的巨大潜力。这项研究工作的目标是利用灵敏的光谱学和新的成像可能性大大扩展这些DIG观测，并进行中性氢（HI）和宇宙射线晕的搜索。通过这种方式，我们希望能够详细了解盘-晕连接是如何运作的，作为我们对星系演化的更广泛理解的投入。正在进行的研究的信息将作为提高科学意识和素养的努力的一部分被带给广大观众。 新墨西哥州大学（UNM）的一个创新项目，称为LodeStar，将教育和推广与当前前沿研究的信息相结合。LodeStar将很快在阿尔伯克基开设一个天文科学中心，从而为向公众提供研究成果提供基础设施。通过一个名为“跨越电磁频谱的星系”的主题，对这项研究结果的解释和解释，以及UNM天文学小组的一般结果，将用于制定方案，教育公众和K-12学校班级关于星系物理学，天文学方法以及天文学研究在自己国家的重要性。 至关重要的是，通过这些努力，将接触到在科学领域代表性不足，但在新墨西哥州有很强影响力的族裔群体。 因此，将提高对各级学习科学机会的认识。 LodeStar的其他作用将得到发展，这将导致有效的公共宣传项目。***