Correlation between optical flux and polarization variations in Flat Spectrum Radio Quasars on diverse timescales

Abstract

Study of the polarization behaviour in blazars is a powerful tool to discern the role of magnetic field in the variable emission process in their relativistic jets. We present here results of our systematic investigation on the correlation between optical flux and polarization variations for eight flat-spectrum radio quasars on various timescales using data from the Steward Observatory that covers a period of $\sim$10 years. On long time scales ($\sim$several months), from a total of 79 observing cycles, in 34 observing cycles, we found a significant positive correlation between optical flux and optical polarization degree (PD), negative correlation in 3 cycles and no correlation in 42 cycles. On short time scales ($\sim$few days), in 47 out of a total of 55 epochs, we found a positive correlation between optical flux and PD, while, on the remaining 8 epochs, an anti-correlation was detected between the two quantities. Moreover, we noticed a significant positive correlation between optical and $\gamma -$ray fluxes on 14 epochs and a negative correlation between the two on one epoch. While the observed optical flux changes well fit in the shock-in-jet model, the observed changes in PD are not explainable by changes in the power-law spectral index of the relativistic electrons in the jet. Instead, the observed varied correlations between optical flux and PD could be due to multi-zone emission regions or the enhanced flux coinciding with the emergence of a new emission knot with its magnetic field either aligned or misaligned with the large scale magnetic field.

arXiv comment27 pages, 5 figures, 7 tables, accepted for publication in MNRAS main journal

References in corpus (72)

