Alignment and signed-intensity anomalies in Wilkinson Microwave Anisotropy Probe data

Significant alignment and signed‐intensity anomalies of local features of the cosmic microwave background (CMB) are detected on the three‐year Wilkinson Microwave Anisotropy Probe data, through a decomposition of the signal with steerable wavelets on the sphere. In addition to identifying local feat...

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Detalles Bibliográficos
Autores: Vielva, Patricio, Wiaux, Y., Martínez-González, Enrique, Vandergheynst, P.
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2007
País:España
Institución:Consejo Superior de Investigaciones Científicas (CSIC)
Repositorio:DIGITAL.CSIC. Repositorio Institucional del CSIC
OAI Identifier:oai:digital.csic.es:10261/384569
Acceso en línea:http://hdl.handle.net/10261/384569
Access Level:acceso abierto
Palabra clave:Methods: data analysis
Techniques: image processing
Cosmic microwave background
Cosmology: observations
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spelling Alignment and signed-intensity anomalies in Wilkinson Microwave Anisotropy Probe dataVielva, PatricioWiaux, Y.Martínez-González, EnriqueVandergheynst, P.Methods: data analysisTechniques: image processingCosmic microwave backgroundCosmology: observationsSignificant alignment and signed‐intensity anomalies of local features of the cosmic microwave background (CMB) are detected on the three‐year Wilkinson Microwave Anisotropy Probe data, through a decomposition of the signal with steerable wavelets on the sphere. In addition to identifying local features of a signal at specific scales, steerable wavelets allow one to determine their local orientation and signed intensity. First, an alignment analysis identifies two mean preferred planes in the sky, both with normal axes close to the CMB dipole axis. The first plane is defined by the directions towards which local CMB features are anomalously aligned. A mean preferred axis is also identified in this plane, located very close to the ecliptic poles axis. The second plane is defined by the directions anomalously avoided by local CMB features. This alignment anomaly provides further insight on recent results. Secondly, a signed‐intensity analysis identifies three mean preferred directions in the southern Galactic hemisphere with anomalously high or low temperature of local CMB features: a cold spot essentially identified with a known cold spot, a second cold spot lying very close to the southern end of the CMB dipole axis, and a hotspot lying close to the southern end of the ecliptic poles axis. In both analyses, the anomalies are observed at wavelet scales corresponding to angular sizes around 10° on the celestial sphere, with global significance levels around 1 per cent. Further investigation reveals that the alignment and signed‐intensity anomalies are only very partially related. Instrumental noise, foreground emissions and some form of other systematics are strongly rejected as possible origins of the detections. An explanation might still be envisaged in terms of a global violation of the isotropy of the Universe, inducing an intrinsic statistical anisotropy of the CMB.The work of PV is funded through an I3P contract from the Spanish National Research Council (CSIC). PV and EM‐G are also supported by the Spanish MCYT project ESP2004‐07067‐C03‐01. The work of YW is funded by the Swiss National Science Foundation (SNF) under contract no. 200021‐107478/1. YW is also postdoctoral researcher of the Belgian National Science Foundation (FNRS).Peer reviewedOxford University PressConsejo Superior de Investigaciones Científicas (España)Ministerio de Ciencia y Tecnología (España)Swiss National Science FoundationNational Fund for Scientific Research (Belgium)Consejo Superior de Investigaciones Científicas [https://ror.org/02gfc7t72]202520252007info:eu-repo/semantics/articlehttp://purl.org/coar/resource_type/c_6501Publisher's versioninfo:eu-repo/semantics/publishedVersionapplication/pdfhttp://hdl.handle.net/10261/384569reponame:DIGITAL.CSIC. Repositorio Institucional del CSICinstname:Consejo Superior de Investigaciones Científicas (CSIC)Ingléshttps://doi.org/10.1111/j.1365-2966.2007.12290.xSíinfo:eu-repo/semantics/openAccessoai:digital.csic.es:10261/3845692026-05-22T06:33:51Z
dc.title.none.fl_str_mv Alignment and signed-intensity anomalies in Wilkinson Microwave Anisotropy Probe data
title Alignment and signed-intensity anomalies in Wilkinson Microwave Anisotropy Probe data
spellingShingle Alignment and signed-intensity anomalies in Wilkinson Microwave Anisotropy Probe data
Vielva, Patricio
Methods: data analysis
Techniques: image processing
Cosmic microwave background
Cosmology: observations
title_short Alignment and signed-intensity anomalies in Wilkinson Microwave Anisotropy Probe data
title_full Alignment and signed-intensity anomalies in Wilkinson Microwave Anisotropy Probe data
title_fullStr Alignment and signed-intensity anomalies in Wilkinson Microwave Anisotropy Probe data
title_full_unstemmed Alignment and signed-intensity anomalies in Wilkinson Microwave Anisotropy Probe data
title_sort Alignment and signed-intensity anomalies in Wilkinson Microwave Anisotropy Probe data
dc.creator.none.fl_str_mv Vielva, Patricio
Wiaux, Y.
