J/A+A/708/A339ivo://CDS.VizieR/J/A+A/708/A339CDSJo Y.Lee S.-S.2026-07-10T12:19:27Z2026-04-23T09:09:31ZCDS support team

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

cds-question@unistra.frquasarsradio-sourcesgamma-ray-astronomyWe present a multi-wavelength study of the Flat Spectrum Radio Quasar PKS 1222+216, analyzing its long-term variability of radio data obtained in 2013-2020 from the iMOGABA, MOJAVE, and VLBA-BU-BLAZAR programs, along with Gamma-ray data from Fermi-LAT. We found that the radio flux densities at 15, 22, 43, and 86GHz declined exponentially by 37%-56% over a year following a Gamma-ray flare in November 2014. We estimated jet physical parameters through Gaussian model fitting of VLBA 43GHz data, identifying 10 jet components. The cooling timescales of the jet emission regions, i.e., newly ejected components C9, C10, and C11, range from 43 to 222 days, with the estimated jet viewing angles of approximately 8 degrees and magnetic field strengths of 77-134mG in the jet emission regions. Additionally, by determining the magnetic field strength at different frequencies, we found that the magnetic field scales as B {prop.to} r^(-0.3+/-0.04)^, indicating a non-equipartition condition (kr>~1) or a slow decline in magnetic field strength profile (m<1). By analyzing component ejection times, we discovered that the Gamma-ray flare in 2014 coincided with the interaction between the moving component C9 and the stationary feature A1. We estimated that the Gamma-ray emission region is located at 9.2+/-1.0pc from the core, beyond the BLR and dusty torus, suggesting that the seed photons for inverse Compton scattering originate from the jet itself, external CMB radiation, or a surrounding sheath. Our results favor a scenario where Gamma-ray emission originates further downstream from the central engine through interactions between moving and stationary components. Additionally, our study presents an alternative method for estimating magnetic field strengths in AGNs undergoing long-term synchrotron cooling based on the associated timescale.2026A&A...708A.339Jhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/708/A339CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicehttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/708/A339https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/708/A339http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/708/A339https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/708/A339https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/708/A339http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/708/A339GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/A+A/708/A339/list (List of fits images)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/708/A339/list?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/708/A339/list?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/708/A339/list?GETtext/xml+votable180.050000true186.2268821.379530.005555555555555556Associated datahttps://cdsarc.cds.unistra.fr/assocdata/?obs_collection=J/A+A/708/A3396/28083https://cdsarc.cds.unistra.fr/viz-bin/moc/J/A+A/708/A339?format=asciiGamma-rayRadiodefaultJ/A+A/708/A339/listList of fits imagesrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintRAJ2000Right Ascension of center (J2000)degpos.eq.ra;meta.mainDEJ2000Declination of center (J2000)degpos.eq.dec;meta.mainNxNumber of pixels along X-axismeta.numberintNyNumber of pixels along Y-axismeta.numberintObs.dateObservation datestime.epoch;obsnullableFreqObserved frequencyHzem.freqdoublesizeSize of FITS fileKibytephys.size;meta.fitsintFileNameName of FITS file, in subdirectory fitsmeta.id;meta.fitscharTitleTitle of the FITS filemeta.title;meta.fitscharAssocDataAssociated Data web pagemeta.ref.urlchar