Development of Sub-Millimetre Heterodyne Array & Probing the Interstellar Medium of Nearby Galaxies with JWST and ALMA

亚毫米外差阵列的研制

• 批准号: 2888233
• 金额: --
• 依托单位: University of Oxford
• 依托单位国家: 英国
• 项目类别: Studentship
• 财政年份: 2023
• 资助国家: 英国
• 起止时间: 2023 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=studentship-2888233
• 关键词: Development; Sub; Millimetre; Heterodyne; Array

This D.Phil. programme is comprising two complementary science topics: A focus on the development of the sub-millimetre quantum detector, and an observation project utilising mid-infrared (MIR) data from JWST and ALMA.The physical and chemical conditions in star-forming regions can be determined by observing at millimetre and sub-millimetre wavelengths, where a host of atomic, ionic and molecular lines can be found. In recent years, spectroscopic and interferometric observations of these lines have refined our knowledge of the gas dynamics and kinematics of nearby and distant galaxies, as well as enabling the first direct detection of black hole images. These observations have only been possible because of the extraordinary characteristics of near quantum-noise-limited Superconductor-Insulator-Superconductor (SIS) heterodyne receivers. SIS mixers are used routinely on observatories such as the Northern Extended Millimetre Array (NOEMA), the Atacama Large Millimetre/sub-millimetre Array (ALMA), and the Herschel space observatory, to name a few, enabling numerous observations of faint objects with high spectral and spatial resolution. However, there is a major limitation in utilising SIS receivers for near future astronomical observation, either ground-based or space-borne.Traditional high spectral resolution observations demand excessive telescope time. This hampers important scientific programs, especially when complementing large-area continuum mapping data done by e.g., bolometric arrays on Herschel which lack of dynamic and kinematic information, or science that require large area high spatial and spectral resolution. Improving mapping speed entails increasing the number of detectors and/or enhancing sensitivity. However, most existing sub-mm instruments fall short of reaching the ultimate quantum limit, crucial for imaging high-z galaxies and black holes. Additionally, these instruments often possess a limited number of spatial pixels, making mapping large structure within the Galactic plane and nearby galaxies a formidable challenge.A new generation of ultra-sensitive wide-field infrastructure is now required e.g., the planned ground-based (e.g., AtLAST, LST) and space-based (e.g., NASA Probe) telescopes, that are expected to be equipped with large pixel count heterodyne arrays (~103 pixels) and must be built whilst retaining extraordinary levels of individual-pixel sensitivity. It is only possible to plan the construction of large instruments with confidence, once the needed technology has been developed to high TRL, including smaller-scale demonstration on existing telescopes. This D.Phil. project therefore aim to address these challenges by developing a small-pixel count sub-millimetre heterodyne array, involving advancing techniques at every stage, making them modular and array-able, with an eye towards enabling the future deployment of kilo-pixel receivers. The project targets to demonstrate the technologies by developing a dual-polarisation sub-millimetre heterodyne demonstrator, which would retain the full astronomical signal strength and preserve the polarisation information. For the scientific observation part, the student will focus on an investigation of the Interstellar Medium of a sample of nearby galaxies using data from the James Webb Space Telescope (JWST) Mid-Infrared Spectrometer (MIRI) and the Atacama Large Millimetre Array (ALMA). The advent of JWST has provided us with unprecedented sensitivity and spatial resolution to enable studies of the properties of the ISM in a spatially resolved manner in galaxies near and far. The project will focus on a sample of nearby galaxies and will examine, for the first time, element abundances based on mid-infrared (MIR) ionic lines which are unaffected by temperature dependencies and therefore will deliver robust estimates of metallicity gradients. Furthermore, the student will compare the distribution of molecular gas (often used to trace the raw ma

这位菲尔博士。该计划由两个互补的科学主题组成：重点是亚毫米量子探测器的开发，以及利用来自 JWST 和 ALMA 的中红外 (MIR) 数据的观测项目。恒星形成区域的物理和化学条件可以是通过在毫米和亚毫米波长下观察来确定，在这些波长下可以找到大量原子、离子和分子谱线。近年来，对这些谱线的光谱和干涉观测完善了我们对附近和遥远星系的气体动力学和运动学的了解，并首次实现了黑洞图像的直接探测。这些观测之所以成为可能，是因为近量子噪声限制的超导体-绝缘体-超导体（SIS）外差接收器具有非凡的特性。 SIS 混频器通常用于北方扩展毫米波阵列 (NOEMA)、阿塔卡马大型毫米波/亚毫米波阵 (ALMA) 和赫歇尔空间天文台等天文台，可对高亮度微弱天体进行大量观测。光谱和空间分辨率。然而，利用 SIS 接收器进行近期天文观测（无论是地面观测还是星载观测）都存在重大限制。传统的高光谱分辨率观测需要过多的望远镜时间。这阻碍了重要的科学计划，特别是在补充由缺乏动态和运动学信息的赫歇尔辐射热阵列等完成的大面积连续测绘数据时，或需要大面积高空间和光谱分辨率的科学时。提高绘图速度需要增加探测器的数量和/或提高灵敏度。然而，大多数现有的亚毫米级仪器都未能达到最终的量子极限，而这对于高z星系和黑洞的成像至关重要。此外，这些仪器通常拥有有限数量的空间像素，使得绘制银河平面和附近星系内的大型结构成为一项艰巨的挑战。现在需要新一代的超灵敏宽场基础设施，例如计划中的地面（例如，AtLAST、LST）和天基（例如 NASA Probe）望远镜，预计将配备大像素数外差阵列（约 103 像素），并且必须在建造时保留非凡的性能各个像素的灵敏度水平。只有当所需的技术发展到高TRL（包括在现有望远镜上进行小规模演示）时，才有可能充满信心地规划大型仪器的建造。这位菲尔博士。因此，该项目旨在通过开发小像素数亚毫米外差阵列来应对这些挑战，涉及每个阶段的先进技术，使其模块化和可阵列化，着眼于实现千像素接收器的未来部署。该项目的目标是通过开发双偏振亚毫米外差演示器来演示这些技术，该演示器将保留完整的天文信号强度并保留偏振信息。对于科学观测部分，学生将重点利用詹姆斯·韦伯太空望远镜 (JWST) 中红外光谱仪 (MIRI) 和阿塔卡马大型毫米波阵列 (ALMA) 的数据对附近星系样本的星际介质进行调查。 JWST 的出现为我们提供了前所未有的灵敏度和空间分辨率，使我们能够以空间分辨率的方式研究近处和远处星系中 ISM 的特性。该项目将重点关注附近星系的样本，并将首次检查基于中红外（MIR）离子线的元素丰度，该离子线不受温度依赖性的影响，因此将提供金属丰度梯度的可靠估计。此外，学生将比较分子气体的分布（通常用于追踪原始气体）