High Resolution Observations of the Cosmic Microwave Background (CMB) with Arcminute Cosmology Bolometer Array Receiver (ACBAR)

本提案寻求继续支持Arcminute宇宙学辐射热计阵列接收器（ACBAR）的观测。ACBAR是一个16个元件的230 mk辐射热计接收器，设计用于在3毫米波长波段产生高分辨率的CMB图像。ACBAR安装在南极2.1米的蝰蛇望远镜上，它的灵敏度可以与气球实验相媲美，而且它的角度分辨率是气球实验无法企及的。ACBAR充分利用南极南极冬季优越的大气条件，正在拍摄宇宙微波背景辐射的图像，其灵敏度和分辨率甚至超过了拟议中的普朗克卫星的能力。对CMB的观测为早期宇宙提供了一个独特的窗口；这些数据在将宇宙学转变为精确科学的过程中发挥了关键作用。特别是，宇宙微波背景的小角度尺度观测是一个新的领域，对它的了解相对较少。在这些角度尺度上，由中间结构引入的次生各向异性的贡献预计将占主导地位。例如，被星系团束缚的热气体散射的光子会导致CMB的光谱扭曲，这被称为sunyev - zeldovich （SZ）效应。对SZ效应的观测可以为宇宙结构的增长理论提供重要的新约束。ACBAR的独特功能使它能够解决广泛的科学问题，重点是测量CMB的主要和次要各向异性。ACBAR于2000年12月部署到南极，此后一直在运作。2003年冬季的后半段和2004年的整个季节将专门用于ACBAR的观测。所要求的18个月对ACBAR观测和结果数据分析的支持将有助于充分发挥这一独特强大的宇宙学研究仪器的潜力。获此建议支持的4个机构将继续在ACBAR和Viper的维护和操作方面进行合作，并参与数据分析。ACBAR的结果将作为大规模MAP航天器数据集的重要补充，并为单频BIMA和CBI实验报告的精细尺度过剩功率提供必要的检查。为ACBAR开发的新型仪器、观测技术和分析通常适用于未来的地面毫米天文实验。该项目已为7名以上的本科生提供了实践研究经验，并将成为4名研究生的论文。

This proposal seeks continued support for observations with the Arcminute Cosmology Bolometer Array Receiver (ACBAR). ACBAR is a 16 element 230-mK bolometer receiver designed to produce high resolution images of the CMB in three mm wavelength bands. Mounted on the 2.1m Viper telescope at the South Pole, ACBAR has sensitivity that rivals balloon-borne experiments and angular resolution that they cannot hope to achieve. Making full use of the excellent atmospheric conditions in the Austral winter at the South Pole, ACBAR is producing images of the Cosmic Microwave Background (CMB) radiation with sensitivity and resolution that exceed the capabilities of even the proposed Planck satellite. Observations of the CMB provide a unique window to the early Universe; these data play a key role in the transformation of Cosmology to a precise science. In particular, small angular scale observations of the CMB are a new frontier about which comparatively little is known. On these angular scales, contributions from secondary anisotropies introduced by intervening structure are expected to become dominant. For example, the scattering of photons by hot gas bound to clusters of galaxies results in a spectral distortion of the CMB known as the Sunyeav-Zeldovich (SZ) effect. Observations of the SZ effect can provide important new constraints on theories of the growth of Universe's structure. The unique capabilities of ACBAR allow it to address a broad range of science focused on measuring the primary and secondary anisotropies of the CMB. ACBAR was deployed to the South Pole in December 2000 and has been operating since. The second half of the winter of 2003 and the entire 2004 season will be dedicated to observations with ACBAR. The requested 18 months of support for observations with ACBAR and analysis of the resulting data will help to realize the full potential of this uniquely powerful instrument for the study of cosmology. The four institutions supported by this proposal will continue to collaborate in the maintenance and operation of ACBAR and Viper, and participate in the analysis of the data. The results from ACBAR will serve as a vital complement to the large-scale MAP spacecraft dataset, and provide an essential check of the fine-scale excess power reported by the single frequency BIMA and CBI experiments. The novel instrumentation, observation techniques, and analysis developed for ACBAR are generally applicable to future ground based millimeter astronomy experiments. This project has provided hands on research experience to more than seven undergraduate students and will result in the theses of four graduate students.