Cosmological Results from Five Years of 30 GHz CMB Intensity Measurements with the Cosmic Background Imager
Cosmological Results from Five Years of 30 GHz CMB Intensity Measurements with the Cosmic Background Imager
复制标题
使用宇宙背景成像仪进行五年 30 GHz CMB 强度测量的宇宙学结果
DOI：
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发表时间：
2009
期刊：
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通讯作者：
N. Oyarce
中科院分区：
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作者：
J. Sievers;Sergio N. Torres;P. Altamirano;A. Taylor;R. Reeves;M. Pospieszalski;M. Jones;L. Bronfman;C. Dickinson;C. Achermann;B. Mason;S. Myers;M. Shepherd;S. Padin;A. Readhead;J. May;J. Bond;L. Weintraub;T. Pearson;C. Contaldi;R. Bustos;N. Oyarce
我们给出了CBI在CMB中总强度各向异性的角功率谱的最终结果。我们的分析包括2000年1月至2005年4月期间收集的所有原始各向异性数据，并从改进的最大似然分析管道中受益匪浅。它还包括由绿岸望远镜（GBT）进行的30 GHz前景调查的结果，该调查对前景点源可能造成的污染进行了重大限制。我们在阻尼尾翼上对先前的CBI结果进行了大约两倍的改进。这些数据证实，在~3 σ，在小角尺度上（1 > 1800）存在超过CMB各向异性的功率过剩。使用GBT调查，我们发现目前已知的射电源群无法产生能量；需要一群新的光谱指数急剧上升的微弱源来解释源的过剩。我们还对新的CBI功率谱进行了完整的宇宙学参数分析。单独使用CBI，全参数分析发现，超出了sigma_8=0.8的宇宙预期水平的1.6西格玛。我们发现高l CMB数据的加入大大改善了宇宙弦对TT功率谱的贡献以及标量谱指数的运行的限制。我们还提出了其他实验在不同频率和角分辨率下应该看到的预测，考虑到CBI观察到的多余功率。在sigma_8=0.8标准SZ模板的2.5 +/- 1倍的CBI水平下，如果过量功率是由SZE引起的，则现有高分辨率CMB热辐射计实验报告的高带宽与CBI是一致的。
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.