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: 2022
• 资助国家: 加拿大
• 起止时间: 2022-01-01 至 2023-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=761810
• 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，调节着星系的演化。我使用观测和计算机模拟来构建漫射ISM中的物理过程的图像，该ISM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Dominion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(CHME)宇宙学团队的活跃成员。CHAME的目标是探测宇宙大约是现在年龄的一半时的氢，但必须透过我们生活的银河系进行观测。为了消除这一前景，我们必须理解它，所以我通过我与CHINE在银河系科学方面的工作为宇宙学任务做出了贡献。在接下来的五年里，CHINE将提供一个数据集，使人们能够对银河系进行史无前例的研究，产生银河系磁场的三维图像。我还将是DRAO合成望远镜重大升级的科学使用方面的领导者，使宽带系统能够产生科学成果，这是极其成功的加拿大银河系平面调查的后续成果。我将使用这个新系统来产生一个弧分分辨率的磁场测量对应的CHINE磁场，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复合线来绘制整个银河系平面上弥散的电离气体地图，追踪大质量恒星通过银河系的能量流动。在我的模拟中，我纳入了与漫射ISM相关的物理，即来自恒星的加热、来自超新星的热能和动能注入、辐射冷却和垂直重力。这建立了一个多阶段的ISM。有了这笔赠款，我将纳入调查ISM不同阶段垂直支持所需的物理过程，特别是对鲜为人知的热电离阶段的关注。所有这些工作将为包括本科生、研究生和博士后在内的高素质人才提供培训基础。在UBC的Okanagan校区，我们正在努力建立一个天体物理学研究生项目，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与DRAO的科学和工程人员的独特专业知识合作。作为加拿大的国家射电天文台，DRAO拥有出色的射电安静场地和作为加拿大未来射电天文学家训练场和新技术和新技术试验台的使命的独特组合。我的研究计划利用了我的技能提供的独特机会，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，以了解能量和物质在星系内是如何运输的。