Gamma-ray flares from the jet of the blazar CTA 102 in 2016-2018

Abstract

CTA 102 is a $\gamma$-ray bright blazar that exhibited multiple flares in observations by the Large Area Telescope on board the Fermi Gamma-Ray Space Telescope during the period of 2016-2018. We present results from the analysis of multi-wavelength light curves aiming at revealing the nature of $\gamma$-ray flares from the relativistic jet in the blazar. We analyse radio, optical, X-ray, and $\gamma$-ray data obtained in a period from 2012 September 29 to 2018 October 8. We identify six flares in the $\gamma$-ray light curve, showing a harder-when-brighter-trend in the $\gamma$-ray spectra. We perform a cross-correlation analysis of the multi-wavelength light curves. We find nearly zero time lags between the $\gamma$-ray and optical and X-ray light curves, implying a common spatial origin for the emission in these bands. We find significant correlations between the $\gamma$-ray and radio light curves as well as negative/positive time lags with the $\gamma$-ray emission lagging/leading the radio during different flaring periods. The time lags between $\gamma$-ray and radio emission propose the presence of multiple $\gamma$-ray emission sites in the source. As seen in 43 GHz images from the Very Long Baseline Array, two moving disturbances (or shocks) were newly ejected from the radio core. The $\gamma$-ray flares from 2016 to 2017 are temporally coincident with the interaction between a traveling shock and a quasi-stationary one at $\sim$0.1 mas from the core. The other shock is found to emerge from the core nearly simultaneous with the $\gamma$-ray flare in 2018. Our results suggest that the $\gamma$-ray flares originated from shock-shock interactions.

arXiv comment14 pages, 15 figures, 4 tables, accepted for publication in A&A

References in corpus (83)

