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arXiv 0901.4540astro-ph.CO
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用宇宙背景成像仪对30 GHz CMB强度进行5年测量的宇宙学结果

Cosmological Results from Five Years of 30 GHz CMB Intensity Measurements with the Cosmic Background Imager

J. L. Sievers, B. S. Mason, L. Weintraub, C. Achermann, P. Altamirano, J. R. Bond, L. Bronfman, R. Bustos, C. Contaldi, C. Dickinson, M. E. Jones, J. May, S. T.… 展开作者

J. L. Sievers, B. S. Mason, L. Weintraub, C. Achermann, P. Altamirano, J. R. Bond, L. Bronfman, R. Bustos, C. Contaldi, C. Dickinson, M. E. Jones, J. May, S. T. Myers, N. Oyarce, S. Padin, T. J. Pearson, M. Pospieszalski, A. C. S. Readhead, R. Reeves, M. C. Shepherd, A. C. Taylor, S. Torres

摘要:

我们目前的角功率谱的总强度各向异性的CMB从CBI的最终结果。我们的分析包括2000年1月至2005年4月收集的所有原始各向异性数据,并从改进的极大似然分析管道中受益匪浅。它还包括从一个30千兆赫的前景调查进行的绿岸望远镜(GBT)的地方,由于前景点源的可能污染的显着限制的结果。我们改进了以前的CBI结果的阻尼尾部约两个因素。这些数据证实,在~3-sigma,在小角度尺度(l > 1800)上存在超过固有CMB各向异性的过剩功率。使用GBT调查,我们发现目前已知的射电源群无法产生功率;需要一个新的微弱源群,其光谱指数急剧上升,以解释源的过剩。我们还提出了一个完整的宇宙学参数分析的新的CBI功率谱。单独使用CBI时,全参数分析发现,超出σ_8 =0.8宇宙的预期水平1.6 σ。我们发现,除了高-l CMB数据大大提高了宇宙弦的TT功率谱的贡献,以及运行的标量谱指数的约束…我们还提出了预测其他实验应该看到在不同的频率和角分辨率给定的CBI观察到的多余的权力。我们发现,从目前的高分辨率CMB测辐射热计实验报告的高-l带功率是一致的,彼此和CBI,如果多余的功率是由于在CBI水平的2.5 +/-1倍的σ_8 =0.8标准SZ模板的SZE。<Abridged>

英文摘要:

We present final results on the angular power spectrum of total intensity anisotropies in the CMB from the CBI. Our analysis includes all primordial anisotropy data collected between January 2000 and April 2005, and benefits significantly from an improved maximum likelihood analysis pipeline. It also includes results from a 30 GHz foreground survey conducted with the Green Bank Telescope (GBT) which places significant constraints on the possible contamination due to foreground point sources. We improve on previous CBI results by about a factor of two in the damping tail. These data confirm, at ~3-sigma, the existence of an excess of power over intrinsic CMB anisotropy on small angular scales (l > 1800). Using the GBT survey, we find currently known radio source populations are not capable of generating the power; a new population of faint sources with steeply rising spectral indices would be required to explain the excess with sources... We also present a full cosmological parameter analysis of the new CBI power spectrum... With CBI alone, the full parameter analysis finds the excess is 1.6-sigma above the level expected for a sigma_8=0.8 universe. We find the addition of high-l CMB data substantially improves constraints on cosmic string contributions to the TT power spectrum as well as the running of the scalar spectral index... We also present forecasts for what other experiments should see at different frequencies and angular resolutions given the excess power observed by CBI. We find that the reported high-l bandpowers from current high resolution CMB bolometer experiments are consistent with each other and CBI if the excess power is due to the SZE at the CBI-level of 2.5 +/- 1 times the sigma_8=0.8 standard SZ template. <Abridged>

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