J/ApJ/825/59ivo://CDS.VizieR/J/ApJ/825/59doi:10.26093/cds/vizier.18250059CDSAnderson C.S.Gaensler B.M.Feain I.J.2018-02-02T10:34:12Z2016-10-10T13:45:39ZCDS support team

CDS, Observatoire de Strasbourg, 11 rue de l'Universite, F-67000 Strasbourg, France

cds-question@unistra.frradio-sourcespolarimetrymagellanic-cloudsWe present a broadband polarization analysis of 36 discrete polarized radio sources over a very broad, densely sampled frequency band. Our sample was selected on the basis of polarization behavior apparent in narrowband archival data at 1.4GHz: half the sample shows complicated frequency-dependent polarization behavior (i.e., Faraday complexity) at these frequencies, while half shows comparatively simple behavior (i.e., they appear Faraday simple). We re-observed the sample using the Australia Telescope Compact Array in full polarization, with 6GHz of densely sampled frequency coverage spanning 1.3-10GHz. We have devised a general polarization modeling technique that allows us to identify multiple polarized emission components in a source, and to characterize their properties. We detect Faraday complex behavior in almost every source in our sample. Several sources exhibit particularly remarkable polarization behavior. By comparing our new and archival data, we have identified temporal variability in the broadband integrated polarization spectra of some sources. In a number of cases, the characteristics of the polarized emission components, including the range of Faraday depths over which they emit, their temporal variability, spectral index, and the linear extent of the source, allow us to argue that the spectropolarimetric data encode information about the magneto-ionic environment of active galactic nuclei themselves. Furthermore, the data place direct constraints on the geometry and magneto-ionic structure of this material. We discuss the consequences of restricted frequency bands on the detection and interpretation of polarization structures, and the implications for upcoming spectropolarimetric surveys.2016ApJ...825...59Ahttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/825/59CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toJ/AJ/149/60 : Modeling Faraday structures. I. 1100-1400 MHz (Sun+, 2015)J/MNRAS/436/2915 : Polarization of bright AT20G sources (Massardi+, 2013)J/MNRAS/434/956 : AT20G high-angular-resolution catalogue (Chhetri+, 2013)J/AJ/144/105 : MOJAVE. VIII. Faraday rotation in AGN jets. (Hovatta+, 2012)J/ApJ/759/25 : Rotation measures at 1.4GHz toward the LMC (Mao+, 2012)J/MNRAS/402/2403 : Australia Telescope 20GHz Survey (AT20G) (Murphy+, 2010)J/ApJ/707/114 : Faraday rotation in Cen A (Feain, 2009)J/ApJS/45/97 : Extragal. Radio Sources Faraday Rot. (Simard-Normandin+ 1981)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/825/59https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/825/59http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/825/59https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/825/59https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/825/59http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/825/59GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJ/825/59/table2 (Selected observational properties of our sample sources)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/825/59/table2?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/825/59/table2?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/825/59/table2?GETtext/xml+votable180.050000true68.9247917-62.97896390.0055555555555555566/33043 33048 33059 33102 33128 33132 33232 33794 33824 37408 37512 37513 43230 43250 43251 43252 43255 43257 43400 43432 43435 43606 43612 43614 43637 43776 43779 43780 43786https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJ/825/59?format=asciiRadiodefaultJ/ApJ/825/59/table2Selected observational properties of our sample sourcesrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintIDSource identifiermeta.id;meta.maincharprimaryRAJ2000[4/13] Hour of Right Ascension (J2000)pos.eq.ra;meta.mainDEJ2000[38/74] Degree of Declination (J2000)pos.eq.dec;meta.mainBandSelf calibrated band(s)cminstr.bandpasscharSize[2/90]? Maximum angular size (1)arcsecphys.angSize;stat.maxintnullableResResolved over 1.3-10GHz (2)pos.angResolutioncharI1.4[0.007/2.2] Stokes I model value at 1.4GHzJyphys.polarization.stokesfloate_I1.4[0.0002/0.004] Uncertainty in I1.4Jystat.errorfloatImod[1/7] Polynomial degree of I1.4stat.fit.paramintSpInd[-2.3/0.4] Mean spectral index over the 1.3-10GHz bandspect.index;em.radio.3-6GHz;stat.meanfloate_SpInd[0.002/0.2] Uncertainty in SpIndstat.errorfloatVisAT20G High angular resolution catalog visibility ratio(s) (3)phot.flux;arith.ratiocharFig? Figure number for this resolved source; column added by CDS (4)meta.idintnullableAT20GDisplay data from the AT20G high-angular-resolution catalog (Chhetri+, 2013, J/MNRAS/434/956) within 15"meta.ref.urlcharJ/ApJ/825/59/table6The spectropolarimetric datarecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintIDSource identifiermeta.id;meta.maincharprimarynu[1.27/9.91] FrequencyGHzem.freqdoubleI[-0.0017/2.2] Stokes I dataJyphot.flux.density;em.opt.Idoublee_I[0.00015/0.015] Uncertainty in IJystat.errordoubleQ[-0.035/0.043] Stokes Q dataJyphot.flux.density;em.IR.15-30umdoublee_Q[0/0.007] Uncertainty in QJystat.errordoubleU[-0.042/0.025] Stokes U dataJyphot.flux.density;em.opt.Udoublee_U[0.0001/0.004] Uncertainty in UJystat.error;pos.cartesian.xdoubleV[-0.02/0.02] Stokes V dataJyphot.flux.density;em.opt.Vdoublee_V[0.0001/0.005] Uncertainty in VJystat.error;pos.cartesian.ydouble