J/ApJ/856/80ivo://CDS.VizieR/J/ApJ/856/80doi:10.26093/cds/vizier.18560080CDSFan X.-L.Li S.-K.Liao N.-H.Chen L.Liu H.-T.Lu K.-X.Yan D.-H.,Zhang R.-Y.Guo Q.Wu Q.Bai J.-M.2019-03-21T11:14:45Z2019-03-14T14:12:38ZCDS support team

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

cds-question@unistra.frinfrared-photometryvisible-astronomybroad-band-photometryquasarsWe present our photometric monitoring of a flat spectrum radio quasar 3C 454.3 at Yunnan observatories from 2006 to 2011. We find that the optical color of 3C 454.3 shows an obvious redder-when-brighter trend, which reaches a saturation stage when the source is brighter than 15.15mag at V band. We perform a simulation with multiple values of disk luminosity and spectral index to reproduce the magnitude-color diagram. The results show that the contamination caused by the disk radiation alone is difficult to produce the observed color variability. The variability properties during the outburst in 2009 December are also compared with {gamma}-ray data derived from the Fermi {gamma}-ray space telescope. The flux variation of these two bands follows a linear relation with F_{gamma}_{propto}F_R_^1.14+/-0.07^, which provides observational evidence for the external Compton process in 3C 454.3. Meanwhile, this flux correlation indicates that electron injection is the main mechanism for the variability origin. We also explore the variation of the flux ratio F{gamma}/FR and the detailed structures in the light curves, and discuss some possible origins for the detailed variability behaviors.2018ApJ...856...80Fhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/856/80CatalogResearchIsServedByTAP VizieR generic servicerelated-toJ/A+A/333/231 : O-M stars model atmospheres (Bessell+ 1998)J/A+A/450/39 : BVRI photometry of 8 red blazars (Gu+, 2006)J/ApJ/763/L36 : MgII and FeII flux of the blazar 3C 454.3 (Leon-Tavares+, 2013)J/ApJ/783/83 : BVRI photometry of S5 0716+714 (Liao+, 2014)J/ApJS/226/17 : BRI observations of the QSO Zw III 2 (Liao+, 2016)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/856/80https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/856/80http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/856/80https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/856/80https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/856/80http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/856/80GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapOpticalInfrareddefaultJ/ApJ/856/80/table1The daily averaged magnitude of 3C 454.3 observed at Yunnan ObservatoriesInstrInstrument (1)meta.id;instrcharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintMJD[53999.5/55881.6] Modified Julian date of observation; JD-2400000.5dtime.epochdoubleomag[13.1/17.2] Observed magnitudemagphot.magfloate_omag[0.001/0.15] Uncertainty in omagmagstat.error;phot.magfloatFilt[BVRI] Filter (B, V, R or I)meta.id;instr.filterchar