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.

宇宙是如何开始的以及我们的银河系从何而来？解决这些问题涉及研究大爆炸（宇宙微波背景 - CMB）后立即发出的毫米波光和受其影响的毫米波光，以及来自早期宇宙中首次形成恒星的遥远星系的近红外毫米波光。大部分恒星形成过程都被尘埃深深遮盖，来自年轻热恒星的紫外线辐射被加热到约 30K 的尘埃以长波长吸收和再辐射。在早期宇宙的星系形成时期，当恒星形成率（SFR）足够高，可以在几兆年的时间内形成典型星系中的大部分恒星时，“原星系”在光波长下几乎完全不可见。宇宙的最初约 70 亿年是一个特别值得探索的关键时间框架——它标志着气体质量分数、气体吸积率和恒星形成率大幅提高的时期，导致早期星系的生长发生了根本性的差异。 ***我的提案有两个相关的组成部分； ***(i) 通过毫米波望远镜了解早期宇宙和约束结构的形成； ***(ii) 使用自适应光学改进的光谱映射来探测星系的运动演化。***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遥远宇宙中原始星系和原始星系团中模糊的恒星形成。这些目标还涉及大型毫米波望远镜/实验（Polarbear、SPT、CCAT 和大型毫米波望远镜）和大型光学望远镜（双子座）仪器的开发，最终形成了三十米望远镜 - TMT（最近加拿大合作投资 2.5 亿美元！）。最近投入使用的低背景测试低温恒温器将用于研究毫米波探测器关键组件的光学和热特性，这些探测器将部署在当前正在实施和即将进行的 CMB 偏振实验中。评估低温探测器性能的能力将使加拿大成为未来（亚）毫米波天文学实验的首选合作伙伴。***最近发布的加拿大天文学十年计划中期审查呼吁通过支持TMT“第二代仪器概念的持续开发”来保持“首屈一指”的地位。***我们正在建造一台仪器 Gemini-IRMOS，它将作为最重要的天文学的探路者。 TMT 上备受科学追捧的仪器功能是近红外多目标积分场光谱仪 (IRMOS)。由于自适应光学技术的快速发展、复杂性以及降低风险需要在当前望远镜上成功实施的认识，IRMOS 被留给了第二代。