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dc.contributor.authorMassardi, Marcella
dc.contributor.authorBurke-Spolaor, S. G.
dc.contributor.authorMurphy, T.
dc.contributor.authorRicci, R.
dc.contributor.authorLópez-Caniego Alcarria, Marcos
dc.contributor.authorNegrello, Mattia
dc.contributor.authorChhetri, R.
dc.contributor.authorDe Zotti, Gianfranco
dc.contributor.authorEkers, R. D.
dc.contributor.authorPartridge, R. B.
dc.contributor.authorSadler, E. M.
dc.contributor.otherUniversidad de Cantabriaes_ES
dc.date.accessioned2014-04-08T11:02:40Z
dc.date.available2014-06-30T03:00:05Z
dc.date.issued2013-12
dc.identifier.issn0035-8711
dc.identifier.issn1365-2966
dc.identifier.urihttp://hdl.handle.net/10902/4532
dc.description.abstractWe present polarization data for 180 extragalactic sources extracted from the Australia Telescope 20 GHz (AT20G) survey catalogue and observed with the Australia Telescope Compact Array during a dedicated, high sensitivity run (σP ∼ 1 mJy). For the sake of completeness, we extracted the polarization information for seven extended sources from the 9 yr Wilkinson Microwave Anisotropy Probe co-added maps at 23 GHz. The full sample of 187 sources constitutes a ≃99 per cent complete sample of extragalactic sources brighter than S20GHz = 500 mJy at the selection epoch with declination δ < −30°. The sample has a 91.4 per cent detection rate in polarization at ∼20 GHz (94 per cent if considering the subsample of point-like sources). We have measurements also at 4.8 and 8.6 GHz within ∼1 month of the 20 GHz observations for 172 sources to reconstruct the spectral properties of the sample in total intensity and in polarization: 143 of them have a polarization detection at all three frequencies. We find that there is no statistically significant evidence of a relationship either between the fraction of polarization and frequency or between the fraction of polarization and the total intensity flux density. This indicates that Faraday depolarization is not very important above 4.8 GHz and that the magnetic field is not substantially more ordered in the regions dominating the emission at higher frequencies (up to 20 GHz). We estimate the distribution of the polarization fraction and the polarized flux density source counts at ∼20 GHz.es_ES
dc.format.extent14 p.es_ES
dc.language.isoenges_ES
dc.publisherOxford University Presses_ES
dc.publisherRoyal Astronomical Societyes_ES
dc.rights© 2013 The Authors Published by Oxford University Press on behalf of the Royal Astronomical Societyes_ES
dc.sourceMonthly Notices of the Royal Astronomical Society, vol. 436, iss.4, Pp.2915-2928 (2013)es_ES
dc.subject.otherPolarizationes_ES
dc.subject.otherTechniques: polarimetrices_ES
dc.subject.otherSurveyses_ES
dc.subject.otherGalaxies: activees_ES
dc.subject.otherRadio continuum: galaxieses_ES
dc.titleA polarization survey of bright extragalactic AT20G sourceses_ES
dc.typeinfo:eu-repo/semantics/articlees_ES
dc.relation.publisherVersionhttp://dx.doi.org/10.1093/mnras/stt1717es_ES
dc.rights.accessRightsopenAccesses_ES
dc.identifier.DOI10.1093/mnras/stt1717
dc.type.versionpublishedVersiones_ES
dc.date.embargoEndDate2014-06-30


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