English   español  
Please use this identifier to cite or link to this item: http://hdl.handle.net/10261/109294
Share/Impact:
Statistics
logo share SHARE logo core CORE   Add this article to your Mendeley library MendeleyBASE

Visualizar otros formatos: MARC | Dublin Core | RDF | ORE | MODS | METS | DIDL
Exportar a otros formatos:
Title

A polarization survey of bright extragalactic AT20G sources

AuthorsMassardi, Marcella; López-Caniego, M. ; Negrello, Mattia; Zotti, G. de; Partridge, B.; Sadler, E. M.
KeywordsRadio continuum: galaxies
Techniques: polarimetric
Galaxies: active
Surveys
Polarization
Issue Date2013
PublisherOxford University Press
Royal Astronomical Society
CitationMonthly Notices of the Royal Astronomical Society 436(4): 2915-2928 (2013)
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 ~ 1mJy). 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 declinationδ < -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. © 2013 The Authors Published by Oxford University Press on behalf of the Royal Astronomical Society.
Descriptionet al.
Publisher version (URL)http://dx.doi.org/10.1093/mnras/stt1717
URIhttp://hdl.handle.net/10261/109294
DOI10.1093/mnras/stt1717
Identifiersdoi: 10.1093/mnras/stt1717
issn: 0035-8711
e-issn: 1365-2966
Appears in Collections:(IFCA) Artículos
Files in This Item:
File Description SizeFormat 
AT20G sources.pdf401,14 kBAdobe PDFThumbnail
View/Open
Show full item record
Review this work
 

Related articles:


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