Flux and Spectral Variation Characteristics of 3C 454.3 at the GeV Band

Abstract

We analyze the long-term lightcurve of 3C 454.3 observed with Fermi/LAT and investigate its relation to the flux in the radio, optical, and X-ray bands. By fitting the 1-day binned GeV lightcurve with multiple Gaussian function (MGF), we propose that the typical variability timescale in the GeV band is 1--10 days. The GeV flux variation is accompanied by the spectral variation characterized as flux-tracking, i.e., "harder when brighter". The GeV flux is correlated with the optical and X-ray fluxes, and a weak correlation between gamma-ray flux and radio flux is also observed. The gamma-ray flux is not correlated with the optical linear polarization degree for the global lightcurves, but they show a correlation for the lightcurves before MJD 56000. The power density spectrum of the global lightcurve shows an obvious turnover at ~7.7 days, which may indicate a typical variability timescale of 3C 454.3 in the gamma-ray band. This is also consistent with the derived timescales by fitting the global lightcurve with MGF. The spectral evolution and an increase of the optical linear polarization degree along with the increase of the gamma-ray flux may indicate that the radiation particles are accelerated and the magnetic field is ordered by the shock processes during the outbursts. In addition, the nature of 3C 454.3 may be consistent with the self-organized criticality system, similar to Sagittarius A, and thus the outbursts are from plasmoid ejections driven by magnetic reconnection. This may further support the idea that the jet radiation regions are magnetized.

29 pages, 9 figures, accepted for publication in RAA

References in corpus (14)

• The Internal-Collision-Induced Magnetic Reconnection and Turbulence (ICMART) Model of Gamma-Ray Bursts
• The Third Catalog of Active Galactic Nuclei Detected by the Fermi Large Area Telescope
• 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
• Multiwavelength Observations of Markarian 421 in March 2001: an Unprecedented View on the X-ray/TeV Correlated Variability
• Rapid variability in TeV blazars: the case of PKS 2155-304
• X-ray spectral evolution of TeV BL Lac objects: eleven years of observations with BeppoSAX, XMM-Newton and SWIFT satellites
• The X-ray Flux Distribution of Sagittarius A* as Seen by Chandra
• Fermi-LAT Observations of the 2014 May-July outburst from 3C 454.3
• Statistics of X-ray flares of Sagittarius A*: evidence for solar-like self-organized criticality phenomenon
• On the origin of the hard X-Ray excess of high-synchrotron-peaked BL Lac object Mrk 421
• Universal Behavior of X-ray Flares from Black Hole Systems
• Discovery of $\gamma$-ray emission from the radio-intermediate quasar III Zw 2: violent jet activity with intraday $\gamma$-ray variability
• Similarity of Jet Radiation between Flat Spectrum Radio Quasars and GeV Narrow-Line Seyfert 1 Galaxies: A Universal $\delta$-$L_{\mathrm{c}}$ Correlation

Cited by in corpus (6)

• Jet Properties of Compact Steep-Spectrum Sources and an Eddington-Ratio-Driven Unification Scheme of Jet Radiation in Active Galactic Nuclei
• 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
• Diversity of gamma-ray and Radio Variabilities of Bright Blazars and Implications for gamma-ray Emission Location
• On the origin of GeV spectral break for Fermi blazars: 3C 454.3
• Cosmological evolution of quasar radio emission in the view of multifractality
• Fast Optical Variability of the TeV Blazar PKS 1725+123 Observed by SVOM-VT and Insights from Multi-wavelength Follow-up Observations