Imaging the Universe in the Far-Infrared

我最近回到加拿大，担任加拿大实验天体物理学研究主席（CRC），建立一个试验平台，探索与远红外（FIR）波长的空间/光谱干涉测量相关的挑战。这被广泛认为是导致FIR成像光谱学下一个重大进步的技术。宇宙发射的能量有一半以上出现在相对未被探索的FIR光谱区域，其中大部分是不透明的地面站点需要星载仪器。欧洲航天局的普朗克和赫歇尔望远镜最近提供了FIR中第一个不受约束的宇宙视图。他们重新定义了当前的天体物理学，包括银河系和河外源，以尽可能远的光子。赫歇尔，其3.5米直径的主镜，也强调了“FIR差距”，即显着较差的角分辨率和灵敏度在FIR相比，任何一侧的这个频谱。许多赫歇尔发现正在等待增强的空间分辨率后续观测，以解决这个新的宇宙窗口中提出的问题。天文学长期计划已确定冷却孔径和干涉测量作为两个FIR路线图的优先事项。日本领导的宇宙学和天体物理学空间红外望远镜（SPICA）是下一代赫歇尔望远镜。由于主动冷却的主镜尺寸与赫歇尔相似，而且探测器更灵敏，SPICA的灵敏度有望超过赫歇尔100倍。因此，SPICA将具有更快的映射速度和天空覆盖范围，但空间分辨率与Herschel相似。Herschel在积分时间秒内获得了混淆限制的光度观测。即使SPICA的灵敏度将允许光谱歧视，以部分规避空间源混淆，我们正在接近一个基本的限制，在单碟FIR的能力。FIR需要改进到更好的空间分辨率，以降低混淆限制，并允许实现其他进步的全部潜力。传统的成像必须由干涉技术取代，以克服这一基本的远红外线障碍，就像阿塔卡马大型毫米阵列和平方公里阵列等干涉仪正在取代其他频率的单碟观测台一样。虽然我的研究重点是基于实验室的FIR干涉测量测试平台的开发，但它有助于FIR路线图的许多方面，包括利用当前的结果和设施，以及与未来实验，设施和观测站的合作。我的研究项目是与莱斯布里奇大学（UL）天文仪器集团（AIG）合作。在大卫内勒的领导下，AIG提供了一个世界级的环境，拥有超过500万美元的设备，并在过去30年中建立了国际声誉。FIR干涉测量的重点为AIG开辟了一条新的研究途径，并代表了UL在其战略计划的关键支柱之一的国际认可基础上的重大投资。我的研究提供了一个底层的机会，成为未来一代地面和天基FIR天文学的关键合作伙伴，以及优秀的高素质人才（HQP）培训机会。这项工作在加拿大和世界上都是独一无二的，补充了当地和国际上现有的研究网络，并将加强现有和预期的国际合作。我的研究将通过动手仪器，技术，技巧和数据处理的发展与参与国际合作的广阔前景相结合，为许多学生提供HQP培训。

I have recently returned to Canada as a Canada Research Chair (CRC) in experimental astrophysics to establish a testbed for exploring the challenges associated with spatial/spectral interferometry at Far-Infrared (FIR) wavelengths. This is widely regarded as the technology that will lead to the next major advance in FIR imaging spectroscopy. Over half of the energy emitted by the Universe appears in the relatively unexplored FIR spectral region, most of which is opaque from ground-based sites necessitating space-borne instrumentation. The European Space Agency Planck and Herschel telescopes have recently provided the first unfettered views of the universe in the FIR. They have redefined current astrophysics including galactic and extragalactic sources, to the most distant photons possible. Herschel, with its 3.5m diameter primary mirror, has also highlighted the "FIR gap", i.e. the dramatically poorer angular resolution and sensitivity in the FIR compared with either side of this spectrum. Many Herschel discoveries are waiting on enhanced spatial resolution follow-up observations to address the questions raised in this new window on the Universe. The astronomy long range plan has identified cooled apertures and interferometry as two FIR roadmap priorities. The Japanese-led Space Infrared Telescope for Cosmology and Astrophysics (SPICA) is the next-generation Herschel. With an actively cooled primary mirror similar in size to Herschel and more sensitive detectors, SPICA is expected to outperform Herschel in sensitivity by a factor of 100. Thus, SPICA will have greater mapping speed and sky coverage, but at similar spatial resolution to Herschel. Confusion limited photometric observations are obtained by Herschel in seconds of integration time. Even though SPICA's sensitivity will allow spectroscopic discrimination to partially circumvent spatial source confusion, we are approaching a fundamental limit in single-dish FIR capabilities. FIR improvements to much better spatial resolution are needed to lower the confusion limit and allow the full potential of other advances to be realized. Traditional imaging must be replaced by interferometric techniques to overcome this fundamental FIR barrier, much like interferometers such as the Atacama large millimetre array and square kilometre array are replacing single-dish observatories at other frequencies. While my research is focused on the development of a lab-based FIR interferometry testbed, it contributes to many aspects of the FIR roadmap including the exploitation of current results and facilities, and collaboration with future experiments, facilities, and observatories. My research program is in partnership with the University of Lethbridge (UL) Astronomical Instrumentation Group (AIG). Led by David Naylor, the AIG provides a world-class environment with equipment in excess of $5M and an international reputation built over the last 30 years. The FIR interferometry focus opens a new research avenue for the AIG, and represents significant UL investment to build on international recognition within one of the key pillars in its strategic plan. My research provides a ground floor opportunity to become a key partner in future-generation ground and space-based FIR astronomy, and excellent highly qualified personnel (HQP) training opportunities. This work is unique within Canada, and the world, complements the existing research network both locally and internationally, and will fortify existing and anticipated international collaborations into the future. My research will provide HQP training to many students through a combination of hands-on instrumentation, technology, technique, and data processing developments with the broad perspective of participation in international collaborations.