SO:UK - A major UK contribution to the Simons Observatory

在过去的三十年里，对宇宙微波背景(CMB)的测量一直是建立标准宇宙学模型的推动力。英国科学家发挥了关键作用，特别是在最近，他们在欧空局的普朗克任务中发挥了重要作用。这些进展非常重要，但CMB对基础物理学的最大贡献很可能还没有到来。未来CMB实验的主要科学目标包括(I)搜索CMB极化场中大角度尺度的旋度或“B模”波动，揭示暴胀产生的原始引力波的特征，(Ii)通过在CMB小角尺度上的波动印记来寻找超出标准模型的新的轻遗迹粒子，(Iii)利用对CMB引力透镜和Sunyaev-Zel‘dovich(SZ)效应的测量来约束中微子质量的总和，以及(Iv)利用CMB透镜和SZ测量的低红移探测器帮助理解观测到的宇宙加速膨胀。未来实验的高灵敏度和高角度分辨率也将促进广泛的额外前沿科学的发展，从研究电离时代到寻找更多的太阳系物体。西蒙斯天文台(SO)是一个由美国牵头的国际项目，目的是在智利北部的阿塔卡马沙漠建造一组CMB望远镜。它的设计是为了应对这些新的科学挑战，并将于2023年开始运行。在这里，我们提出了英国的一项主要贡献，由三个主要组成部分组成。首先，我们将建立一个总部设在英国的数据中心，该中心将在提供所有SO望远镜的主要数据产品方面发挥主导作用。其次，我们将推行一项算法开发工作计划，为SO数据管道软件基础设施做出重大贡献。我们计划的第三部分是为SO大口径望远镜提供单一的超高频(UHF)光管。交付数据中心以及数据管道所需的算法和处理功能，将满足SO项目中的一个关键需求，并将SO定位为英国科学家在随后的重大科学开发中发挥主导作用的最佳选择。设在英国的数据中心还将有助于(由更广泛的英国宇宙学和天体物理界)结合来自其他英国旗舰天文项目的数据对SO数据进行联合分析，这些项目包括欧几里德卫星、维拉鲁宾天文台和平方公里阵列。SO：UK仪器包括关键技术的开发和演示，包括动力学电感探测器(KIDS)和超材料(MM)准光学元件。作为2020年代领先的CMB实验的一部分，展示这些由英国驱动的技术的令人信服的优势将成为CMB未来项目(包括CMB-S4实验和未来可能由欧空局领导的卫星任务)以及其他银河系外天文和宇宙学高调领域的未来项目中采用这些技术的有力论据。

During the last three decades, measurements of the Cosmic Microwave Background (CMB) have been the driving force in establishing the standard cosmological model. UK scientists have played a pivotal role, particularly in recent times with major roles in ESA's Planck mission. These advances have been hugely important but the CMB's greatest contributions to fundamental physics could well be yet to come. The primary science goals of future CMB experiments include (i) the search for curl or ``B-mode" fluctuations on large angular scales in the CMB polarisation field, a tell-tale signature of primordial gravitational waves from inflation, (ii) to search for new light relic particles beyond the Standard Model through their imprint on the CMB fluctuations on small angular scales, (iii) to use measurements of the gravitational lensing and Sunyaev-Zel'dovich (SZ) effects in the CMB to constrain the sum of the neutrino masses and (iv) to help understand the observed accelerated expansion of the Universe using the low-redshift probes of CMB lensing and SZ measurements. The high sensitivity and high angular resolution of future experiments will also facilitate a wide range of additional frontier science ranging from studies of the reionisation era to searching for additional solar system objects. Simons Observatory (SO) is a US-led international project to construct a group of CMB telescopes in the Atacama Desert in northern Chile. It has been designed to address these new science challenges, and is due to begin operations in 2023. Here we propose a major UK contribution, composed of three main components. Firstly, we will establish a UK-based data centre, which will play a lead role in delivering the primary data products from all of the SO telescopes. Secondly, we will pursue a program of algorithm development work, forming a major contribution to the SO data pipeline software infrastructure. The third strand of our programme is the provision of a single ultra-high-frequency (UHF) optics tube for the SO Large Aperture Telescope.Delivering the data centre, and the algorithms and processing functions needed for the data pipeline, will address a critical need within the SO project and will position SO:UK scientists optimally for taking lead roles in the subsequent headline science exploitation of the SO data. The UK-based data centre will also help facilitate joint analyses (by the wider UK cosmology and astrophysics community) of the SO data in combination with data from other flagship UK astronomy projects, including the Euclid satellite, the Vera Rubin Observatory and the Square Kilometre Array. The SO:UK instrument includes the development and demonstration of key technologies including Kinetic Inductance Detectors (KIDs) and meta-material (MM) quasi-optical components. Demonstrating the compelling advantages of these UK-driven technologies as part of the leading CMB experiment of the 2020s will be a powerful argument for their adoption in future CMB projects (including the ground-based CMB-S4 experiment and a possible future ESA-led satellite mission) as well as in future projects in other high-profile areas of extra-Galactic astronomy and cosmology.