• emcee: The MCMC Hammer
• 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
• Central Masses and Broad-Line Region Sizes of Active Galactic Nuclei. II. A Homogeneous Analysis of a Large Reverberation-Mapping Database
• The Burst Alert Telescope (BAT) on the Swift MIDEX Mission
• Fermi Large Area Telescope Fourth Source Catalog
• Fermi Large Area Telescope Second Source Catalog
• Fermi Large Area Telescope First Source Catalog
• On characterising the variability properties of X-ray light curves from active galaxies
• A Cosmology Calculator for the World Wide Web
• Relativistic Jets in Active Galactic Nuclei
• AGN Dusty Tori: II. Observational Implications of Clumpiness
• Polarimetric Observations of 15 Active Galactic Nuclei at High Frequencies: Jet Kinematics from Bimonthly Monitoring with the Very Long Baseline Array
• Studies in Astronomical Time Series Analysis. VI. Bayesian Block Representations
• On Uncertainties in Cross-Correlation Lags and the Reality of Wavelength-Dependent Continuum Lags in Active Galactic Nuclei
• Blazars in the Fermi Era: The OVRO 40-m Telescope Monitoring Program
• Structured jets in TeV BL Lac objects and radiogalaxies
• Constraints on the Physical Parameters of TeV Blazars
• Measuring the broadband power spectra of active galactic nuclei with RXTE
• Doppler factors, Lorentz factors and viewing angles for quasars, BL Lacertae objects and radio galaxies
• Constraining Emission Models of Luminous Blazar Sources
• Kinematics of Parsec-Scale Jets of Gamma-Ray Blazars at 43~GHz within the VLBA-BU-BLAZAR Program
• A change in the optical polarization associated with a gamma-ray flare in the blazar 3C 279
• Generating artificial light curves: Revisited and updated
• Flaring Behavior of the Quasar 3C~454.3 across the Electromagnetic Spectrum
• Location of gamma-ray Flare Emission in the Jet of the BL Lacertae Object OJ287 more than 14pc from the Central Engine
• Blazar spectral variability as explained by a twisting inhomogeneous jet
• The structure and emission model of the relativistic jet in the quasar 3C 279 inferred from radio to high-energy gamma-ray observations in 2008-2010
• Detection of significant cm to sub-mm band radio and gamma-ray correlated variability in Fermi bright blazars
• Time-correlation between the radio and gamma-ray activity in blazars and the production site of the gamma-ray emission
• A method for the estimation of the significance of cross-correlations in unevenly sampled red-noise time series
• Constraining the limiting brightness temperature and Doppler factors for the largest sample of radio bright blazars
• Kinematics of Parsec-Scale Jets of Gamma-Ray Bright Blazars at 43 GHz during Ten Years of the VLBA-BU-BLAZAR Program
• On the Location of the Gamma-ray Emission in the 2008 Outburst in the BL Lacertae Object AO 0235+164 through Observations across the Electromagnetic Spectrum
• Radio/gamma-ray time delay in the parsec-scale cores of active galactic nuclei
• Fermi Large Area Telescope and multi-wavelength observations of the flaring activity of PKS 1510-089 between 2008 September and 2009 June
• Radio to gamma-ray variability study of blazar S5 0716+714
• Significant core shift variability in parsec-scale jets of active galactic nuclei
• Emission from Hot Dust in the Infrared Spectra of Gamma-ray Bright Blazars
• Relativistic Outflow Drives Gamma-Ray Emission in 3C345
• Hubble Space Telescope ultraviolet spectroscopy of blazars: emission lines properties and black hole masses
• The connection between gamma-ray emission and millimeter flares in Fermi/LAT blazars
• POLAMI: Polarimetric Monitoring of Active Galactic Nuclei at Millimetre Wavelengths. III. Characterisation of total flux density and polarisation variability of relativistic jets
• POLAMI: Polarimetric Monitoring of Active Galactic Nuclei at Millimetre Wavelengths. I. The program, calibration, and calibrators data products
• Constraints on minimum electron Lorentz factor and matter content of jets for a sample of bright Fermi blazars
• A multi-wavelength polarimetric study of the blazar CTA 102 during a Gamma-ray flare in 2012
• Through The Ring Of Fire: $\gamma$-Ray Variability In Blazars By A Moving Plasmoid Passing A Local Source Of Seed Photons
• Temporal Correlations Between Optical and Gamma-ray Activity in Blazars
• Multiwavelength Cross-Correlations and Flaring Activity in Bright Blazars
• Probing Blazar Emission Processes with Optical/Gamma-ray Flare Correlations
• A connection between $\gamma$-ray and parsec-scale radio flares in the blazar 3C 273
• Locating the gamma-ray emission site in Fermi/LAT blazars from correlation analysis between 37 GHz radio and gamma-ray light curves
• Catching the radio flare in CTA 102: II. VLBI kinematic analysis
• 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
• POLAMI: Polarimetric Monitoring of Active Galactic Nuclei at Millimetre Wavelengths. II. Widespread circular polarisation
• Unravelling the complex behavior of Mrk 421 with simultaneous X-ray and VHE observations during an extreme flaring activity in April 2013
• Comprehensive Monitoring of Gamma-ray Bright Blazars. I. Statistical Study of Optical, X-ray, and Gamma-ray Spectral Slopes
• Synchrotron emission in the fast cooling regime: which spectra can be explained?
• On the multi-wavelength Emission from CTA 102
• A peculiar multi-wavelength flare in the Blazar 3C 454.3
• Connection between inner jet kinematics and broadband flux variability in the BL Lac object S5 0716+714
• KVN observations suggest multiple $\gamma$-ray emission regions in 3C 84
• Exploring the connection between parsec-scale jet activity and broadband outbursts in 3C 279
• Cloud ablation by a relativistic jet and the extended flare in CTA 102 in 2016 and 2017
• The magnetic field structure in CTA 102 from high resolution mm-VLBI observations during the flaring state in 2016-2017
• Investigating the multiwavelength behaviour of the flat spectrum radio quasar CTA 102 during 2013-2017
• Fermi-Large Area Telescope observations of the brightest Gamma-ray flare ever detected from CTA 102
• A decade of joint MOJAVE-Fermi AGN monitoring: localisation of the gamma-ray emission region
• Radio Variability and Random Walk Noise Properties of Four Blazars
• The connection between the parsec-scale radio jet and gamma-ray flares in the blazar 1156+295
• Broadband variability and correlation study of 3C 279 during flare of 2017-2018
• On the location of the supermassive black hole in CTA 102
• The extended flare in CTA 102 in 2016 and 2017 within a hadronic model through cloud ablation by the relativistic jet
• CTA 102 in exceptionally high state during 2016-17
• On the origin of the gamma-ray/optical lags in luminous blazars
• The long-term centimeter variability of active galactic nuclei: A new relation between variability timescale and accretion rate
• Imaging and variability studies of CTA~102 during the 2016 January $\gamma$-ray flare
• Exploring the Variability of the Flat Spectrum Radio Source 1633+382. I. Phenomenology of the Light Curves
• Modeling the time variable spectral energy distribution of the blazar CTA 102 from 2008 to 2022
• Investigation of the Gamma-ray Spectrum of CTA 102 During the Exceptional Flaring State in 2016-2017
• Magnetic Field Strengths of the Synchrotron Self-Absorption Region in the Jet of CTA 102 During Radio Flares

Cited by in corpus (1)

• Minijets and Broken Stationarity in a Blazar : Novel Insights into the Origin of $\gamma$-ray Variability in CTA 102