Mitigating Complex Dust Foregrounds in Future Cosmic Microwave Background Polarization Experiments
Mitigating Complex Dust Foregrounds in Future Cosmic Microwave Background Polarization Experiments
复制标题
减轻未来宇宙微波背景偏振实验中的复杂尘埃前景
DOI：
10.3847/1538-4357/aaa489
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发表时间：
2017
期刊：
影响因子：
--
通讯作者：
P. Bull
中科院分区：
文献类型：
--
作者：
B. Hensley;P. Bull
在测量宇宙微波背景辐射（CMB）的B模式偏振时，偏振银河前景是系统误差的主要来源之一。实验对标准参数模型无法捕获的前景频谱的复杂性变得越来越敏感，这可能会影响我们有效分离这些成分的能力。采用一套尘埃模型，包括各种物理效应，我们模拟观测未来的七波段CMB实验，以评估这些复杂性对参数组件分离的影响。我们确定配置的频带，最大限度地减少了“模型误差”所造成的拟合简单的参数模型，更复杂的“真正的”前景光谱，其中偏置推断CMB信号。我们发现：（a）采用简单的双参数修正黑体（MB B）灰尘模型的拟合在存在物理上真实的灰尘前景的情况下倾向于在恢复的偏振CMB信号中产生显著的偏差;（B）具有三个附加参数的广义MB B模型在大多数情况下减小了这种偏差，但是不可忽略的偏差可能仍然存在，并且可能难以检测;（c）引起频率去相关的视线效应和铁颗粒的存在是用于恢复真实CMB信号的尘埃排放中最成问题的复杂性。需要更复杂的模拟来证明未来的CMB实验可以成功地减轻这些物理上更真实的尘埃前景。
Polarized Galactic foregrounds are one of the primary sources of systematic error in measurements of the B-mode polarization of the cosmic microwave background (CMB). Experiments are becoming increasingly sensitive to complexities in the foreground frequency spectra that are not captured by standard parametric models, potentially affecting our ability to efficiently separate out these components. Employing a suite of dust models encompassing a variety of physical effects, we simulate observations of a future seven-band CMB experiment to assess the impact of these complexities on parametric component separation. We identify configurations of frequency bands that minimize the “model errors” caused by fitting simple parametric models to more complex “true” foreground spectra, which bias the inferred CMB signal. We find that: (a) fits employing a simple two-parameter modified blackbody (MBB) dust model tend to produce significant bias in the recovered polarized CMB signal in the presence of physically realistic dust foregrounds; (b) generalized MBB models with three additional parameters reduce this bias in most cases, but non-negligible biases can remain, and can be hard to detect; (c) line-of-sight effects, which give rise to frequency decorrelation, and the presence of iron grains are the most problematic complexities in the dust emission for recovering the true CMB signal. More sophisticated simulations will be needed to demonstrate that future CMB experiments can successfully mitigate these more physically realistic dust foregrounds.
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影响因子：
4.8
作者：
B. Thorne;J. Dunkley;D. Alonso;S. Naess
通讯作者：
B. Thorne;J. Dunkley;D. Alonso;S. Naess
影响因子：
4.9
作者：
Hensley, Brandon S.;Draine, B. T.
通讯作者：
Draine, B. T.
影响因子：
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作者：
Altobelli, N.;Postberg, F.;Gruen, E.
通讯作者：
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DOI：
10.2172/1352047
发表时间：
2016-10
期刊：
--
影响因子：
--
作者：
K. Abazajian;Peter Adshead;Z. Ahmed;S. Allen;D. Alonso;K. Arnold;C. Baccigalupi;J. Bartlett;
通讯作者：
K. Abazajian;Peter Adshead;Z. Ahmed;S. Allen;D. Alonso;K. Arnold;C. Baccigalupi;J. Bartlett;
影响因子：
8.6
作者：
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通讯作者：
Yoon, K. W.