Analysis of Data from the ACBAR experiment

宇宙微波背景（CMB）的观测为早期宇宙提供了一个独特的窗口，在宇宙学向精确科学的转变中起着关键作用。CMB是研究宇宙的有力工具，但它还远未被充分利用。该提案寻求对Arcminute宇宙学辐射热计阵列接收器（ACBAR）数据继续分析的支持。ACBAR是一个16单元的230微开尔文辐射热计接收器，在阿蒙森-斯科特南极站2.1米的VIPER望远镜上运行。ACBAR充分利用南极南极冬季优越的大气条件，拍摄出了CMB图像，其灵敏度和分辨率都超过了目前气球和卫星望远镜的能力。ACBAR完成了最后一季的观测，并于2005年12月退役。从2001年到2003年的观测中，ACBAR制作了从南极可见的最低尘埃对比天空中100平方度以上的CMB波动的高分辨率地图。然而，在2004年和2005年的观测季节，ACBAR的天空覆盖范围是早期观测的三倍，包括在boomerang2003长时间飞行中拍摄的同一区域的深空图像。有了这些观测，将有可能交叉校准BOOMERanG、ACBAR和NASA的WMAP航天器实验，不确定度小于2%。为了充分发挥CMB观测的潜力来约束宇宙学参数（如运行光谱指数），这种均匀而精确的校准是必要的。所提议的工作的智力价值是多方面的。该提案将支持开发和实现用于分析大型地面CMB数据集的新算法。这些算法将直接适用于未来雄心勃勃的实验，如南极10米望远镜。对结果的全面解释需要对引力透镜效应和次级各向异性的影响进行精确的计算。本提案中概述的工作将支持三名研究生完成博士论文，并将继续让本科生研究人员参与创新研究。这项提议的工作将对宇宙学领域产生广泛的影响，因为它产生的测量结果对从事从暴胀到星系团演化等各种主题研究的更大的宇宙学团体至关重要。当与WMAP实验结果相结合时，ACBAR将提供精确的宇宙学参数约束，如暗物质密度、运行光谱指数和物质密度波动的大小。这些测量将在支持或反驳新兴的标准宇宙学模型方面发挥关键作用。ACBAR还将对次级各向异性（如遥远星系团的Sunyaev-Zel'dovich效应）提出令人兴奋的新限制，并且应该能够首次探测到CMB的引力透镜效应。通过这一努力，ACBAR将成为分析下一代实验结果的探路者。

Observations of the Cosmic Microwave Background (CMB) provide a unique window to the early Universe and are playing a key role in the transformation of Cosmology to a precise science. The CMB is a powerful tool for the study of the Universe that is still far from being fully exploited. This proposal seeks support for continued analysis of data from the Arcminute Cosmology Bolometer Array Receiver (ACBAR). ACBAR is a 16-element 230 microKelvin bolometer receiver that operated on the 2.1-m VIPER telescope at the Amundsen-Scott South Pole Station. Making full use of the excellent atmospheric conditions in the Austral winter at the South Pole, ACBAR has produced images of the CMB with sensitivity and resolution that exceed the capabilities of current balloon and satellite based telescopes. ACBAR accomplished it final season of observations and was decommissioned in December 2005. From the 2001-2003 observations, ACBAR produced high-resolution maps of the CMB fluctuations over a hundred square degrees of the lowest dust-contrast sky visible from the South Pole. However, during the 2004 and 2005 observational seasons, ACBAR tripled the sky coverage of earlier observations, including a deep image of same region of sky that was imaged in the long-duration balloon BOOMERanG 2003 flight. With these observations, it will be possible to cross-calibrate the BOOMERanG, ACBAR, and NASA's WMAP spacecraft experiments with an uncertainty of less than 2%. This uniform and precise calibration is necessary in order to realize the full potential of CMB observations to constrain cosmological parameters such as a running spectral index. The intellectual merit of the proposed work is multifaceted. This proposal will support the development and implementation of new algorithms for the analysis of large ground-based CMB datasets. These algorithms will be directly applicable to future ambitious experiments such as the South Pole 10-m Telescope. A full interpretation of the results requires a precise accounting of the effects of gravitational lensing and secondary anisotropies. The work outlined in this proposal will support the completion of PhD theses by three graduate students and will continue to involve undergraduate researchers in innovative research. The proposed work will have broad impact on the field of cosmology by producing measurements that are essential for the larger cosmology community engaged in the study of a diverse range of topics from inflation to the evolution of galaxy clusters. When combined with results from the WMAP experiment, ACBAR will provide precise constraints on cosmological parameters such as, dark matter density, running spectral index, and the size of matter density fluctuations. These measurements will play a key role in either supporting or refuting the emerging standard cosmological model. ACBAR will also place exciting new constraints on secondary anisotropies such as the Sunyaev-Zel'dovich effect from distant galaxy clusters, and should be able to make the first detection of gravitational lensing of the CMB. Through this effort, ACBAR will serve as a pathfinder for the analysis of the results form the next generation of experiments.