Line intensity mapping at mm/sub-mm wavelengths: developing a new probe of cosmology

线强度测绘（LIM）是一种很有前途的观测技术，其应用范围涉及宇宙学和天体物理学的许多领域。空间分布和测量的红移特定发射线可以作为物质分布的基础的示踪剂，使我们能够在整个宇宙历史中建立大尺度结构的3D地图。存在一个广泛的光谱发射线，属于毫米/亚毫米波长范围内，提供多个独立的示踪剂，使我们的探针结构跨越红移范围的时代的再电离。卡迪夫的天文仪器组（AIG）在长波长仪器的开发方面享有盛誉，我们现在在许多关键实验中发挥着主导作用，包括西蒙天文台（SO）和南极望远镜（SPT）。该项目提供了一个机会，开发新的实验方法，需要实现毫米波长的LIM，以及领先的分析新的和最近的天空数据集与SPT。该项目的实验方面将侧重于开发一种新型的超导片上毫米波光谱仪，该光谱仪将针对下一代LIM调查进行优化。小尺寸，自然的可扩展性，和固有的检测器灵敏度都很好地匹配未来的毫米波LIM实验的需要。美国国际集团在超导探测器技术和毫米波仪器的开发方面处于世界领先地位，该项目利用了美国国际集团广泛的设施和能力，包括：低温低温测试设备，毫米/亚毫米准光学元件，以及通过AIG在化合物半导体研究所内的作用建立的一个新的最先进的纳米加工中心。卡迪夫参与了设计，建造，和部署的SPT夏季线强度映射器（SPT-SLIM），一个探路者实验，致力于证明片上光谱仪技术的适用性LIM。SPT-SLIM计划于2023年底部署，将在南方夏季进行观测，预计将提供新的丰富数据集。在整个博士期间，在该项目中，成功的候选人将有机会在分析和数据简化管道的开发和测试中发挥重要作用，这是建立毫米波LIM作为新的宇宙学观测的关键一步。

Line Intensity Mapping (LIM) is a promising observational technique with applications spanning many areas of cosmology and astrophysics. The spatial distribution and measured redshift specific emission lines serve as a tracer of the underlying of the distribution of matter that allows us to build 3D maps of large-scale structure throughout the history of the Universe. There exists a wide range of spectral emission lines that fall within the mm/sub-mm wavelength range, providing multiple independent tracers that allow us probe structure across a redshift range out to the epoch of reionisation. The Astronomy Instrumentation Group (AIG) at Cardiff has a long-standing reputation in the development of long-wavelength instrumentation and we are now playing leading roles in a number of key experiments, including the Simon's Observatory (SO) and the South Pole Telescope (SPT). This project provides an opportunity to develop new experimental approaches that are needed to realise LIM at mm wavelengths, as well as lead analysis of new and recent on-sky datasets taken with the SPT. The experimental aspect of this project will focus on the development of a new class of superconducting on-chip mm-wave spectrometers that will be optimised for the next generation of LIM surveys. The small size, natural scalability, and intrinsic detector sensitivity are all well matched to the needs of future mm-wave LIM experiments. The AIG is a world leader in the development of superconducting detector technologies and mm-wave instrumentation, and this project leverages the broad range of AIG facilities and capabilities including; low-temperature cryogenic test equipment, mm/sub-mm quasi-optical components, and a new state-of-the-art nanofabrication centre through the AIG's role within the Institute for Compound Semiconductors.Cardiff is involved in the design, construction, and deployment of the SPT Summertime Line Intensity Mapper (SPT-SLIM), a pathfinder experiment dedicated to demonstrating the suitability of on-chip spectrometer technology for LIM. Scheduled to deploy in late 2023, SPT-SLIM will observe during the austral summer and is expected to provide a new and rich dataset. Throughout the duration of this Ph.D. project, the successful candidate will have opportunities to undertake important roles in the development and testing of the analysis and data reduction pipeline, a critical step toward establishing mm-wave LIM as a new cosmological observable.