Testing relativistic boost as the cause of gamma-ray quasi-periodic oscillation in a blazar

Abstract

The mechanism for producing gamma-ray quasi-periodic oscillation (QPO) in blazar is unknown. One possibility is the geometric model, in which without the need for intrinsic quasi-periodic variation, the relativistic Doppler factor changes periodically, resulting in observed gamma-ray QPO. We propose a method to test this geometric model. We analyze the {\it Fermi}-LAT data of PG 1553+113 spanning from 2008 August until 2018 February. According to 29 four-month average spectral energy distributions (SEDs) in the energy range of 0.1-300 GeV, we split the {\it Fermi}-LAT energy range into three bands: 0.1-1 GeV, 1-10 GeV, and 10-300 GeV. The spectrum in each energy range can be successfully fitted by a power-law. The light curves and photon indices in the three energy ranges are obtained. Then, light curves in three narrow energy ranges, i.e., 0.2-0.5 GeV, 2-5 GeV and 20- 40 GeV, are constructed, and the relative variability amplitudes in the three narrow energy ranges are calculated. A discrete-correlation analysis is performed for the light curves. Our results indicate that (i) the light curves in the different energy ranges follow the same pattern showed in the light curve above 0.1 GeV; (ii) the three groups of photon indices in the energy ranges of 0.1-1 GeV, 1-10 GeV, and 10-300 GeV keep nearly constant; (iii) the ratio between relative variability amplitudes in different narrow energy ranges are equal (within their errors) to the prediction by the Doppler effect. Our results support the scenario of the relativistic boost producing the gamma-ray QPO for PG 1553+113.

arXiv commentAccepted by ApJ

References in corpus (26)

• Unified Schemes for Radio-Loud Active Galactic Nuclei
• On characterising the variability properties of X-ray light curves from active galaxies
• X-ray Spectral Variability and Rapid Variability of the Soft X-ray Spectrum Seyfert 1 Galaxies Ark 564 and Ton S180
• Gamma-ray Light Curves and Variability of Bright Fermi-Detected Blazars
• Multiwavelength Evidence for Quasi-periodic Modulation in the Gamma-ray Blazar PG 1553+113
• Blazar spectral variability as explained by a twisting inhomogeneous jet
• Relativistic boost as the cause of periodicity in a massive black-hole binary candidate
• On the geometrical origin of periodicity in blazar-type sources
• A method for the estimation of the significance of cross-correlations in unevenly sampled red-noise time series
• Quasi-periodicities at year-like timescales in Blazars
• A model for periodic blazars
• Helical jets in blazars. Interpretation of the multifrequency long-term variability of AO 0235+16
• The Blazar PG 1553+113 as a Binary System of Supermassive Black Holes
• Parsec-scale jet precession in BL Lacertae (2200+420)
• Revisiting Quasi-Periodic modulation in $\gamma$-ray Blazar PKS 2155-304 with Fermi Pass 8 data
• Quasi-periodicities of PKS 2155-304
• A search for cyclical sources of gamma-ray emission on the period range from days to years in the Fermi-LAT sky
• Gamma-ray and optical oscillations in the blazar PKS 0537-441
• Jet precession driven by a supermassive black hole binary system in the BL Lac object PG 1553+113
• Testing the relativistic Doppler boost hypothesis for supermassive black hole binary candidates
• A $\gamma$-ray Quasi-Periodic modulation in the Blazar PKS 0301$-$243?
• Searching for Correlations in Simultaneous X-ray and UV Emission in the Narrow-line Seyfert 1 galaxy 1H 0707-495
• On the Dynamics and Structure of Three-Dimensional Trans-Alfvenic Jets
• The WEBT campaign on the BL Lac object PG 1553+113 in 2013. An analysis of the enigmatic synchrotron emission
• Possible Quasi-Periodic modulation in the z = 1.1 $\gamma$-ray blazar PKS 0426-380
• Multiple Wavelength Variability and Quasi-Periodic Oscillation of PMN J0948+0022

Cited by in corpus (10)

• Evaluating Quasi-Periodic Variations in the $\gamma$-ray Lightcurves of Fermi-LAT Blazars
• Gaussian Process Modeling $Fermi$-LAT $\gamma$-ray Blazar Variability: A Sample of Blazars with $\gamma$-ray Quasi-periodicities
• A parsec-scale wobbling jet in the high-synchrotron peaked blazar PG 1553+113
• A Quasi-periodic Oscillation in the gamma-ray Emission from the Non-blazar Active Galactic Nucleus PKS 0521-36
• Searching for Quasi-Periodic Modulations in $\gamma$-ray Active Galactic Nuclei
• Periodic Gamma-ray Modulation of the blazar PG 1553+113 Confirmed by Fermi-LAT and Multi-wavelength Observations
• The gamma-ray and Optical Variability Analysis of the BL Lac Object 3FGL J0449.4-4350
• The X-ray outburst of PG 1553+113: A precession effect of two jets in the supermassive black hole binary system
• Highly Variable $\gamma$-Ray Emission of CTD 135 and Implications for its Compact Symmetric Structure
• Three Cases of Optical Periodic Modulation in Active Galactic Nuclei