Foreground influence on primordial non-Gaussianity estimates: needlet analysis of WMAP 5-year data

被引:15
作者
Cabella, P. [1 ]
Pietrobon, D. [1 ,2 ]
Veneziani, M. [4 ]
Balbi, A. [1 ,3 ]
Crittenden, R. [2 ]
de Gasperis, G. [1 ]
Quercellini, C. [1 ]
Vittorio, N. [1 ,3 ]
机构
[1] Univ Roma Tor Vergata, Dipartimento Fis, I-00173 Rome, Italy
[2] Inst Cosmol & Gravitat, Portsmouth PO1 3FX, Hants, England
[3] INFN Sez Roma Tor Vergata, I-00133 Rome, Italy
[4] Univ Roma La Sapienza, Dipartimento Fis, I-00185 Rome, Italy
关键词
methods: data analysis; cosmic background radiation; early Universe; MICROWAVE BACKGROUND MAPS; ANISOTROPY-PROBE DATA; COMPONENT SEPARATION; PARAMETER F(NL); INFLATIONARY UNIVERSE; SPHERICAL NEEDLETS; DARK ENERGY; CONSTRAINTS; WAVELETS; BISPECTRUM;
D O I
10.1111/j.1365-2966.2010.16542.x
中图分类号
P1 [天文学];
学科分类号
0704 ;
摘要
We constrain the amplitude of primordial non-Gaussianity in the cosmic microwave background data taking into account the presence of foreground residuals in the maps. We generalize the needlet bispectrum estimator marginalizing over the amplitudes of thermal dust, free-free and synchrotron templates. We apply our procedure to Wilkinson Microwave Anisotropy Probe 5-year data, finding f(NL) = 38 +/- 47 (1 Sigma), while the analysis without marginalization provides f(NL) = 35 +/- 42. Splitting the marginalization over each foreground separately, we found that the estimates of f(NL) are positively cross-correlated of 17 and 12 per cent with the dust and synchrotron, respectively, while a negative cross-correlation of about -10 per cent is found for the free-free component.
引用
收藏
页码:961 / 968
页数:8
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