Long-term multi-wavelength variations of Fermi blazar 3C 279

Abstract

The long-term optical, X-ray and $\gamma$-ray data of blazar 3C 279 have been compiled from $Swift$-XRT, $RXTE$ PCA, $Fermi$-LAT, SMARTS and literature. The source exhibits strong variability on long time scales. Since 1980s to now, the optical $R$ band light curve spans above 32 yr, and a possible 5.6-yr-long quasi-periodic variation component has been found in it. The optical spectral behavior has been investigated. In the optical band, the mean spectral index is -1.71. The source exhibits an obvious special spectral behavior. In the low state, the source shows a clear bluer-when-brighter behavior in a sense that the optical spectrum turns harder (flatter) when the brightness increases. While in the high state, the optical spectrum is stable, that means the source spectral index does not vary with the brightness. The correlation analysis has been performed among optical, X-ray and $\gamma$-ray energy bands. The result indicates that the variations of $\gamma$-ray and X-ray bands are well correlated without time delay on the time scale of days, and their variations exhibit weak correlations with those of optical band. The variations, especial outbursts, are simultaneous, but the magnitude of variations is disproportionate. The detailed analysis reveals that the main outbursts exhibit strong correlations in different $\gamma$-ray, X-ray and optical bands.

arXiv comment17 pages, 13 figures. Accepted by Research in Astron. Astrophys.(RAA)

References in corpus (43)

• Maps of Dust IR Emission for Use in Estimation of Reddening and CMBR Foregrounds
• Unified Schemes for Radio-Loud Active Galactic Nuclei
• The Large Area Telescope on the Fermi Gamma-ray Space Telescope Mission
• On Uncertainties in Cross-Correlation Lags and the Reality of Wavelength-Dependent Continuum Lags in Active Galactic Nuclei
• Very-High-Energy Gamma Rays from a Distant Quasar: How Transparent Is the Universe?
• A change in the optical polarization associated with a gamma-ray flare in the blazar 3C 279
• SMARTS optical and infrared monitoring of 12 gamma-ray bright blazars
• Multiwavelength Observations of a Dramatic High Energy Flare in the Blazar 3C 279
• Optical and radio behaviour of the BL Lacertae object 0716+714
• Rapid Variability of Blazar 3C 279 during Flaring States in 2013-2014 with Joint Fermi-LAT, NuSTAR, Swift, and Ground-Based Multi-wavelength Observations
• 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
• The unprecedented optical outburst of the quasar 3C 454.3. The WEBT campaign of 2004-2005
• Correlated Multi-Waveband Variability in the Blazar 3C~279 from 1996 to 2007
• Photopolarimetric Monitoring of Blazars in the Optical and Near-Infrared Bands with the Kanata Telescope. I. Correlations between Flux, Color, and Polarization
• Detection of significant cm to sub-mm band radio and gamma-ray correlated variability in Fermi bright blazars
• Swift X-ray Telescope Monitoring of Fermi-LAT Gamma Ray Sources of Interest
• Similarity of the Optical-IR and Gamma-Ray Time Variability of Fermi Blazars
• Results of WEBT, VLBA and RXTE monitoring of 3C 279 during 2006-2007
• Long-term optical monitoring of TeV emitting Blazars
• Quasi-periodicities at year-like timescales in Blazars
• The Katzman Automatic Imaging Telescope Gamma-Ray Burst Alert System, and Observations of GRB 020813
• Coordinated Fermi/Optical Monitoring of Blazars and the Great 2009 September Gamma-ray Flare of 3C 454.3
• Multi-wavelength observations of 3C 279 during the extremely bright gamma-ray flare in 2014 March-April
• The WEBT Campaign on the Blazar 3C279 in 2006
• Quasi-periodicities of PKS 2155-304
• Day-Scale Variability of 3C 279 and Searches for Correlations in Gamma-Ray, X-Ray, and Optical Bands
• Quasi-periodicities of BL Lac Objects
• Temporal Correlations Between Optical and Gamma-ray Activity in Blazars
• Full Spectral Survey of Active Galactic Nuclei in the Rossi X-ray Timing Explorer Archive
• 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
• A Consolidated Framework of the Color Variability in Blazars: Long-Term Optical/Near-Infrared Observations of 3C 279
• Optical quasi-periodic oscillation and color behavior of blazar PKS 2155-304
• MAGIC observations and multifrequency properties of the Flat Spectrum Radio Quasar 3C 279 in 2011
• Long-term optical-infrared color variability of blazars
• Study on Temporal and Spectral behavior of 3C 279 during 2018 January flare
• Broadband variability and correlation study of 3C 279 during flare of 2017-2018
• The Multiple Timescales of Optical Variability of the Blazar 3C 279 During the 2001-2002 Outburst
• On the origin of the gamma-ray/optical lags in luminous blazars
• Multi-band behaviour of the TeV blazar PG 1553+113 in optical range on diverse timescales
• The gamma-ray and Optical Variability Analysis of the BL Lac Object 3FGL J0449.4-4350
• Optical polarimetric and multiwavelength flaring activity of blazar 3C279

Cited by in corpus (1)

• Study of variability in long-term multiwavelength optical lightcurves of blazar AO 0235+164