Broadband polarisation of radio AGN

DOI

We present the results from a broadband (1 to 3GHz), spectro-polarimetry study of the integrated emission from 100 extragalactic radio sources with the ATCA, selected to be highly linearly polarized at 1.4 GHz. We use a general purpose, polarization model-fitting procedure that describes the Faraday rotation measure (RM) and intrinsic polarization structure of up to three distinct polarized emission regions or 'RM components' of a source. Overall, 37%/52%/11% of sources are best fit by one/two/three RM components. However, these fractions are dependent on the signal-to-noise ratio (S/N) in polarization (more RM components more likely at higher S/N). In general, our analysis shows that sources with high integrated degrees of polarization at 1.4GHz have low Faraday depolarization, are typically dominated by a single RM component, have a steep spectral index, and a high intrinsic degree of polarization. After classifying our sample into radiative-mode and jet-mode AGN, we find no significant difference between the Faraday rotation or Faraday depolarization properties of jet-mode and radiative-mode AGN. However, there is a statistically significant difference in the intrinsic degree of polarization between the two types, with the jet-mode sources having more intrinsically ordered magnetic field structures than the radiative-mode sources. We also find a preferred perpendicular orientation of the intrinsic magnetic field structure of jet-mode AGN with respect to the jet direction, while no clear preference is found for the radiative-mode sources.

Cone search capability for table J/MNRAS/469/4034/table2 (Basic properties of all sources in the sample)

Identifier
DOI http://doi.org/10.26093/cds/vizier.74694034
Source https://dc.g-vo.org/rr/q/lp/custom/CDS.VizieR/J/MNRAS/469/4034
Related Identifier https://cdsarc.cds.unistra.fr/viz-bin/cat/J/MNRAS/469/4034
Related Identifier http://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/MNRAS/469/4034
Metadata Access http://dc.g-vo.org/rr/q/pmh/pubreg.xml?verb=GetRecord&metadataPrefix=oai_b2find&identifier=ivo://CDS.VizieR/J/MNRAS/469/4034
Provenance
Creator O'Sullivan S.P.; Purcell C.R.; Anderson C.S.; Farnes J.S.; Sun X.H.,Gaensler B.M.
Publisher CDS
Publication Year 2017
Rights https://cds.unistra.fr/vizier-org/licences_vizier.html
OpenAccess true
Contact CDS support team <cds-question(at)unistra.fr>
Representation
Resource Type Dataset; AstroObjects
Discipline Astrophysics and Astronomy; Exoplanet Astronomy; Galactic and extragalactic Astronomy; High Energy Astrophysics; Natural Sciences; Observational Astronomy; Physics