Non-Gaussianity in the Very Small Array CMB maps with Smooth-Goodness-of-fit tests

Simple item page
dc.creatorRubino-Martin, Jose Alberto
dc.creatorAliaga, Antonio M.
dc.creatorBarreiro, R. B.
dc.creatorBattye, Richard A.
dc.creatorCarreira, Pedro
dc.creatorCleary, Kieran
dc.creatorDavies, Rod D.
dc.creatorDavis, Richard J.
dc.creatorDickinson, Clive
dc.creatorGenova-Santos, Ricardo
dc.creatorGrainge, Keith
dc.creatorGutierrez, Carlos M.
dc.creatorHafez, Yaser A.
dc.creatorHobson, Michael P.
dc.creatorJones, Michael E.
dc.creatorKneissl, Rudiger
dc.creatorLancaster, Katy
dc.creatorLasenby, Anthony
dc.creatorLeahy, J. P.
dc.creatorMaisinger, Klaus
dc.creatorMartinez-Gonzalez, Enrique
dc.creatorPooley, Guy G.
dc.creatorRajguru, Nutan
dc.creatorRebolo, Rafael
dc.creatorSanz, Jose Luis
dc.creatorSaunders, Richard D. E.
dc.creatorSavage, Richard S.
dc.creatorScaife, Anna
dc.creatorScott, Paul
dc.creatorSlosar, Anze
dc.creatorTaylor, Angela C.
dc.creatorTitterington, David
dc.creatorWaldram, Elizabeth
dc.creatorWatson, Robert A.
dc.date2006-04-04
dc.date.accessioned2026-07-07T11:57:21Z
dc.date.available2026-07-07T11:57:21Z
dc.description(Abridged) We have used the Rayner & Best (1989) smooth tests of goodness-of-fit to study the Gaussianity of the Very Small Array (VSA) data. Out of the 41 published VSA individual pointings dedicated to cosmological observations, 37 are found to be consistent with Gaussianity, whereas four pointings show deviations from Gaussianity. In two of them, these deviations can be explained as residual systematic effects of a few visibility points which, when corrected, have a negligible impact on the angular power spectrum. The non-Gaussianity found in the other two (adjacent) pointings seems to be associated to a local deviation of the power spectrum of these fields with respect to the common power spectrum of the complete data set, at angular scales of the third acoustic peak (l = 700-900). No evidence of residual systematics is found in this case, and unsubstracted point sources are not a plausible explanation either. If those visibilities are removed, a cosmological analysis based on this new VSA power spectrum alone shows no differences in the parameter constraints with respect to our published results, except for the physical baryon density, which decreases by 10 percent. Finally, the method has been also used to analyse the VSA observations in the Corona Borealis supercluster region (Genova-Santos et al. 2005), which show a strong decrement which cannot be explained as primordial CMB. Our method finds a clear deviation (99.82%) with respect to Gaussianity in the second-order moment of the distribution, and which can not be explained as systematic effects. A detailed study shows that the non-Gaussianity is produced in scales of l~500, and that this deviation is intrinsic to the data (in the sense that can not be explained in terms of a Gaussian field with a different power spectrum).
dc.description14 pages, 7 figures. Accepted for publication in MNRAS
dc.identifierhttps://arxiv.org/abs/astro-ph/0604070
dc.identifierhttp://arxiv.org/abs/astro-ph/0604070
dc.identifierMon.Not.Roy.Astron.Soc.369:909-920,2006
dc.identifierdoi:10.1111/j.1365-2966.2006.10341.x
dc.identifier.urihttp://salesiana.dossiersoluciones.com/handle/123456789/205853
dc.subjectAstrophysics
dc.titleNon-Gaussianity in the Very Small Array CMB maps with Smooth-Goodness-of-fit tests
dc.typetext

Files

Collections

arXiv