• Unified Schemes for Radio-Loud Active Galactic Nuclei
• The Large Area Telescope on the Fermi Gamma-ray Space Telescope Mission
• A Unifying View of the Spectral Energy Distributions of Blazars
• On characterising the variability properties of X-ray light curves from active galaxies
• The Spectral Energy Distribution of Fermi bright blazars
• Turbulent, Extreme Multi-Zone Model for Simulating Flux and Polarization Variability in Blazars
• Probing the Inner Jet of the Quasar PKS 1510-089 with Multi-waveband Monitoring during Strong Gamma-ray Activity
• The Sloan Digital Sky Survey Quasar Catalog: twelfth data release
• MAGIC discovery of VHE Emission from the FSRQ PKS 1222+21
• A change in the optical polarization associated with a gamma-ray flare in the blazar 3C 279
• MOJAVE: XV. VLBA 15 GHz Total Intensity and Polarization Maps of 437 Parsec-Scale AGN Jets From 1996-2017
• Improved redshifts for SDSS quasar spectra
• The unprecedented optical outburst of the quasar 3C 454.3. The WEBT campaign of 2004-2005
• The Spectral Energy Distributions of Fermi Blazars
• Photopolarimetric Monitoring of Blazars in the Optical and Near-Infrared Bands with the Kanata Telescope. I. Correlations between Flux, Color, and Polarization
• Fermi Gamma-ray Space Telescope Observations of Recent Gamma-ray Outbursts from 3C 454.3
• Similarity of the Optical-IR and Gamma-Ray Time Variability of Fermi Blazars
• RoboPol: The optical polarization of gamma-ray--loud and gamma-ray--quiet blazars
• RoboPol: First season rotations of optical polarization plane in blazars
• RoboPol: optical polarization-plane rotations and flaring activity in blazars
• Correlated variability in the blazar 3C 454.3
• RoboPol: Connection between optical polarization plane rotations and gamma-ray flares in blazars
• Blazar sequence - an artefact of Doppler boosting
• The Australia Telescope 20GHz (AT20G) Survey: analysis of the extragalactic source sample
• The Outburst of the Blazar AO 0235+164 in 2006 December: Shock-in-Jet Interpretation
• Radiative Signatures of Plasmoid-Dominated Reconnection in Blazar Jets
• Parsec-Scale Jet Polarization Properties of a Complete Sample of Active Galactic Nuclei at 43 GHz
• Intranight optical variability of radio-quiet and radio lobe dominated quasars
• Multi-wavelength variability properties of Fermi blazar S5 0716+714
• A multi-wavelength polarimetric study of the blazar CTA 102 during a Gamma-ray flare in 2012
• GRB and blazar jets shining through their stripes
• Temporal Correlations Between Optical and Gamma-ray Activity in Blazars
• Large-Amplitude Blazar Polarization Angle Swing as a Signature of Magnetic Reconnection
• Probing Blazar Emission Processes with Optical/Gamma-ray Flare Correlations
• Systematic Study of Gamma-ray bright Blazars with Optical Polarization and Gamma-ray Variability
• X-ray Intraday Variability of Five TeV Blazars with NuSTAR
• Multi-color optical monitoring of the quasar 3C 273 from 2005 to 2016
• Quasi-periodic behaviour in the optical and γ-ray light curves of blazars 3C 66A and B2 1633+38
• Multiwavelength behaviour of the blazar 3C279: decade-long study from $\gamma$-ray to radio
• Multifrequency Studies of the Peculiar Quasar 4C +21.35 During the 2010 Flaring Activity
• Two Flares with One Shock: the Interesting Case of 3C 454.3
• Multi-frequency monitoring of gamma-ray loud blazars: I. Light curves and spectral energy distributions
• Radiation and Polarization Signatures from Magnetic Reconnection in Relativistic Jets--I. A Systematic Study
• Multiwavelength behaviour of the blazar OJ 248 from radio to γ-rays
• Exploring the connection between parsec-scale jet activity and broadband outbursts in 3C 279
• Clues on High Energy Emission Mechanism from Blazar 3C 454.3 during 2015 August Flare
• Temporal correlation between the optical and γ-ray flux variations in the blazar 3C 454.3
• Long-term optical polarization variability of the tev blazar 1es~1959+650
• Investigating the multiwavelength behaviour of the flat spectrum radio quasar CTA 102 during 2013-2017
• Flare-like Variability of the Mg~II $\lambda$2798 Å Emission Line and UV Fe~II band in the Blazar CTA~102
• Fermi-Large Area Telescope observations of the brightest Gamma-ray flare ever detected from CTA 102
• Optical Polarization of 52 Radio-Loud QSOs and BL Lac Objects
• Multiwavelength Photometric and Spectropolarimetric Analysis of the FSRQ 3C 279
• Locating the gamma-ray emission site in Fermi/LAT blazars. II Multifrequency correlations
• Anti-correlated Optical Flux and Polarization Variability in BL Lac
• Multiwavelength variability study and search for periodicity of PKS 1510-089
• Long term γ -ray variability of blazars
• Flux and polarization variability of OJ 287 during early 2016 outburst
• Suzaku Observations of Luminous Quasars: Revealing the Nature of High-Energy Blazar Emission in Quiescent States
• Correlation between optical and $\gamma$-ray flux variations in bright flat spectrum radio quasars
• Broadband variability and correlation study of 3C 279 during flare of 2017-2018
• Multi-wavelength Temporal Variability of the Blazar 3C 454.3 during 2014 Activity Phase
• Simultaneous Multiwavelength and Optical Microvariability Observations of CTA 102 (PKS J2232+1143)
• CTA 102 in exceptionally high state during 2016-17
• Search for Intra-day Optical Variability in $\gamma$-ray--loud Blazars S5 0716+714 and 3C 273
• Stochastic model of optical variability of BL Lacertae
• Multiwavelength Analysis of the Variability of the Blazar 3C 273
• Multiband optical flux density and polarization microvariability study of optically bright blazars
• Optical Variability of the TeV Blazar 1ES 0806+524 on Diverse Timescales
• Multiwavelength analysis and the difference in the behavior of the spectral features during the 2010 and 2014 flaring periods of the blazar 3C 454.3
• Is there a non-stationary γ-ray emission zone 42 pc away from the 3C 279 core?
• Interpreting the variation phenomena of B2 1633+382 via the two-component model

Cited by in corpus (7)

• Gaussian Process Modeling Blazar Multiwavelength Variability: Indirectly Resolving Jet Structure
• Study of correlation between optical flux and polarization variations in BL Lac objects
• Multiwavelength analysis and the C IV λ1549 Å emission line behavior from 2008 to 2020 of the FSRQ B2 1633+382
• Flux and spectral variability of Mrk 421 during its moderate activity state using NuSTAR: Possible accretion disc contribution?
• Polarization Studies in Different Blazar Types. Part I: Correlation between Optical Brightness and Polarization Degree
• Investigating the origin of optical flares from the TeV blazar S4 0954+65
• Peculiar Behavior of Optical Polarization in Blazar 1ES 1959+650: Role of Jet Magnetic Field and Geometry