The Blazar Paradigm: Synchro-Compton Emission from Relativistic Jets

Marscher, A. P.

doi:10.1017/s0252921100044389

Cited by 2 publications

(2 citation statements)

References 27 publications

(26 reference statements)

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“…Spectral energy distributions (SED) are in the shape of a double peaked pattern. The low energy component has a peak within IR-to-X-ray range and is usually attributed to Doppler-boosted synchrotron radiation (Bregman et al 1981;Urry & Mushotzky 1982;Marscher 1998;Blandford & Königl 1979). The high energy component peak in the MeV-TeV energy range is likely produced by inverse-Compton (IC) process (Marscher et al 1992).…”

Section: Introductionmentioning

confidence: 99%

Statistical Analysis of Microvariability Properties of the Blazar S5 0716+714

Webb

et al. 2019

ApJ

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The typical blazar S5 0716+714 is very interesting due to its rapid and large amplitude variability and high duty cycle of micro-variability in optical band. We analyze the observations in I, R and V bands obtained with the 1.0m telescope at Weihai observatory of Shandong University from 2011 to 2018. The model of synchrotron radiation from turbulent cells in a jet has been proposed as a mechanism for explaining micro-variability seen in blazar light curves. Parameters such as the sizes of turbulent cells, the enhanced particle densities, and the location of the turbulent cells in the jet can be studied using this model. The model predicts a time lag between variations as observed in different frequency bands. Automatic model fitting method for micro-variability is developed, and the fitting results of our multi-frequency micro-variability observations support the model. The results show that both the amplitude and duration of flares decomposed from the micro-variability light curves confirm to the log-normal distribution. The turbulent cell size is within the range of about 5 to 55 AU, and the time lags of the micro-variability flares between the I-R and R-V bands should be several minutes. The time lags obtained from the turbulence model are consistent with the fitting statistical results, and the time lags of flares are correlated with the time lags of the whole light curve.

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Section: Introductionmentioning

confidence: 99%

Statistical Analysis of Microvariability Properties of the Blazar S5 0716+714

Webb

et al. 2019

ApJ

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“…The source brightness temperature measured from the COSMIC data ranged from 3.8 × 10 13 to 1.1 × 10 14 K (assuming that the observed variations are due to scintillation), whereas the lower limit of the source brightness temperature estimated from the VLBI radio images were found to vary between 2.7 × 10 10 and 6.9 × 10 11 K. The source brightness temperature inferred from the COSMIC data exceeds the inverse Compton limit (∼10 12 K; Kellermann & Pauliny-Toth 1969) and implies a Doppler boosting factor of >100. Estimation of Doppler factor was under the assumption of brightness temperature limited incoherent synchrotron emission (Marscher 1998). The inference of brightness temperatures that violate the inverse Compton limit strengthens the case that the radio IDV observed in PKS B1144−379 is caused by ISS.…”

Section: Source-intrinsic Variabilitymentioning

confidence: 75%

Interstellar scintillation of an extreme scintillator: PKS B1144−379

Said

Ellingsen

Bignall

et al. 2020

Monthly Notices of the Royal Astronomical Society

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The University of Tasmania Ceduna radio telescope has been used to investigate rapid variability in the radio flux density of the BL Lac object PKS B1144−379 at 6.7 GHz. High-cadence monitoring of this extreme scintillator was carried out over a period of approximately nine years, between 2003 and 2011. We have used structure functions created from the intensity time series to determine the characteristic timescale of the variability. The characteristic timescale is consistently observed to increase during certain periods of each year, demonstrating the annual cycle expected for scintillation through an interstellar scattering screen. The best-fitting annual cycle model for each year suggests that the scintillation pattern has an anisotropic structure and that the upper limit of its scattering screen is at a distance of ∼0.84 kpc. Higher anisotropy in some of the annual cycle fits suggests that changes in the intrinsic source structure might be influencing the variability timescale. We found a prominent annual cycle is only present in the variability timescale for certain years where other evidence suggests that the core is compact. From our measurements we calculated that the core angular size varied between 5.65–15.90 μas (0.05–0.13 pc). The core component was found to be at its most compact during two flares in the total flux density, which were observed in 2005 and 2008. We conclude that the long-term variability in the radio flux density of PKS B1144−379 is due to intrinsic changes in the source and that these affect our ability to measure an annual cycle in its variability time scale.

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The Blazar Paradigm: Synchro-Compton Emission from Relativistic Jets

Cited by 2 publications

References 27 publications

Statistical Analysis of Microvariability Properties of the Blazar S5 0716+714

Statistical Analysis of Microvariability Properties of the Blazar S5 0716+714

Interstellar scintillation of an extreme scintillator: PKS B1144−379

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