J/ApJ/944/177ivo://CDS.VizieR/J/ApJ/944/177doi:10.26093/cds/vizier.19440177CDSKomossa S.Kraus A.Grupe D.Gonzalez A.G.Gurwell M.A.Gallo L.C.,Liu F.K.Myserlis I.Krichbaum T.P.Laine S.Bach U.Gomez J.L.,Parker M.L.Yao S.Berton M.2025-05-21T20:14:46Z2025-02-28T13:02:10ZCDS support team

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

cds-question@unistra.frbl-lacertae-objectsradio-sourcesmillimeter-astronomysubmillimeter-astronomyBased on our dedicated Swift monitoring program, MOMO, OJ 287 is one of the best-monitored blazars in the X-ray-UV-optical regime. Here, we report results from our accompanying, dense, multifrequency (1.4-44GHz) radio monitoring of OJ 287 between 2015 and 2022 covering a broad range of activity states. Fermi {gamma}-ray observations were added. We characterize the radio flux and spectral variability in detail, including discrete correlation function and other variability analyses, and discuss its connection with the multiwavelength emission. Deep fades of the radio and optical-UV fluxes are found to occur every 1-2 yr. Further, it is shown that a precursor flare of thermal bremsstrahlung predicted by one of the binary supermassive black hole (SMBH) models of OJ 287 was absent. We then focus on the nature of the extraordinary, nonthermal, 2016/2017 outburst that we initially discovered with Swift. We interpret it as the latest of the famous optical double-peaked outbursts of OJ 287, favoring binary scenarios that do not require a highly precessing secondary SMBH.2023ApJ...944..177Khttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/944/177CatalogResearchIsServedByTAP VizieR generic servicerelated-toIX/67 : Incremental Fermi LAT 4th source cat. (4FGL-DR3) (Fermi-LAT col., 2022)J/ApJ/700/597 : FERMI LAT detected blazars (Abdo+, 2009)J/ApJ/716/30 : SED of Fermi bright blazars (Abdo+, 2010)J/ApJ/764/5 : BR phot. of 2012 precursor flare in OJ287 (Pihajoki+, 2013)J/A+A/596/A45 : Radio light curves of 8 AGN (Fuhrmann+, 2016)J/AJ/151/54 : VRIJHK photometry of 3C 279 (Sandrinelli+, 2016)J/A+A/597/A80 : GMVA 86GHz images of OJ 287 (Hodgson+, 2017)J/A+A/619/A88 : High cadence polarization monitoring of OJ287 (Myserlis+, 2018)J/ApJ/902/104 : Korean VLBI Network monitoring of OJ 287 (Lee+, 2020)J/ApJ/923/30 : MOJAVE. XVIII. Bright radio-loud active AGNs (Lister+, 2021)J/ApJS/260/12 : Jet kinematics of blazars at 43GHz (Weaver+, 2022)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/944/177https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/944/177http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/944/177https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/944/177https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/944/177http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/944/177GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapMillimeterRadiodefaultJ/ApJ/944/177/table6Radio flux density measurements of OJ 287 between 1.4 and 44GHz obtained at the Effelsberg telescope in the course of the MOMO project between 2017 January and 2022 JunerecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintnu[1.4/43.75] Radio frequencyGHzem.freqfloatMJD[57757.15/59752.63] Modified Julian date (JD-2400000.5)dtime.epochdoubleSnu[2/11.2] Flux densityJyphot.flux.density;em.radiofloate_Snu[0.003/1.4] Uncertainty in SnuJystat.error;phot.flux.density;em.radiofloatJ/ApJ/944/177/table7Radio flux density measurements of OJ 287 from the SMA between 2015 October and 2022 JunerecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintMJD[57309.63/59760.21] Modified Julian date (JD-2400000.5)dtime.epochdoubleBandSMA radio band ("1.3 mm", "870 um" or "1.1 mm")instr.bandpasscharnu[212.97/351.36] Radio frequencyGHzem.freqfloatSnu[1.4/6.3] Flux density at nuJyphot.flux.density;em.mmfloate_Snu[0.07/0.5] Uncertainty in SnuJystat.error;phot.flux.density;em.mmfloat