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arXiv 1202.0546astro-ph.CO
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用South Pole望远镜数据测量微波背景的引力透镜

A measurement of gravitational lensing of the microwave background using South Pole Telescope data

A. van Engelen, R. Keisler, O. Zahn, K. A. Aird, B. A. Benson, L. E. Bleem, J. E. Carlstrom, C. L. Chang, H. M. Cho, T. M. Crawford, A. T. Crites, T. de Haan, M… 展开作者

A. van Engelen, R. Keisler, O. Zahn, K. A. Aird, B. A. Benson, L. E. Bleem, J. E. Carlstrom, C. L. Chang, H. M. Cho, T. M. Crawford, A. T. Crites, T. de Haan, M. A. Dobbs, J. Dudley, E. M. George, N. W. Halverson, G. P. Holder, W. L. Holzapfel, S. Hoover, Z. Hou, J. D. Hrubes, M. Joy, L. Knox, A. T. Lee, E. M. Leitch, M. Lueker, D. Luong-Van, J. J. McMahon, J. Mehl, S. S. Meyer, M. Millea, J. J. Mohr, T. E. Montroy, T. Natoli, S. Padin, T. Plagge, C. Pryke, C. L. Reichardt, J. E. Ruhl, J. T. Sayre, K. K. Schaffer, L. Shaw, E. Shirokoff, H. G. Spieler, Z. Staniszewski, A. A. Stark, K. Story, K. Vanderlinde, J. D. Vieira, R. Williamson

摘要:

我们使用南极望远镜从2008年和2009年的数据,以检测非高斯签名的宇宙微波背景(CMB)产生的引力透镜和测量的功率谱的投影引力势。我们约束的透镜信号的测量振幅的基准LCDM宇宙学模型中预期的比率为0.86 +/- 0.16,在6.3西格玛没有不利的透镜。在WMAP 7所允许的LCDM宇宙学模型上边缘化的结果是A_lens=0.90+/-0.19,表明CMB透镜探测的红移范围0.5 <~ z <~ 5的物质涨落幅度与预测吻合得很好。我们提出了几个一致性检查的结果。这些包括在经滤波以在傅立叶空间中没有重叠的CMB图中的透镜特征的清楚检测,以及与LCDM预期的信号一致的“卷曲”诊断。我们进行了详细的研究,由于噪声,前景和其他影响的测量偏差,并确定这些贡献是相对较小的统计测量中的不确定性相比。我们将这种透镜测量与WMAP 7的结果相结合,以改善对宇宙学参数的约束:我们发现宇宙空间曲率的测量改善了3.9倍,Omega_k=-0.0014+/-0.0172; LCDM内物质波动幅度提高10%,σ_8 =0.810+/ 0.026;暗能量状态方程提高5%,w=-1.04+/-0.40。当与WMAP 7和哈勃参数的外部约束相结合提供的w测量值相比时,增加透镜数据将w的测量值提高了15%,得到w=-1.087+/-0.096。

英文摘要:

We use South Pole Telescope data from 2008 and 2009 to detect the non-Gaussian signature in the cosmic microwave background (CMB) produced by gravitational lensing and to measure the power spectrum of the projected gravitational potential. We constrain the ratio of the measured amplitude of the lensing signal to that expected in a fiducial LCDM cosmological model to be 0.86 +/- 0.16, with no lensing disfavored at 6.3 sigma. Marginalizing over LCDM cosmological models allowed by the WMAP7 results in a measurement of A_lens=0.90+/-0.19, indicating that the amplitude of matter fluctuations over the redshift range 0.5 <~ z <~ 5 probed by CMB lensing is in good agreement with predictions. We present the results of several consistency checks. These include a clear detection of the lensing signature in CMB maps filtered to have no overlap in Fourier space, as well as a "curl" diagnostic that is consistent with the signal expected for LCDM. We perform a detailed study of bias in the measurement due to noise, foregrounds, and other effects and determine that these contributions are relatively small compared to the statistical uncertainty in the measurement. We combine this lensing measurement with results from WMAP7 to improve constraints on cosmological parameters when compared to those from WMAP7 alone: we find a factor of 3.9 improvement in the measurement of the spatial curvature of the Universe, Omega_k=-0.0014+/-0.0172; a 10% improvement in the amplitude of matter fluctuations within LCDM, sigma_8=0.810+/ 0.026; and a 5% improvement in the dark energy equation of state, w=-1.04+/-0.40. When compared with the measurement of w provided by the combination of WMAP7 and external constraints on the Hubble parameter, the addition of the lensing data improve the measurement of w by 15% to give w=-1.087+/-0.096.

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