论文标题
在低频下从地面检测CMB B模型
On the Detection of CMB B-modes from Ground at Low Frequency
论文作者
论文摘要
原始的CMB $ B $模式搜索是科学界的焦点,因为原始信号中编码的大量宇宙学信息。但是,从数据分析的角度来看,由于与前景相比的相对低振幅,镜头污染来自$ e $码的泄漏和仪器噪声,因此对该信号的检测具有挑战性。在这里,我们研究了原始极化$ b $ mode检测的可行性,其在微波炉低频制度中运行的地面望远镜(即,从10GHz-1220GHz)在几个不同的情况下:i。仪器的通道分布和噪音,ii。考虑到不同可能的$ r $值和删除程度的张量与量表比($ r $)的可检测性,iii。包括偏振异常微波发射(AME)的可能来源的效果,IV。不同观察策略的优势和劣势以及v。大气和系统的噪声对恢复的影响。我们主要集中于去除银河前景以及噪声污染,通过应用基于全参数像素的最大似然成分分离技术。此外,我们开发了一种数值方法来估计组件分离后留下的残差功率谱,这使我们能够减轻原始$ b $ mode功率谱重建中引入的可能偏差。在许多其他结果中,我们发现这种实验能够检测Starobinsky的$ r $,即使没有执行删除,或者考虑了可能的两极分化AME贡献。此外,我们表明该实验是对其他在地面或卫星任务(例如Litebird)的有力补充,因为它可以极大地帮助低频前景表征。
The primordial CMB $B$-mode search is on the spotlight of the scientific community due to the large amount of cosmological information that is encoded in the primeval signal. However, the detection of this signal is challenging from the data analysis point of view, due to the relative low amplitude compared to the foregrounds, the lensing contamination coming from the leakage of $E$-modes, and the instrumental noise. Here, we studied the viability of the detection of the primordial polarization $B$-mode with a ground-based telescope operating in the microwave low-frequency regime (i.e., from 10GHz-120GHz) in a handful of different scenarios: i. the instrument's channels distribution and noise, ii. the tensor-to-scalar ratio ($r$) detectability considering different possible $r$ values and degrees of delensing, iii. the effect of including a possible source of polarized anomalous microwave emission (AME), iv. the strengths and weaknesses of different observational strategies and, v. the atmospheric and systematic noise impact on the recovery. We focused mainly on the removal of galactic foregrounds as well as noise contamination by applying a full-parametric pixel-based maximum likelihood component separation technique. Moreover, we developed a numerical methodology to estimate the residuals power spectrum left after component separation, which allow us to mitigate possible biases introduced in the primordial $B$-mode power spectrum reconstruction. Among many other results, we found that this sort of experiment is capable of detecting Starobinsky's $r$ even when no delensing is performed or, a possible polarized AME contribution is taken into account. Besides, we showed that this experiment is a powerful complement to other on-ground or satellite missions, such as LiteBIRD, since it can help significantly with the low-frequency foregrounds characterization.