论文标题
Planck 2018 CMB极化图的比较
Comparison of the Planck 2018 CMB polarization maps in the BICEP2/Keck region
论文作者
论文摘要
我们使用一个点分布函数（1PDF），偏度和峰度统计量检验了Planck 2018中极化图的统计特性。我们的分析是针对Q和U Stokes参数以及CMB信号的相应的E-和B模型进行的。我们通过研究CMB极化图与残留图（完整信号和CMB图之间的差异）之间的相关性来扩展我们的分析，该频率范围在Q/U和E/B方法的频率范围内。尽管所有CMB地图均显示了Q/U和E/B域几乎显示高斯统计属性，但对于指挥官地图的剩余物，剩余物的交叉相关性非常明显，指挥官地图的水平为$3.7σ$，NILC的nilc均为$5.2σ$。使用不包含宇宙学信号的NILC-命令差，我们在Q偏度和峰度中发现了一个亚持有的非高斯组件，分别为$4.3σ$和$10σ$。对于B模式，我们发现NILC/Commander Maps和143 GHz总信号之间的互相关水平很高（0.63--0.69），这与宇宙学成分无法相关。这些强大的偏差表明，在距离银河平面很远的二头肌面积的2018 Planck CMB偏振图中存在前景，系统效应和组件分离的残余物。我们的分析还证明了Q/U域而不是E/B的可取性，因为由于过渡Q/U $ \ rightarrow $ e/b的非本地性，因此确定了派生的CMB信号的统计属性。
We examine the statistical properties of polarization maps from Planck 2018 within the patch of sky observed by the BICEP2/Keck experiment using the one point distribution function (1PDF), skewness, and kurtosis statistics. Our analysis is performed for the Q and U Stokes parameters and for the corresponding E- and B-modes of the CMB signals. We extend our analysis by studying the correlations between CMB polarization maps and residual maps (the difference between the full signal and the CMB map) for the frequency range of 100--217 GHz with both the Q/U and E/B approaches. Although all the CMB maps reveal almost Gaussian statistical properties for Q/U and E/B domains, we have detected very significant anomalies for cross-correlations with residuals at 100 GHz at the level of $3.7σ$ for the Commander map and $5.2σ$ for NILC, for both the Q and U parameters. Using the NILC--Commander difference, which does not contain a cosmological signal, we find a sub-dominant non-Gaussian component in Q skewness and kurtosis at the level of $4.3σ$ and $10σ$, respectively. For the B-mode we have found a very high level of cross-correlation (0.63--0.69) between the NILC/Commander maps and the 143 GHz total signal, which cannot be associated with the cosmological component. These strong deviations suggest that remnants of foregrounds, systematic effects, and component separation exist in the 2018 Planck CMB polarization maps in the BICEP2 sky area, which is far away from the Galactic plane. Our analysis also demonstrates the preferability of the Q/U domain over E/B for determination of the statistical properties of the derived CMB signals, due to non-locality of the transition Q/U $\rightarrow$ E/B.
