Modelling the γ-ray variability of 3C 273

Zheng, Y. G.; Zhang, L.; Huang, Bangrong; Kang, S. J.

doi:10.1093/mnras/stt335

Cited by 11 publications

(5 citation statements)

References 36 publications

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“…More recently, the time-dependent models were proposed to reproduce the multi-wavelength spectrum of blazar during flaring state (e.g. Kirk et al 1998;Böttcher & Chiang 2002;Li & Kusunose 2000;Tsang & Kirk 2007;Zheng & Zhang 2011;Zheng et al 2013;Zheng et al 2014). In these models, The authors argue that multi-wavelength emission comes from a small spherical region of jet plasma.…”

Section: Introductionmentioning

confidence: 99%

Modelling the multi-wavelength emission of flat-spectrum radio quasar 3C 279

Zheng

Yang

2016

Mon. Not. R. Astron. Soc.

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We employ a length-dependent conical jet model for the jet structure and emission properties of flat spectrum radio quasar 3C 279 in the steady state. In the model, ultrarelativistic leptons are injected at the base of jet and propagate along the jet structure, non-thermal photons are produced by both synchrotron emission and inverse Comtpon scattering off synchrotron photons and external soft photons at each segment of jet. We derive the total energy spectra contribution through integrating every segment. We apply the model to the quasi-simultaneous multi-wavelength observed data of two quiescent epoches. Using the observed radio data of source, we determine the length of jet L ∼ 100 pc, and magnetic field B 0 ∼ 0.1 − 1 G at the base of jet. Assuming a steady geometry of the jet structure and suitable physical parameters, we reproduce the multi-wavelength spectra during two quiescent observed epoches, respectively. Our results show that the initial γ-ray emission site takes place at ∼ 0.5 pc from black hole.

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Section: Introductionmentioning

confidence: 99%

Modelling the multi-wavelength emission of flat-spectrum radio quasar 3C 279

Zheng

Yang

2016

Mon. Not. R. Astron. Soc.

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“…As indicated in Table 1, we used the easyFermi tool to generate γ-ray light curves with 6 hr time bins before and after extracting the H states for each source. To quantitatively determine the rise and decay timescales of flux variations, we employ the following double exponential functional form to fit the time profiles of γray flares during high-activity states (Zheng et al 2013(Zheng et al , 2014Gasparyan et al 2018):…”

Section: Multiwavelength Light Curves and Sedsmentioning

confidence: 99%

Modeling the Multiwavelength Spectral Energy Distributions of the Fermi-4LAC Bright Flat-spectrum Radio Quasars

Zhou,

Zheng,

Zhu

et al. 2024

ApJ

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In this paper, we present a long-term multiwavelength investigation focusing on 12 distinct samples of Fermi-4LAC bright flat-spectrum radio quasars (FSRQs). Detailed variability and spectral analyses of γ-ray, X-ray, and ultraviolet/optical data obtained by the Fermi Large Area Telescope, the Swift X-ray Telescope, and the Swift Ultraviolet and Optical Telescope were performed over a period of about 14 yr, spanning from 2008 October to 2022 October. These analyses provide insights into characterizing the variations within different activity states. To efficiently reproduce the multiwavelength simultaneous/quasi-simultaneous spectral energy distributions (SEDs) of the samples, we propose a novel approach for constraining the model parameters. By analyzing the parameters of the energy spectral curvature (β), the peak frequency (ν pk), the peak luminosity (L pk), the Compton dominance parameter (A C), and the variability timescale (t var) in different activity states, we can estimate the values of the jet radiation region parameters for the samples. Subsequently, we utilize the synchrotron-self-Compton and external Compton processes, employing a logarithmic-parabolic spectral shape to approximate the observed spectra of the sample sources, while considering the induced regime for the physical parameters. The model results show that: (1) by effectively reproducing SEDs in various active states of bright FSRQs, the parameters within the emission region were reasonably constrained; (2) compared to other active states, the emission region of the jet exhibits a reduced radius during the high state, while the magnetic field strength increases during the low state; and (3) for bright FSRQs in a high-activity state, there is an enhancement of the Doppler factor, often exhibiting a tendency toward energy equipartition.

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“…Some studies invoked multiple emission regions in order to get more satisfactory fit (Boettcher & Baring 2019;Berger et al 2011;Prince et al 2019;Tavecchio et al 2012). Time-dependant leptonic and hadronic models were used by some authors to calculate the radiating particle distribution solving the Fokker-Planck equation considering various acceleration processes and these models are helpful to understand the evolution of blazar SED during significant flux variations (Asano & Hayashida 2018;Zheng et al 2013;Das et al 2020;Saito et al 2015).…”

Section: Introductionmentioning

confidence: 99%

Multiwavelength Study of the Quiescent States of Six Brightest Flat Spectrum Radio Quasars detected by Fermi-LAT

Roy,

Patel,

Sarkar

et al. 2021

Preprint

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The regular monitoring of flat-spectrum radio quasars (FSRQs) in 𝛾-rays by Fermi-LAT since past 12 years indicated six sources who exhibited extreme 𝛾-ray outbursts crossing daily flux of 10 −5 photons cm −2 s −1 . We obtained nearly-simultaneous multi-wavelength data of these sources in radio to 𝛾-ray waveband from OVRO, Steward Observatory, SMARTS, Swift-UVOT, Swift-XRT and Fermi-LAT. The time-averaged broadband Spectral Energy Distributions (SEDs) of these sources in quiescent states were studied to get an idea about the underlying baseline radiation processes. We modeled the SEDs using one-zone leptonic synchrotron and inverse-Compton emission scenario from broken power-law electron energy distribution inside a spherical plasma blob, relativistically moving down a conical jet. The model takes into account inverse-Compton scattering of externally and locally originated seed photons in the jet. The big blue bumps visible in quiescent state SEDs helped to estimate the accretion disk luminosities and central black hole masses. We found a correlation between the magnetic field inside the emission region and the ratio of emission region distance to disk luminosity, which implies that the magnetic field decreases with an increase in emission region distance and decrease in disk luminosity, suggesting a disk-jet connection. The high-energy index of the electron distribution was also found to be correlated with observed 𝛾-ray luminosity as 𝛾-rays are produced by high energy particles. In most cases, kinetic power carried by electrons can account for jet radiation power as jets become radiatively inefficient during quiescent states.

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Modelling the γ-ray variability of 3C 273

Cited by 11 publications

References 36 publications

Modelling the multi-wavelength emission of flat-spectrum radio quasar 3C 279

Modelling the multi-wavelength emission of flat-spectrum radio quasar 3C 279

Modeling the Multiwavelength Spectral Energy Distributions of the Fermi-4LAC Bright Flat-spectrum Radio Quasars

Multiwavelength Study of the Quiescent States of Six Brightest Flat Spectrum Radio Quasars detected by Fermi-LAT

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