The Dusty Universe

尘封的宇宙

• 批准号: RGPIN-2018-06740
• 负责人: Chapman, Scott
• 金额: $ 2.48万
• 依托单位: Dalhousie University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2019
• 资助国家: 加拿大
• 起止时间: 2019-01-01 至 2020-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=685390
• 关键词: Dusty; Universe

How did the Universe begin and where did our Galaxy come from? Addressing these questions involves studying millimeter-wave light emitted and affected by processes immediately after the Big Bang (the Cosmic Microwave Background - CMB), as well near-infrared through millimetre light from distant galaxies in the early Universe first forming their stars. The bulk of star formation is deeply obscured by dust, with ultra-violet radiation from young, hot stars being absorbed and reradiated at long wavelengths from dust heated to ~30K. In the formative periods of galaxies in the early Universe, when star formation rates (SFRs) were high enough to form the bulk of the stars in a typical galaxy in a few mega-years, the `proto-galaxies' were almost completely invisible at optical wavelengths. The first ~7billion years of the universe is an especially crucial time frame to explore -- it marks a time when gas mass fractions, gas accretion rates, and star formation rates were substantially higher, resulting in a fundamental difference in the growth of galaxies at early times. ***My proposal has two related components; ***(i) Understanding the Early Universe and Constraining Structure Formation through Millimeter-Wave Telescopes; ***(ii) Probing the Kinematic Evolution of Galaxies using Spectral Mapping improved by Adaptive Optics.***Both goals involve the use telescope data from various facilities to probe obscured star formation in primeval galaxies and proto-clusters of galaxies in the distant universe. These goals also involve development of instrumentation for large millimetre-wave telescopes/experiments (Polarbear, SPT, CCAT, and the Large Millimetre Telescope), and large optical telescopes (Gemini), culminating in the Thirty Meter Telescope - TMT (a recent Canadian partnership investment of $250Mil!). A recently commissioned, low background, test cryostat will be used to study optical and thermal properties of key components in millimetre-wave detectors to be deployed on currently implementing and upcoming CMB-polarization experiments. The ability to evaluate the performance of detectors at cryogenic temperatures will position Canada to be a partner of choice in future (sub)millimetre wave astronomy experiments.***The recently released midterm review of Canadian astronomy's decadal plan has called for maintaining the “second to none” status by endorsing “ongoing development of second generation instrument concepts” for TMT.***We are building an instrument Gemini-IRMOS that will serve as a pathfinder for the most scientifically sought after instrument capability on the TMT, the nearIR multi-object integral-field spectrograph (IRMOS). IRMOS was left for the second generation due to rapidly advancing adaptive optics technology, complexity, and the recognition that risk reduction requires successful implementation on a current telescope.

宇宙是如何开始的？我们的银河系从哪里来？解决这些问题需要研究大爆炸后立即发射和受过程影响的毫米波光(宇宙微波背景-CMB)，以及来自早期宇宙中最早形成恒星的遥远星系的近红外至毫米光。恒星形成的大部分都被尘埃深深地遮盖住了，年轻、炽热的恒星发出的紫外线被吸收，并从加热到约30K的尘埃中以长波长重新辐射。在早期宇宙中星系的形成时期，当恒星形成率(SFR)高到足以在几个百万年内形成一个典型星系中的大部分恒星时，在光学波长上几乎完全看不到“原星系”。宇宙的头70亿年是一个特别关键的时间框架，值得探索--它标志着气体质量分数、气体吸积率和恒星形成率显著较高的时期，导致早期星系增长的根本不同。*我的建议有两个相关的部分；*(I)了解早期宇宙并通过毫米波望远镜限制结构的形成；*(Ii)使用自适应光学改进的光谱映射来探索星系的运动学演化。*这两个目标都涉及使用来自各种设施的望远镜数据来探测原始星系和遥远宇宙中的原始星系团中模糊的恒星形成。这些目标还包括为大型毫米波望远镜/实验(Polarear、SPT、CCAT和大毫米望远镜)和大型光学望远镜(Gemini)开发仪器，最终形成30米望远镜-TMT(最近加拿大伙伴关系投资2.5亿美元！)。最近投入使用的低本底低温恒温器将用于研究毫米波探测器中关键部件的光学和热性质，该探测器将部署在目前正在实施和即将进行的CMB偏振实验中。在低温下评估探测器性能的能力将使加拿大成为未来(亚)毫米波天文实验的首选合作伙伴。*最近发布的加拿大天文学十年计划的中期审查呼吁通过支持TMT的“正在进行的第二代仪器概念的发展”来保持“首屈一指”的地位。*我们正在建造一台仪器Gemini-IRMOS，它将成为TMT上最受科学追求的仪器能力的探路者，近红外多目标积分场光谱仪(IRMOS)。由于快速发展的自适应光学技术和复杂性，以及人们认识到降低风险需要在现有望远镜上成功实施，IRMOS被留给了第二代。