On the correlation between the X-ray and gamma-ray emission in TeV blazars

Abstract

The observations of TeV blazars published recently show an unexpected quadratic or even cubic correlation between the X-ray and gamma-ray emission. A standard model of the synchrotron self-Compton emission of a compact source inside a jet is not able to explain such a correlation. Therefore, we propose an alternative scenario where the emission of at least two independent compact components is observed at the same time. We compare two different models. The first model assumes the injection of relativistic particles into a downstream region of a shock wave inside a jet that creates the emitting source. The model precisely describes the evolution of the particle energy spectrum inside the source and takes into account a light-crossing time effect for the produced radiation. The second model assumes an intrinsically constant emission of a homogeneous source that travels inside the jet along a curved trajectory, where the activity is produced simply by different values of the source's Doppler factor. To verify the two models we use recentlu published observations of Mrk 421. Our simulations show that simultaneous radiation of at least two independent sources, where the first source dominates the emission in the X-ray range and the second source radiates strongly in the gamma-ray range, can explain the observed correlations. However, the injection model provides inadequate results because it gives different values for the correlation of the rise and decay of a flare. This problem is negligible in the scenario that uses the Doppler boosting effect. Therefore, this approach yields much better results.

6 pages, 2 figures, accepted for publication in A&A

References in corpus (8)

• Multiwavelength Observations of Markarian 421 in March 2001: an Unprecedented View on the X-ray/TeV Correlated Variability
• Observations of Mkn 421 with the MAGIC Telescope
• Stochastic particle acceleration and synchrotron self--Compton radiation in TeV blazars
• Mid-Infrared Fine Structure Line Ratios in Active Galactic Nuclei Observed with Spitzer IRS: Evidence for Extinction by the Torus
• A multi-zone model for simulating the high energy variability of TeV blazars
• Long-Term X-Ray and TeV variability of Mrk 501
• Modelling rapid TeV variability of PKS 2155-304
• Constraints on the steady and pulsed very high energy gamma-ray emission from observations of PSR B1951+32/CTB 80 with the MAGIC Telescope

Cited by in corpus (15)

• TeV and Multi-wavelength Observations of Mrk 421 in 2006-2008
• The gamma-ray brightest days of the blazar 3C 454.3
• Active Galactic Nuclei under the scrutiny of CTA
• Emitting electrons spectra and acceleration processes in the jet of Mrk 421: from low state to giant flare state
• Investigation of the correlation patterns and the Compton dominance variability of Mrk 421 in 2017
• Localising the gamma-ray emission region during the June 2014 outburst of 3C 454.3
• Short-term VHE variability in blazars: PKS 2155-304
• Feasibility Study of Lense-Thirring Precession in LS I +61303
• A time dependent approach to model X-ray and $\gamma$--ray light curves of Mrk 421 observed during the flare in February 2010
• Unfolding the X-ray Spectral Curvature of Mkn 421 for Further Clues
• Multi-wavelength study of the short term TeV flaring activity from the blazar Mrk 501 observed in June 2014
• Do radiative losses determine the characteristic emission of the blazar Mkn 421?
• Correlated Short-Timescale Hard-Soft X-ray Variability of the Blazars Mrk 421 and 1ES 1959+650 using $\text{AstroSat}$
• Implications of the radio spectral index transition in LS I +61°303 for its INTEGRAL data analysis
• Core-shift and precession in the jet of LSI+61303