Temporal and spectral study of PKS 0208-512 during the 2019-2020 flare

Abstract

We present the temporal and spectral study of blazar PKS 0208-512, using recent flaring activity from November 2019 to May 2020, as detected by the Fermi-LAT observatory. The contemporaneous X-ray, optical/UV observations from Swift-XRT/UVOT are also used. During the activity state, 2-days binned $\gamma$-ray lightcurve shows multiple peaks indicating sub-flares. To understand the possible physical mechanisms behind flux enhancement, we divided the activity state of the source into several flux-states and carried out detailed temporal and spectral studies. Timing analysis of lightcurves suggest that peaks of sub-flares have rise and decay time on the order of days, with flux-doubling time $\sim$ 2-days. The 2-days binned $\gamma$-ray lightcurve shows double-lognormal flux distribution. The broadband spectral-energy-distribution (SED) for three selected flux states can be well fitted under synchrotron, synchrotron self-Compton (SSC) and external-Compton (EC) emission mechanisms. We obtained the physical parameters of the jet by the SED modeling and their confidence intervals through ${\chi }^2$-statistics. Our SED modeling results suggest that during quiescent-state, $\gamma$-ray spectrum can be well explained by considering the EC-scattering of infra-red (IR) photons from dusty-torus. However, $\gamma$-ray spectra corresponding to flares demand additional target photons from broad-line-region (BLR) along with IR. These suggest that during flares, the emission-region is close to the edge of BLR, while for quiescent-state the emission-region is away from BLR. The best fit results suggest that marginal increase in magnetic-field during the flaring-episode can result in the flux enhancement. This is possibly associated with the efficiency of particle acceleration during flaring-states as compared to quiescent-state.

arXiv comment14 pages, 8 figures, 5 tables, Published in MNRAS

References in corpus (60)

• Measuring Reddening with SDSS Stellar Spectra and Recalibrating SFD
• Unified Schemes for Radio-Loud Active Galactic Nuclei
• The Large Area Telescope on the Fermi Gamma-ray Space Telescope Mission
• The Swift Ultra-Violet/Optical Telescope
• Fermi Large Area Telescope Fourth Source Catalog
• Fermi Large Area Telescope Second Source Catalog
• On characterising the variability properties of X-ray light curves from active galaxies
• The extragalactic optical-infrared background radiations, their time evolution and the cosmic photon-photon opacity
• A theoretical unifying scheme for gamma-ray bright blazars
• General physical properties of bright Fermi blazars
• Blazars in the Fermi Era: The OVRO 40-m Telescope Monitoring Program
• The Third Catalog of Active Galactic Nuclei Detected by the Fermi Large Area Telescope
• Canonical high power blazars
• The power of relativistic jets is larger than the luminosity of their accretion disks
• X-ray Spectral Variability and Rapid Variability of the Soft X-ray Spectrum Seyfert 1 Galaxies Ark 564 and Ton S180
• Comptonization of Infrared Radiation from Hot Dust by Relativistic Jets in Quasars
• Log-parabolic spectra and particle acceleration in the BL Lac object Mkn 421: spectral analysis of the complete BeppoSAX wide band X-ray data set
• Constraining Emission Models of Luminous Blazar Sources
• Gamma-ray Light Curves and Variability of Bright Fermi-Detected Blazars
• The transition between BL Lac objects and Flat Spectrum Radio Quasars
• CGRaBS: An All-Sky Survey of Gamma-Ray Blazar Candidates
• Spectral Properties of Bright Fermi-detected Blazars in the Gamma-ray Band
• Fermi Gamma-ray Space Telescope Observations of the Gamma-ray Outburst from 3C 454.3 in November 2010
• Towards a physical model of dust tori in Active Galactic Nuclei - Radiative transfer calculations for a hydrostatic torus model
• An Updated Ultraviolet Calibration for the Swift/UVOT
• Rapid variability in TeV blazars: the case of PKS 2155-304
• VHE gamma-ray emission of PKS 2155-304: spectral and temporal variability
• Variability in Blazars: Clues from PKS 2155-304
• Rapid X-ray Variability of the BL Lacertae Object PKS 2155-304
• F-GAMMA: Variability Doppler factors of blazars from multiwavelength monitoring
• The minijets-in-a-jet statistical model and the RMS-flux correlation
• Blazar candidates beyond redshift 4 observed by Swift
• Log-normal flux distribution of bright Fermi blazars
• Exceptional outburst of the blazar CTA 102 in 2012: The GASP-WEBT campaign and its extension
• An Optical-Near-Infrared Outburst with No Accompanying Gamma-Rays in the Blazar PKS 0208-512
• Modelling the VHE flare of 3C 279 using one zone leptonic model
• The flux distribution of individual blazars as a key to understand the dynamics of particle acceleration
• Long-term study of Mkn 421 with the HAGAR Array of Telescopes
• Violent Hard X-ray Variability of Mrk 421 Observed by NuSTAR in 2013 April
• Evidence for two Lognormal States in Multi-wavelength Flux Variation of FSRQ PKS 1510-089
• Exploring the nature of broadband variability in the FSRQ 3C 273
• Clues on High Energy Emission Mechanism from Blazar 3C 454.3 during 2015 August Flare
• Broadband Spectral Fitting of Blazars using XSPEC
• Study on Temporal and Spectral behavior of 3C 279 during 2018 January flare
• NuSTAR perspective on high-redshift MeV blazars
• Multi-frequency variability study of Ton 599 during high activity of 2017
• On the spectral curvature of VHE blazar 1ES\,1011+496: Effect of spatial particle diffusion
• Flux Distribution of Gamma-Ray Emission in Blazars: The Example of Mrk 501
• Broadband variability and correlation study of 3C 279 during flare of 2017-2018
• NuSTAR, Swift, and GROND observations of the flaring MeV blazar: PMN J0641$-$0320
• Implications of the Anomalous Outburst in the Blazar PKS 0208-512
• Probing the gamma-ray variability in 3C279 using broadband observations
• Study of long-term flux and photon Index distributions of blazars using RXTE observations
• The Cherenkov Telescope Array: Science Goals and Current Status
• Influence of Energy-Dependent Particle Diffusion on the X-ray spectral curvature of MKN 421
• Establishing the Spectral Turnover of Blazar PKS 2155-304 as an Outcome of Radiative Losses
• Broadband study of OQ 334 during its flaring state
• Unveiling the broadband spectral and temporal properties of PKS\,0903-57 during its brightest flare
• Short-Timescale Variability of the Blazar Mrk 421 from AstroSat and Simultaneous Multi-Wavelength Observations
• INTEGRAL and Swift/XRT observations of the source PKS 0208-512

Cited by in corpus (1)

• Multi-band light curves from eccentric accreting supermassive black hole binaries