Open AccessOn the bispectrum of COBE and WMAP
Author(s) -
Magueijo João,
Medeiros João
Publication year - 2004
Publication title -
monthly notices of the royal astronomical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.058
H-Index - 383
eISSN - 1365-2966
pISSN - 0035-8711
DOI - 10.1111/j.1365-2966.2004.07912.x
Subject(s) - bispectrum , cmb cold spot , physics , astrophysics , gaussian , cosmic microwave background , cosmology , non gaussianity , spectral density , statistical physics , astronomy , anisotropy , statistics , optics , mathematics , quantum mechanics
The COBE ‐DMR 4‐yr maps displayed a strong non‐Gaussian signal in the ‘interscale’ components of the bispectrum: their observed values did not display the scatter expected from Gaussian maps. We re‐examine this and other suggested non‐Gaussian features in the light of WMAP . We find that they all disappear. Given that it was proved that COBE ‐DMR high noise levels and documented systematics could at most dilute the observed non‐Gaussian features, we conclude that this data set must have contained non‐negligible undocumented systematic errors. It turns out that the culprit is a combination of QuadCube pixelization and data collected during the ‘eclipse season’.