B -mode constraints from Planck low-multipole polarization data
B -mode constraints from Planck low-multipole polarization data
复制标题
来自普朗克低多极偏振数据的 B 模式约束
DOI：
10.1093/mnras/stac3321
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发表时间：
2023
影响因子：
4.8
通讯作者：
De Belsunce R
中科院分区：
文献类型：
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作者：
De Belsunce R
我们给出了用Planck卫星测量的大角度宇宙微波背景极化各向异性对原始B模的限制。为了去除银河系的偏振前景，我们使用了贝叶斯参数分量分离方法，将同步辐射模拟为幂定律，将热尘埃发射模拟为修正的黑体。该方法将前景清理中的不确定性传播到地图的噪声协方差矩阵中。我们构造了两种似然：(I)半解析的基于互谱的似然近似(Momento)，以及(Ii)精确的基于像素的偏振似然(PixLike)。由于基于交叉频谱，它在统计上不如PixLike强大，但对跨频率相关的系统误差不那么敏感。这两种可能性都给出了张量标量比r，与来自低多极(2≤ℓ<；30)普朗克极化数据的零一致。从全任务地图上，我们在K*≡0.05 MPC−1的枢轴等级上获得了0.05<；0.274 r0.05<；0.408的95%置信度，使用像素点。omento给出了定性上相似但较弱的95%置信限r0.05；0.408。
We present constraints on primordialBmodes from large-angular scale cosmic microwave background polarization anisotropies measured with thePlancksatellite. To remove Galactic polarized foregrounds, we use a Bayesian parametric component separation method, modelling synchrotron radiation as a power law and thermal dust emission as a modified blackbody. This method propagates uncertainties from the foreground cleaning into the noise covariance matrices of the maps. We construct two likelihoods: (i) a semi-analytical cross-spectrum-based likelihood-approximation scheme (momento), and (ii) an exact polarization-only pixel-based likelihood (pixLike). Sincemomentois based on cross-spectra, it is statistically less powerful thanpixLike, but is less sensitive to systematic errors correlated across frequencies. Both likelihoods give a tensor-to-scalar ratio,r, that is consistent with zero from low-multipole (2 ≤ ℓ < 30)Planckpolarization data. From full-mission maps, we obtainr0.05< 0.274 at 95 per cent confidence at a pivot scale ofk*≡ 0.05 Mpc−1, usingpixLike.momentogives a qualitatively similar but weaker 95 per cent confidence limit ofr0.05< 0.408.