An angular power spectrum analysis of the DRAO 1.4 GHz polarization survey: implications for CMB observations
An angular power spectrum analysis of the DRAO 1.4 GHz polarization survey: implications for CMB observations
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DRAO 1.4 GHz 极化测量的角功率谱分析：对 CMB 观测的影响
DOI：
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发表时间：
2006
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通讯作者：
P. Reich
中科院分区：
文献类型：
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作者：
L. Porta;C. Burigana;W. Reich;P. Reich
目标。本分析的目的是提高知识的银河系漫同步辐射，这限制了敏感的CMB各向异性测量的统计特性。方法.我们分析了新的DRAO 1.4 GHz极化调查与Stockert 1.4 GHz的总强度调查，并推导出角功率谱（APS）的总强度，极化发射，以及它们的互相关为整个调查和三个低强度区域。结果漫同步辐射的APS模型的幂律。对于E模和B模，在多极区~$[30，300]$发现了α sim [-3.0，-2.5]$的斜率，通过将这些结果外推到70 GHz，我们可以估计CMB各向异性的银河同步辐射污染，并且我们发现的结果与来自WMAP 3年数据的结果是一致的。在低强度区，当张量标量比T/S为0.5，同步辐射温度谱指数为0.5时，可以清楚地观察到宇宙学原始B模的峰值估计值-3美元。它的检测也可能为$T/S ga 0.005$和$eta sim-3，如果前景与CMB信号的分离可以达到~ 5 {-}10\%$的精度。对于TE模式，不包括$的掩码|B
m gal}| 5^{circ}$（用于$etasim -3.0$）或$|B
m gal}| le 20^{circ}$（for $etasim-2.8 $）足以使前景污染可忽略不计，从而证实WMAP有能力清楚地看到温度-偏振相关峰和反峰系列。
Aims. The aim of the present analysis is to improve the knowledge of the statistical properties of the Galactic diffuse synchrotron emission, which constrains sensitive CMB anisotropy measurements. Methods. We have analysed the new DRAO 1.4 GHz polarization survey together with the Stockert 1.4 GHz total intensity survey and derived the angular power spectra (APSs) of the total intensity, the polarized emission, and their cross-correlation for the entire surveys and for three low-intensity regions. Results. The APSs of the diffuse synchrotron emission are modelled by power laws. For the E and B modes, a slope of $alpha sim [-3.0,-2.5]$ for the multipole range ~$[30,300]$ is found. By the extrapolation of these results to 70 GHz, we can estimate the Galactic synchrotron contamination of CMB anisotropies, and we find results that are compatible with the ones coming from WMAP 3-yr data. In the low-intensity regions, the cosmological primordial B mode peak at $ell sim 100$ should be clearly observable for a tensor-to-scalar ratio $T/S ga 0.5$ and a synchrotron temperature spectral index $eta sim -3$. Its detection is also possible for $T/S ga 0.005$ and $eta sim -3$, in case a separation of the foreground from the CMB signal could be achieved with an accuracy of ~$5{-}10\%$. For the TE mode, a mask excluding $|b_{
m gal}| le 5^{circ}$ (for $etasim -3.0$) or $|b_{
m gal}| le 20^{circ}$ (for $etasim -2.8$) from the surveys is sufficient to render the foreground contamination negligible, thus confirming the ability of WMAP to have a clear view of the temperature-polarization correlation peak and antipeak series.