J/MNRAS/523/3615ivo://CDS.VizieR/J/MNRAS/523/3615doi:10.26093/cds/vizier.75233615CDSZobnina D.I.Aller H.D.Aller M.F.Homan D.C.Kovalev Y.Y.,Lister M.L.Pashchenko I.N.Pushkarev A.B.Savolainen T.2024-08-22T20:17:25Z2023-07-19T06:18:57ZCDS support team

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

cds-question@unistra.frradio-galaxiesactive-galactic-nucleiinterferometryvery-long-baseline-interferometryUsing stacking of images obtained at different epochs, we studied the variability properties of linear polarization of active galactic nucleus (AGN) jets on parsec-scales. Our sample is drawn from the MOJAVE programme, and consists of 436 AGNs manifesting core-jet morphology and having at least five VLBA observing epochs at 15 GHz from 1996 January through 2019 August, with some additional archival VLBA data reduced by us. We employed a stacking procedure and constructed maps of (i) standard deviation of fractional polarization and electric vector position angle (EVPA) over epochs as the measure of variability and (ii) median polarization degree to quantify typical values in time. The distributions of these values along and across the jet were analysed for the whole sample for the first time. We found that core EVPA variability is typically higher than that of the jet, presumably due to component blending and outflow bends in the core. The BL Lacertae object cores have lower EVPA variability, compared to that of quasars, possibly due to lower Faraday rotation measure, suggesting a stronger ordered magnetic field component. The EVPA becomes more stable down the jet. Most of the sources showing this trend have a time coverage of more than 12 yr and at least 15 epochs. The possible cause could be the increase of stability in the magnetic field direction, reflecting an increase in the fraction of the magnetic field that is ordered. There are no significant optical-class-dependent or spectral-class-dependent relations in the EVPA variability properties in AGN jets.2023MNRAS.523.3615Zhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/MNRAS/523/3615CatalogResearchIsServedByTAP VizieR generic servicerelated-toJ/AJ/137/3718 : 15GHz monitoring of AGN jets with VLBA (Lister+, 2009)J/ApJS/171/376 : MOJAVE. III. VLA 1.4GHz images (Cooper+, 2007)J/AJ/131/1262 : Circular polarization images at 15GHz of AGN jetsJ/AJ/130/1389 : Linear polarization of AGN jets at 15GHz (Lister+, 2005)J/AJ/138/1874 : MOJAVE. VI. Kinematic analysis of blazar jetsJ/ApJ/706/1253 : MOJAVE VII. Blazar jet acceleration (Homan+, 2009)J/AJ/144/105 : MOJAVE. VIII. Faraday rotation in AGN jets. (Hovatta+, 2012)J/A+A/545/A113 : MOJAVE IX. Core shift effects (Pushkarev+, 2012)J/AJ/146/120 : MOJAVE. X. Parsec-scale kinematics of AGNs (Lister+, 2013)J/AJ/147/143 : MOJAVE. XI. Spectral distributions (Hovatta+, 2014)J/ApJ/798/134 : MOJAVE. XII. Acceleration of blazar jets (Homan+, 2015)J/AJ/152/12 : MOJAVE. XIII. New 15GHz observations on 1994-2013J/MNRAS/468/4992 : MOJAVE XIV. AGN jet shapes + opening anglesJ/ApJS/234/12 : MOJAVE XV. VLBA 15GHz obs. of AGN jets 1996-2016J/ApJ/862/151 : MOJAVE. XVI: parsec-scale AGN jet cores at 15GHzJ/ApJ/874/43 : MOJAVE. XVII. Parsec-scale jet kinematics of AGNsJ/MNRAS/520/6053 : MOJAVE. XX. Persistent polarization in AGN jetshttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/MNRAS/523/3615https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/MNRAS/523/3615http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/MNRAS/523/3615https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/MNRAS/523/3615https://vizier.iucaa.in/viz-bin/votable?-source=J/MNRAS/523/3615http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/MNRAS/523/3615GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapRadiodefaultJ/MNRAS/523/3615/table2Source general characteristicsrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNameB1950Source name (HHMM+DDd, B1950)meta.id;meta.maincharONameOther namemeta.idcharOptClassOptical classsrc.classcharSEDClassSED peak classsrc.classcharz? Redshiftsrc.redshiftfloatnullableRefReference for redshift / optical classmeta.ref;pos.framecharSimbadNameSimbad column added by the CDSmeta.idcharnullableJ/MNRAS/523/3615/table4Observational and multi-epoch source propertiesrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNameB1950Source name (HHMM+DDd, B1950)meta.id;meta.maincharEpochDate of first epochtime.epochnullabletauTime range between first and last epochsyrtime.intervalfloatNNumber of stacked epochsmeta.numberintbFWHM of circular restoring beammasphys.angSize.smajAxisfloatImean-peakMap peak in mean total intensitymJy/beamphot.flux.density;em.radio.12-30GHzdoubleImean-rmsNoise level of mean total intensity mapmJy/beaminstr.det.noise;stat.meanfloatPmed-peak? Map peak in median linearly polarized intensitymJy/beamphot.flux.density;em.radio.12-30GHzfloatnullablePmed-rms? Median epoch noise level of linearly polarized intensitymJy/beaminstr.det.noise;stat.medianfloatnullable