AN ESTIMATE OF THE PRIMORDIAL NON-GAUSSIANITY PARAMETER fNL USING THE NEEDLET BISPECTRUM FROM WMAP

被引：57

作者：

Rudjord, Oystein ^{[1
]}

Hansen, Frode K. ^{[1
]}

Lan, Xiaohong ^{[2
]}

Liguori, Michele ^{[3
]}

Marinucci, Domenico ^{[2
]}

Matarrese, Sabino ^{[4
,5
]}

机构：

[1] Univ Oslo, Inst Theoret Astrophys, N-0315 Oslo, Norway

[2] Univ Roma Tor Vergata, Dipartimento Matemat, I-00133 Rome, Italy

[3] Univ Cambridge, Ctr Math Sci, Dept Appl Math & Theoret Phys, Cambridge CB3 0WA, England

[4] Univ Padua, Dipartimento Fis G Galilei, I-35131 Padua, Italy

[5] Ist Nazl Fis Nucl, Sez Padova, I-35131 Padua, Italy

来源：

ASTROPHYSICAL JOURNAL | 2009年 / 701卷 / 01期

关键词：

cosmic microwave background; cosmology: observations; methods: statistical; MICROWAVE-ANISOTROPY-PROBE; POLARIZATION ANISOTROPIES; COLD SPOT; PERTURBATIONS; TEMPERATURE; WAVELETS;

D O I：

10.1088/0004-637X/701/1/369

中图分类号：

P1 [天文学];

学科分类号：

0704 ;

摘要：

We use the full bispectrum of spherical needlets applied to the WMAP data of the cosmic microwave background as an estimator for the primordial non-Gaussianity parameter f(NL). We use needlet scales up to l(max) = 1000 and the KQ75 galactic cut and find f(NL) = 84 +/- 40 corrected for point-source bias. We also introduce a set of consistency tests to validate our results against the possible influence of foreground residuals or systematic errors. In particular, fluctuations in the value of f(NL) obtained from different frequency channels, different masks, and different multipoles are tested against simulated maps. All variations in f(NL) estimates are found statistically consistent with simulations.

引用

页码：369 / 376

页数：8

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