Martínez-González, Enrique
Vandergheynst, P.
author Vielva, Patricio
author_facet Vielva, Patricio
Wiaux, Y.
Martínez-González, Enrique
Vandergheynst, P.
author_role author
author2 Wiaux, Y.
Martínez-González, Enrique
Vandergheynst, P.
author2_role author
author
author
dc.contributor.none.fl_str_mv Consejo Superior de Investigaciones Científicas (España)
Ministerio de Ciencia y Tecnología (España)
Swiss National Science Foundation
National Fund for Scientific Research (Belgium)
Consejo Superior de Investigaciones Científicas [https://ror.org/02gfc7t72]
dc.subject.none.fl_str_mv Methods: data analysis
Techniques: image processing
Cosmic microwave background
Cosmology: observations
topic Methods: data analysis
Techniques: image processing
Cosmic microwave background
Cosmology: observations
description Significant alignment and signed‐intensity anomalies of local features of the cosmic microwave background (CMB) are detected on the three‐year Wilkinson Microwave Anisotropy Probe data, through a decomposition of the signal with steerable wavelets on the sphere. In addition to identifying local features of a signal at specific scales, steerable wavelets allow one to determine their local orientation and signed intensity. First, an alignment analysis identifies two mean preferred planes in the sky, both with normal axes close to the CMB dipole axis. The first plane is defined by the directions towards which local CMB features are anomalously aligned. A mean preferred axis is also identified in this plane, located very close to the ecliptic poles axis. The second plane is defined by the directions anomalously avoided by local CMB features. This alignment anomaly provides further insight on recent results. Secondly, a signed‐intensity analysis identifies three mean preferred directions in the southern Galactic hemisphere with anomalously high or low temperature of local CMB features: a cold spot essentially identified with a known cold spot, a second cold spot lying very close to the southern end of the CMB dipole axis, and a hotspot lying close to the southern end of the ecliptic poles axis. In both analyses, the anomalies are observed at wavelet scales corresponding to angular sizes around 10° on the celestial sphere, with global significance levels around 1 per cent. Further investigation reveals that the alignment and signed‐intensity anomalies are only very partially related. Instrumental noise, foreground emissions and some form of other systematics are strongly rejected as possible origins of the detections. An explanation might still be envisaged in terms of a global violation of the isotropy of the Universe, inducing an intrinsic statistical anisotropy of the CMB.
publishDate 2007
dc.date.none.fl_str_mv 2007
2025
2025
dc.type.none.fl_str_mv info:eu-repo/semantics/article
http://purl.org/coar/resource_type/c_6501
Publisher's version
info:eu-repo/semantics/publishedVersion
format article
status_str publishedVersion
dc.identifier.none.fl_str_mv http://hdl.handle.net/10261/384569
url http://hdl.handle.net/10261/384569
dc.language.none.fl_str_mv Inglés
language_invalid_str_mv Inglés
dc.relation.none.fl_str_mv https://doi.org/10.1111/j.1365-2966.2007.12290.x
Sí
dc.rights.none.fl_str_mv info:eu-repo/semantics/openAccess
eu_rights_str_mv openAccess
dc.format.none.fl_str_mv application/pdf
dc.publisher.none.fl_str_mv Oxford University Press
publisher.none.fl_str_mv Oxford University Press
dc.source.none.fl_str_mv reponame:DIGITAL.CSIC. Repositorio Institucional del CSIC
instname:Consejo Superior de Investigaciones Científicas (CSIC)
instname_str Consejo Superior de Investigaciones Científicas (CSIC)
reponame_str DIGITAL.CSIC. Repositorio Institucional del CSIC
collection DIGITAL.CSIC. Repositorio Institucional del CSIC
repository.name.fl_str_mv
repository.mail.fl_str_mv
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