Non-Gaussianity due to possible residual foreground signals in Wilkinson Microwave Anistropy Probe first-year data using spherical wavelet approaches | |
Liu, X ; Zhang, SN | |
2010-05-06 ; 2010-05-06 | |
关键词 | cosmic microwave background methods : data analysis DETECT NON-GAUSSIANITY BACKGROUND-RADIATION WMAP OBSERVATIONS INFLATIONARY UNIVERSE CROSS-CORRELATION MAPS FLUCTUATIONS STATISTICS EMISSION SKY Astronomy & Astrophysics |
中文摘要 | We perform multiscale non-Gaussianity detection and localization to the Wilkinson Microwave Anisotropy Probe (WMAP) first-year data in both wavelet and real spaces. Such an analysis is facilitated by spherical wavelet transform and inverse transform techniques developed by the YAWtb team. Skewness and kurtosis as test statistics are calculated on scales from about 1 degrees to 30 degrees on the sky, as well as toward different directions using anisotropic spherical Morlet wavelets (SMW). A maximum deviation from Gaussian simulations with a right tail probability of similar to 99.9% is detected at an angular scale of similar to 12 degrees at an azimuthal orientation of similar to 0 degrees on the sky. In addition, some significant non-Gaussian spots have been identified and localized in real space from both the combined Q-V-W map recommended by the WMAP team and the Tegmark foreground-cleaned map. Systematic effects due to beams and noise can be rejected as the source of this non-Gaussianity. Several tests show that residual foreground contamination may significantly contribute to this non-Gaussian feature. It is thus still premature to do more precise tests on the non-Gaussianity of the intrinsic CMB fluctuations before we can identify the origin of these foreground signals, understand their nature, and finally remove them from the CMB maps completely. |
语种 | 英语 ; 英语 |
出版者 | UNIV CHICAGO PRESS ; CHICAGO ; 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA |
内容类型 | 期刊论文 |
源URL | [http://hdl.handle.net/123456789/15175] |
专题 | 清华大学 |
推荐引用方式 GB/T 7714 | Liu, X,Zhang, SN. Non-Gaussianity due to possible residual foreground signals in Wilkinson Microwave Anistropy Probe first-year data using spherical wavelet approaches[J],2010, 2010. |
APA | Liu, X,&Zhang, SN.(2010).Non-Gaussianity due to possible residual foreground signals in Wilkinson Microwave Anistropy Probe first-year data using spherical wavelet approaches.. |
MLA | Liu, X,et al."Non-Gaussianity due to possible residual foreground signals in Wilkinson Microwave Anistropy Probe first-year data using spherical wavelet approaches".(2010). |
个性服务 |
查看访问统计 |
相关权益政策 |
暂无数据 |
收藏/分享 |
除非特别说明,本系统中所有内容都受版权保护,并保留所有权利。
修改评论