English   español  
Please use this identifier to cite or link to this item: http://hdl.handle.net/10261/10639
logo share SHARE   Add this article to your Mendeley library MendeleyBASE
Visualizar otros formatos: MARC | Dublin Core | RDF | ORE | MODS | METS | DIDL
Exportar a otros formatos:

Improved constraints on primordial non-Gaussianity for the Wilkinson Microwave Anisotropy Probe 5-yr data

AuthorsCurto, Andrés ; Martínez-González, Enrique ; Barreiro, R. Belén
KeywordsMethods: data analysis
Cosmic microwave background
Cosmology and Extragalactic Astrophysics
Issue Date9-Feb-2009
CitationarXiv:0902.1523v1 [astro-ph.CO]
AbstractWe present new constraints on the non-linear coupling parameter f(nl) with the Wilkinson Microwave Anisotropy Probe (WMAP) data. We use a method based on the spherical Mexican hat wavelet (SMHW) which provides improved constraints on the f(nl) parameter. This paper is a continuation of a previous work by Curto et al. where several third order statistics based on the SMHW were considered. In this paper, we use all the possible third order statistics computed from the wavelet coefficient maps evaluated at 12 angular scales. The scales are logarithmically distributed from 6.9 arcmin to 500 arcmin. Our analysis indicates that fnl is constrained to -18 < f(nl) < +80 at 95% confidence level (CL) for the combined V+W WMAP map. This value has been corrected by the presence of undetected point sources, which adds a positive contribution of Δf(nl) = 6 ± 5. Our result excludes at ~99% CL the best-fitting value f(nl)=87 reported by Yadav & Wandelt. We have also constrained f(nl) for the Q, V and W frequency bands separately, finding compatibility with zero at 95 % CL for the Q and V bands but not for the W band. We have performed some further tests to understand the cause of this deviation which indicate that systematics associated to the W radiometers could be responsible for this result. Finally we have performed a Galactic North-South analysis for f(nl). We have not found any asymmetry, i.e. the best-fitting f(nl) for the northern pixels is compatible with the best-fitting f(nl) for the southern pixels.
Description5 pages, 3 figures, 4 tables.
Publisher version (URL)http://arxiv.org/abs/0902.1523
Appears in Collections:(IFCA) Artículos
Files in This Item:
File Description SizeFormat 
0902.1523v1.pdf244,51 kBAdobe PDFThumbnail
Show full item record
Review this work

WARNING: Items in Digital.CSIC are protected by copyright, with all rights reserved, unless otherwise indicated.