A hybrid map-C l component separation method for primordial CMB B-mode searches
A hybrid map-C l component separation method for primordial CMB B-mode searches
复制标题
原始CMB B模式搜索的混合map-C l分量分离方法
DOI：
10.1088/1475-7516/2023/03/035
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发表时间：
2023
影响因子：
6.4
通讯作者：
Azzoni S
中科院分区：
文献类型：
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作者：
Azzoni S
未来地基和星载实验对宇宙微波背景（CMB）偏振发射的观测有望间接探测大规模 B 模式偏振形式的原始张量波动中难以捉摸的信号。然而，这样做需要将信号与极化的银河系前景准确而稳健地分离。我们提出了一种用于多频 CMB 观测的分量分离方法，该方法结合了基于地图和基于功率谱的技术的一些优点，并且直接适用于存在真实前景和仪器噪声的数据。我们证明，对于具有不同复杂程度的各种前景模型，该方法能够将银河系前景的污染降低到等效张量与标量之比 r FG≲ 5× 10-4 以下，满足下一代天文台的要求。这种偏差的减少与最终统计不确定性轻微增加约 20-30% 相关，并且适用于大的天空区域以及针对 B 模式功率谱中的再电离和复合凸点的实验。
The observation of the polarised emission from the Cosmic Microwave Background (CMB) from future ground-based and satellite-borne experiments holds the promise of indirectly detecting the elusive signal from primordial tensor fluctuations in the form of large-scale B-mode polarisation. Doing so, however, requires an accurate and robust separation of the signal from polarised Galactic foregrounds. We present a component separation method for multi-frequency CMB observations that combines some of the advantages of map-based and power-spectrum-based techniques, and which is direcly applicable to data in the presence of realistic foregrounds and instrumental noise. We demonstrate that the method is able to reduce the contamination from Galactic foregrounds below an equivalent tensor-to-scalar ratio r FG≲ 5× 10-4, as required for next-generation observatories, for a wide range of foreground models with varying degrees of complexity. This bias reduction is associated with a mild∼ 20–30% increase in the final statistical uncertainties, and holds for large sky areas, and for experiments targeting both the reionisation and recombination bumps in theB-mode power spectrum.