J/ApJ/862/1ivo://CDS.VizieR/J/ApJ/862/1doi:10.26093/cds/vizier.18620001CDSCohen M.H.Aller H.D.Aller M.F.Hovatta T.Kharb P.Kovalev Y.Y.,Lister M.L.Meier D.L.Pushkarev A.B.Savolainen T.2019-11-27T11:28:09Z2019-08-14T13:44:12ZCDS support team

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

cds-question@unistra.frpolarimetrybl-lacertae-objectsradio-continuum-emissionWe have obtained a smooth time series for the electric vector position angle (EVPA) of the blazar OJ 287 at centimeter wavelengths, by making +/-n{pi} adjustments to archival values from 1974 to 2016. The data display rotation reversals in which the EVPA rotates counterclockwise for ~180{deg} and then rotates clockwise by a similar amount. The timescale of the rotations is a few weeks to a year, and the scale for a double rotation, including the reversal, is 1-3yr. We have seen four of these events in 40yr. A model consisting of two successive outbursts in polarized flux density, with EVPAs counterrotating, superposed on a steady polarized jet, can explain many of the details of the observations. Polarization images support this interpretation. The model can also help to explain similar events seen at optical wavelengths. The outbursts needed for the model can be generated by the supermagnetosonic jet model of Nakamura+ (2010ApJ...721.1783N) and Nakamura & Meier (2014ApJ...785..152N), which requires a strong helical magnetic field. This model produces forward and reverse pairs of fast and slow MHD waves, and the plasma inside the two fast/slow pairs rotates around the jet axis, but in opposite directions.2018ApJ...862....1Chttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/862/1CatalogResearchIsServedByTAP VizieR generic servicerelated-toJ/A+AS/39/379 : Linear Polarization of radio sources (Tabara+ 1980)J/AJ/87/859 : Polarisation of 404 radio sources at 6 and 20cm (Perley, 1982)J/A+AS/129/569 : BVRI photometry of OJ 287 (Jia Guibin+ 1998)J/A+AS/139/545 : 1-22 GHz spectra survey (Kovalev+, 1999)J/ApJ/522/846 : Optical monitoring of GeV loud blazars (Xie+, 1999)J/A+A/441/915 : Alignments of quasar polarization vectors (Hutsemekers+, 2005)J/AJ/130/1418 : AGN jet kinematics (Jorstad+, 2005)J/AJ/130/1389 : Linear polarization of AGN jets at 15GHz (Lister+, 2005)J/AJ/131/1262 : Circ. polarization images at 15GHz of AGN jets (Homan+, 2006)J/AJ/132/1256 : eim BATC photometry of OJ 287 (Wu+, 2006)J/AJ/133/1947 : 37GHz observations of BL Lac objects (Nieppola+, 2007)J/AJ/134/799 : Multiwaveband polarimetry of 15 AGN (Jorstad+, 2007)J/MNRAS/380/162 : Aligned radio polarizations of quasars (Joshi+, 2007)J/MNRAS/385/823 : UBVRI light curves of OJ 287 (Zheng+, 2008)J/AJ/137/3718 : 15GHz monitoring of AGN jets with VLBA (Lister+, 2009)J/MNRAS/402/2087 : Opt. polarization of OJ 287 in 2005-2009 (Villforth+, 2010)J/ApJS/189/1 : A 3.5mm polarimetric survey of radio-loud AGNs (Agudo+, 2010)J/ApJS/194/19 : Optical linear polarization at McDonald Obs. (Wills+, 2011)J/AJ/141/65 : BATC ceimo light curves of OJ 287 (Dai+, 2011)J/MNRAS/421/1861 : OJ287 polarization and VLBI jet direction (Valtonen+, 2012)J/ApJ/747/63 : 7mm VLBA observations of BL Lac object OJ287 (Agudo+, 2012)J/ApJ/764/5 : BR photom. of 2012 precursor flare in OJ287 (Pihajoki+, 2013)J/AJ/146/120 : MOJAVE. X. Parsec-scale kinematics of AGNs (Lister+, 2013)J/A+A/559/A20 : Historical outbursts of OJ287 (Hudec+, 2013)J/ApJ/787/151 : Fitted jet components in BL Lacertae (Cohen+, 2014)J/MNRAS/442/1693 : Gamma-ray-loud blazars opt. polarization (Pavlidou+, 2014)J/A+A/566/A59 : 3.5 & 1.3mm pol. survey of Northern AGNs (Agudo+, 2014)J/ApJS/212/15 : Polarized NVSS sources SEDs (Farnes+, 2014)J/A+A/596/A45 : Radio light curves of 8 AGN (Fuhrmann+, 2016)J/A+A/590/A10 : 3C 279 optical photometry and polarimetry (Kiehlmann+, 2016)J/AJ/152/12 : MOJAVE. XIII. New 15GHz obs. on 1994-2013 (Lister+, 2016)J/ApJ/833/77 : gamma-ray bright blazars optical polarization (Itoh+, 2016)J/ApJ/835/275 : OJ287 flux+polarization during 2016 outburst (Rakshit+, 2017)J/ApJ/846/98 : Jet kinematics of blazars at 43GHz with VLBA (Jorstad+, 2017)J/A+A/597/A80 : GMVA 86GHz images of OJ 287 (Hodgson+, 2017)J/ApJS/234/12 : MOJAVE XV. VLBA 15GHz obs. of AGN jets (Lister+, 2018)J/A+A/609/A68 : Full-Stokes polarimetry of 5 radio sources (Myserlis+, 2018)J/A+A/610/A74 : OJ 287 far-infrared photometry (Kidger+, 2018)J/A+A/619/A88 : OJ287 high cadence polarization monitoring (Myserlis+, 2018)J/AJ/157/95 : Optical variability of OJ 287 in 2016-2017 (Gupta+, 2019)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/862/1https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/862/1http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/862/1https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/862/1https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/862/1http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/862/1GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tap6.62606957030801e-24 6.62606957030801e-24RadiodefaultJ/ApJ/862/1/table1University of Michigan Radio Astronomy Observatory (UMRAO) single dish datarecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintDate[1971.3/2012.5] Observation epoch, fractional yearyrtime.epoch;obsdoublenu[4.8/14.5] Observation frequencyGHzem.freq;obsfloatFtot[1/10.4] Total flux densityJyphot.flux.density;em.radiofloatPol[0.4/17.5] Fractional linear polarization%phys.polarization.linearfloatEVPA[-1000/202.5] Adjusted electric vector position angledegpos.posAng;phys.polarizationfloatJ/ApJ/862/1/table2MOJAVE 15GHz VLBA core feature datarecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintDate[1996/2015.6] Observation epoch, fractional yearyrtime.epoch;obsdoubleI[0.86/5.96] Stokes I intensityJy/beamphys.polarization.stokesfloatPol[0.2/10.8] Fractional linear polarization%phys.polarization.linearfloatEVPA[-90/198] Adjusted electric vector position angledegpos.posAng;phys.polarizationintJ/ApJ/862/1/table3Kikuchi+ (1988A&A...190L...8K) 10GHz radio datarecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintDate[1986/1986.5] Observation Epoch, fractional yearyrtime.epoch;obsdoubleFtot[0.2/2.7]? Total flux density at 10GHzJyphot.flux.density;em.radio.6-12GHzfloatnullablePol[3.5/7.2]? Fractional linear polarization%phys.polarization.linearfloatnullableEVPA[-206/108]? Adjusted electric vector position angledegpos.posAng;phys.polarizationfloatnullable