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

AST-9986113近年来人们认识到星际介质(ISM)和星系演化主要依赖于星系盘和晕之间气体的循环。最近在ISM中发现的巨大的、垂直延伸的相干结构被称为超泡和烟囱。对厚层扩散气体的观察结果使科学家能够开始形成一幅图景，说明恒星是如何为ISM提供能量和塑造ISM的，以及通过这些过程，扩散气体如何影响星系的未来演化。因此，这种“盘-晕连接”对于恒星的形成、对ISM的反馈、化学演化、可能的气体从星系中逸出以及对类星体金属吸收线系统负责的大气态晕的产生都是至关重要的。ISM的一个特征是扩散电离气体(Dig)，它现在给了我们对盘-晕连接的强大控制。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巨大厚度可能是由于烟囱等过程造成的，但我们对(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，以及(D)其他厚气体层与雷诺层的关系和盘-晕连接仍然只有初步的了解。出于几个原因，通过研究外部星系可以更好地解决ISM的许多问题，因为外部星系提供了发射的概括性视图。在边缘螺旋中挖掘相对较新的领域，最近的努力是集中的，这给了我们一个强大的工具来理解盘-晕联系和ISM总体。通过对星系边缘的成像，我们现在开始获得关于挖掘层的结构以及它们与其他厚气体层的关系和恒星形成活动的信息。挖掘被发现是一个很好的候选烟囱的追踪器。DIG层的光谱现在被用来研究这一相在微弱水平上的电离、加热、运动学和垂直程度。因此，这些意见对解决上述四个问题具有很大潜力。这项研究的目标是利用灵敏的光谱学和新的成像可能性来极大地扩展这些DIG观测，并进行中性氢(HI)和宇宙线晕的搜索。通过这种方式，希望能详细了解盘-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输入。正在进行的研究的信息将被带给广大观众，作为提高科学意识和素养的努力的一部分。新墨西哥大学(UNM)的一个名为LODESTAR的创新项目将教育和外联与当前前沿研究的信息结合在一起。LODESTAR将很快在阿尔伯克基开设一个天文科学中心，从而为将研究成果带给公众提供基础设施。通过题为“电磁光谱上的星系”的专题，将利用对这项研究结果的解释和解释以及来自UNM天文学小组的一般结果，制定方案，教育普通公众和K-12学校班级关于星系物理、天文学方法以及天文研究在各自国家的重要性。至关重要的是，在科学界代表性不足但在新墨西哥州有强大存在的种族群体将通过这些努力得到触及。因此，将提高对各级学习科学机会的认识。还将发挥LODESTAR的其他作用，这将导致有效的公共外联项目。***

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. ***