The Dynamic Interstellar Medium

动态星际介质

• 批准号: RGPIN-2020-05035
• 负责人: Hill, Alexander
• 金额: $ 1.75万
• 依托单位: University of British Columbia
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2021
• 资助国家: 加拿大
• 起止时间: 2021-01-01 至 2022-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=740366
• 关键词: Dynamic; Interstellar; Medium

The interstellar medium (ISM) mediates the evolution of galaxies as the reservoir of material for future star formation and the repository for energy and matter fed back by star formation processes. I use both observations and computer simulations to build a picture of the physical processes in the diffuse ISM which connect star formation at small scales to galaxies at large scales. My work is closely tied to the Dominion Radio Astrophysical Observatory (DRAO). I am an active member of the Canadian Hydrogen Intensity Mapping Experiment (CHIME) cosmology team. CHIME aims to detect hydrogen from when the Universe was about half its present age but must look through the Milky Way, the galaxy we live in. In order to remove this foreground, we must understand it, so I contribute to the cosmology mission through my work on Milky Way science with CHIME. Over the next five years, CHIME will provide a data set which enables unprecedented studies of the Milky Way, producing three-dimensional images of the Galactic magnetic field. I will also be a leader in the scientific use of a major upgrade to the DRAO Synthesis Telescope, enabling a wideband system to produce science that is a successor to the wildly successful Canadian Galactic Plane Survey. I will use this new system to produce an arcminute-resolution counterpart to the CHIME magnetic field survey, probing the star forming regions in the Galactic plane. The upgrade will also enable us to use dozens of radio recombination lines to map diffuse ionized gas throughout the Galactic plane, tracing the energy flow from massive stars through the Galaxy. In my simulations, I incorporate the physics that are relevant to the diffuse ISM, namely heating from stars, thermal and kinetic energy injection from supernovae, radiative cooling, and vertical gravity. This establishes a multi-phase ISM. With this grant, I will incorporate physical processes needed to investigate the vertical support of the different phases of the ISM, with particular focus on the poorly-understood warm ionized phase. All of this work will provide a training ground for highly qualified personnel including undergraduate and graduate students and postdocs. At UBC's Okanagan campus, we are working to build a graduate astrophysics program taking advantage of our geographical proximity and my close scientific ties to DRAO. My students and postdocs will work with the unique expertise of DRAO's scientific and engineering staff. As Canada's national radio astronomy observatory, DRAO has a unique combination of an outstanding radio quiet site and a mission to serve as a training ground for Canada's future radio astronomers and a testbed for new technologies and techniques. My research program uses the unique opportunities afforded by my skill set and my group's ready access to DRAO. We will use these resources to link together the multi-phase interstellar environment to understand how energy and matter are transported within galaxies.

星际介质（ISM）作为未来恒星形成的物质储存库和恒星形成过程反馈的能量和物质储存库，介导了星系的演化。我使用观察和计算机模拟来构建漫射ISM中物理过程的图像，它将小尺度的恒星形成与大尺度的星系联系起来。我的工作与多明尼安射电天体物理天文台（DRAO）密切相关。我是加拿大氢强度测绘实验（CHIME）宇宙学团队的活跃成员。CHIME的目标是探测宇宙年龄约为现在年龄一半时的氢，但必须穿越银河系，也就是我们生活的星系。为了消除这种前景，我们必须了解它，所以我通过与CHIME一起研究银河系科学，为宇宙学任务做出贡献。在接下来的五年里，CHIME将提供一个数据集，使前所未有的银河系研究成为可能，产生银河系磁场的三维图像。我还将领导对DRAO综合望远镜进行重大升级的科学应用，使宽带系统能够产生科学成果，这是成功的加拿大银河面测量的继承者。我将使用这个新系统产生一个弧形分辨率对应于CHIME磁场调查，探测银河系平面上的恒星形成区域。这次升级还将使我们能够使用数十条无线电重组线来绘制整个银河平面的漫射电离气体，追踪大质量恒星在银河系中的能量流。在我的模拟中，我结合了与漫射ISM相关的物理，即来自恒星的加热，超新星的热能和动能注入，辐射冷却和垂直重力。这样就建立了一个多相的ISM。有了这笔资金，我将纳入研究ISM不同阶段的垂直支撑所需的物理过程，特别关注人们知之甚少的热电离阶段。所有这些工作都将为培养包括本科生、研究生和博士后在内的高素质人才提供培训场所。在UBC的奥肯那根校区，我们正在努力建立一个研究生天体物理学项目，利用我们的地理位置和我与DRAO的密切科学联系。我的学生和博士后将在DRAO的科学和工程人员的独特专业知识下工作。作为加拿大的国家射电天文台，DRAO有一个独特的组合，它是一个杰出的射电安静地点，同时也是加拿大未来射电天文学家的训练场和新技术和技术的试验台。我的研究项目利用了我的技能所提供的独特机会，以及我的团队随时可以访问DRAO。我们将利用这些资源将多相星际环境联系在一起，以了解能量和物质如何在星系内运输。