Cloud ablation by a relativistic jet and the extended flare in CTA 102 in 2016 and 2017

Abstract

In late 2016 and early 2017 the flat spectrum radio quasar CTA 102 exhibited a very strong and long-lasting outburst. The event can be described by a roughly 2 months long increase of the baseline flux in the monitored energy bands (optical to $\gamma$ rays) by a factor 8, and a subsequent decrease over another 2 months back to pre-flare levels. The long-term trend was superseded by short but very strong flares, resulting in a peak flux that was a factor 50 above pre-flare levels in the $\gamma$-ray domain and almost a factor 100 above pre-flare levels in the optical domain. In this paper we explain the long-term evolution of the outburst by the ablation of a gas cloud penetrating the relativistic jet. The slice-by-slice ablation results in a gradual increase of the particle injection until the center of the cloud is reached, after which the injected number of particles decreases again. With reasonable cloud parameters we obtain excellent fits of the long-term trend.

arXiv comment9 pages, 5 figures; accepted for publication in The Astrophysical Journal

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Cited by in corpus (23)

• Radio Galaxies at VHE energies
• Flare-like Variability of the Mg~II $\lambda$2798 Å Emission Line and UV Fe~II band in the Blazar CTA~102
• Investigating the multiwavelength behaviour of the flat spectrum radio quasar CTA 102 during 2013-2017
• Fermi-Large Area Telescope observations of the brightest Gamma-ray flare ever detected from CTA 102
• Locating the gamma-ray emission region in the brightest Fermi-LAT Flat Spectrum Radio Quasars
• Variability studies and modeling of the blazar PKS 2155-304 in the light of a decade of multi-wavelength observations
• The extended flare in CTA 102 in 2016 and 2017 within a hadronic model through cloud ablation by the relativistic jet
• CTA 102 in exceptionally high state during 2016-17
• Gamma rays from jets interacting with BLR clouds in blazars
• Multiwavelength Study of the Quiescent States of Six Brightest Flat Spectrum Radio Quasars detected by Fermi-LAT
• ExHaLe-jet: An extended hadro-leptonic jet model for blazars. I. Code description and initial results
• Modeling the time variable spectral energy distribution of the blazar CTA 102 from 2008 to 2022
• Investigation of the Gamma-ray Spectrum of CTA 102 During the Exceptional Flaring State in 2016-2017
• Magnetic Field Strengths of the Synchrotron Self-Absorption Region in the Jet of CTA 102 During Radio Flares
• Simulations of Stochastic Long-Term Variability in Leptonic Models for External-Compton and Synchrotron Self-Compton Dominated Blazars
• On the Origin of Gamma-ray Flares from Bright Fermi Blazars
• Studying the influence of external photon fields on blazar spectra using a one-zone hadro-leptonic time-dependent model
• Effects of non-continuous inverse Compton cooling in blazars
• The ablation of gas clouds by blazar jets
• H.E.S.S. detection and multi-wavelength study of the $z\sim$ 1 blazar PKS 0346$-$27
• Gamma-ray flares from the jet of the blazar CTA 102 in 2016-2018
• Dissipative processes and their role in the evolution of radio galaxies
• 20 years of monitoring: PKS 2155-304 and PKS 1510-089 in the eyes of Swift and Fermi. II. PKS 1510-089 and comparison