First-Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Tests of Gaussianity
First-Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Tests of Gaussianity
复制标题
DOI：
10.1086/377220
复制
发表时间：
2003-02
期刊：
影响因子：
--
通讯作者：
E. Komatsu;A. Kogut;M. Nolta;C. Bennett;M. Halpern;G. Hinshaw;N. Jarosik;M. Limon;S. Meyer;L. Page;D. Spergel;G. Tucker;L. Verde;Edward J. Wollack;E. L. W. Princeton;Nasa Gsfc;Ubc;U. Chicago;Brown;Ucla
中科院分区：
文献类型：
--
作者：
E. Komatsu;A. Kogut;M. Nolta;C. Bennett;M. Halpern;G. Hinshaw;N. Jarosik;M. Limon;S. Meyer;L. Page;D. Spergel;G. Tucker;L. Verde;Edward J. Wollack;E. L. W. Princeton;Nasa Gsfc;Ubc;U. Chicago;Brown;Ucla
我们提出了 WMAP 1 年宇宙微波背景天空图中非高斯原初涨落幅度的限制。非线性耦合参数 fNL 表征原初势中二次项的幅度。我们使用两种统计量：一种是三次统计量，它在组合角双谱的所有配置后测量温度波动的相位相关性。另一个使用闵可夫斯基泛函来测量天空图的形态。两种方法都发现 WMAP 数据与高斯原始波动一致，并在 95% 置信度下建立限制，-58 < fNL < 134。 fNL 不存在明显的频率或尺度依赖性。 WMAP 极限比 COBE 好 30 倍，验证了功率谱可以高度准确地全面表征 WMAP 数据中 CMB 各向异性的统计特性。我们的结果还验证了使用高斯理论来预测局部宇宙中星团的丰度。我们检测到 41 GHz 处的点源对双谱的贡献，bsrc = (9.5 ± 4.4) × 10-5 μK3 sr2，这给出了 csrc = (15 ± 6) × 10-3 μK2 sr 点源的功率谱（以热力学温度单位表示）。该值与源数量计数和 41 GHz 功率谱的独立估计非常吻合，表明 bsrc 直接测量剩余源贡献。
We present limits to the amplitude of non-Gaussian primordial fluctuations in the WMAP 1 yr cosmic microwave background sky maps. A nonlinear coupling parameter, fNL, characterizes the amplitude of a quadratic term in the primordial potential. We use two statistics: one is a cubic statistic which measures phase correlations of temperature fluctuations after combining all configurations of the angular bispectrum. The other uses the Minkowski functionals to measure the morphology of the sky maps. Both methods find the WMAP data consistent with Gaussian primordial fluctuations and establish limits, -58 < fNL < 134, at 95% confidence. There is no significant frequency or scale dependence of fNL. The WMAP limit is 30 times better than COBE and validates that the power spectrum can fully characterize statistical properties of CMB anisotropy in the WMAP data to a high degree of accuracy. Our results also validate the use of a Gaussian theory for predicting the abundance of clusters in the local universe. We detect a point-source contribution to the bispectrum at 41 GHz, bsrc = (9.5 ± 4.4) × 10-5 μK3 sr2, which gives a power spectrum from point sources of csrc = (15 ± 6) × 10-3 μK2 sr in thermodynamic temperature units. This value agrees well with independent estimates of source number counts and the power spectrum at 41 GHz, indicating that bsrc directly measures residual source contributions.