J/ApJS/248/8ivo://CDS.VizieR/J/ApJS/248/8doi:10.26093/cds/vizier.22480008CDSDas A.K.Prince R.Gupta N.2020-10-09T09:40:17Z2020-07-24T10:08:51ZCDS support team

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

cds-question@unistra.frquasarsgamma-ray-astronomyactive-galactic-nuclei3C 454.3 is frequently observed in the flaring state. The long-term light curve of this source has been analyzed with 9yr (2008 August - 2017 July) of data from the Fermi-LAT detector. We have identified five flares and one quiescent state. The flares have substructures with many peaks during the flaring phase. We have estimated the rise and decay time of the flares and compared with flares of other similar sources. The modeling of gamma-ray spectral energy distributions shows in most cases that a log-parabola function gives the best fit to the data. We have done time-dependent leptonic modeling of two of the flares, for which simultaneous multiwavelength data are available. These two long-lasting flares, Flare-2A and Flare-2D, continued for 95 and 133 days, respectively. We have used the average values of Doppler factor, injected luminosity in electrons, size of the emission region, and the magnetic field in the emission region in modeling these flares. The emission region is assumed to be in the broad-line region in our single-zone model. The energy losses (synchrotron, synchrotron self-Compton, external Compton) and escape of electrons from the emission region have been included while doing the modeling. Although the total jet powers required to model these flares with the leptonic model are higher compared to other sources, they are always found to be lower than the Eddington luminosity of 3C 454.3. We also select some flaring peaks and show that the time variation of the Doppler factor or the injected luminosity in electrons over short timescales can explain their light curves.2020ApJS..248....8Dhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJS/248/8CatalogResearchIsServedByTAP VizieR generic servicerelated-toB/swift : Swift Master Catalog (HEASARC, 2004-)J/A+A/436/799 : X- & gamma-ray fluxes of {gamma}-ray-loud blazars (Fan+, 2005)J/A+A/450/39 : BVRI photometry of 8 red blazars (Gu+, 2006)J/AJ/134/799 : Multiwaveband polarimetry of 15 AGN (Jorstad+, 2007)J/ApJ/712/405 : Multiwavelength obs. of 3C 454.3 III. (Vercellone+, 2010)J/ApJ/722/520 : Gamma-ray light curves of Fermi blazars (Abdo+, 2010)J/ApJ/716/30 : SED of Fermi bright blazars (Abdo+, 2010)J/ApJ/763/L36 : MgII and FeII flux of the blazar 3C 454.3 (Leon-Tavares+, 2013)J/ApJS/218/23 : Fermi LAT third source catalog (3FGL) (Acero+, 2015)J/ApJS/223/15 : 8yr INTEGRAL/IBIS soft gamma-ray source obs. (Bird+, 2016)J/ApJS/224/26 : SEDs of Roma BZCAT blazars (Mao+, 2016)J/ApJ/833/77 : gamma-ray bright blazars optical polarization (Itoh+, 2016)J/ApJ/851/33 : Multi-wavelength analysis of CGRaBS blazars (Paliya+, 2017)J/ApJ/856/80 : 6-yr optical monitoring of the FSRQ 3C 454.3 (Fan+, 2018)J/ApJ/866/137 : Bright blazars variability brightness temp. (Liodakis+, 2018)J/A+A/609/A68 : Full-Stokes polarimetry of 5 radio sources (Myserlis+, 2018)J/A+A/626/A60 : F-GAMMA 2.64-43GHz radio data over 2007-2015 (Angelakis+, 2019)J/ApJS/247/33 : The Fermi LAT fourth source catalog (4FGL) (Abdollahi+, 2020)http://fermi.gsfc.nasa.gov/cgi-bin/ssc/LAT/LATDataQuery.cgi : Fermi/LAT datahttp://heasarc.gsfc.nasa.gov/ : HEASARC home pagehttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJS/248/8https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJS/248/8http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJS/248/8https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJS/248/8https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJS/248/8http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJS/248/8GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapGamma-raydefaultJ/ApJS/248/8/table1Rising and Decay time for given peak time and peak flux which is calculated by temporal fitting of the light curves with the sum of an exponential functionFlareFlare identifier code (1)meta.codecharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintt0[54719.1/57743.4] Modified Julian Date of peak timedtime.epoch;stat.maxfloatF0[3.31/80.41] Peak flux1e-06ph.cm**-2.s**-1phot.flux;stat.maxfloate_F0[0.28/5.92] Uncertainty in F01e-06ph.cm**-2.s**-1stat.errorfloatTr[2.83/114.94] Rising timehtime.epochfloate_Tr[0.78/16.77] Uncertainty in Trhstat.errorfloatTd[3.16/100.13] Decay timehtime.epochfloate_Td[0.58/17.67] Uncertainty in Tdhstat.errorfloat