The Long-Lasting Activity in the Flat Spectrum Radio Quasar (FSRQ) CTA 102
Michael Zacharias,
Markus Böttcher,
Felix Jankowsky,
Jean-Philippe Lenain,
Stefan J. Wagner,
Alicja Wierzcholska
Affiliations
Michael Zacharias
Ruhr Astroparticle and Plasma Physics Center (RAPP Center), Insitut für theoretische Physik IV, Ruhr-Universität Bochum, D-44780 Bochum, Germany
Markus Böttcher
Centre for Space Research, North-West University, Potchefstroom 2520, South Africa
Felix Jankowsky
Landessternwarte, Universität Heidelberg, Königstuhl, D-69117 Heidelberg, Germany
Jean-Philippe Lenain
Sorbonne Université, Université Paris Diderot, Sorbonne Paris Cité, CNRS/IN2P3, Laboratoire de Physique Nucléaire et de Hautes Energies, LPNHE, 4 Place Jussieu, F-75252 Paris, France
Stefan J. Wagner
Landessternwarte, Universität Heidelberg, Königstuhl, D-69117 Heidelberg, Germany
Alicja Wierzcholska
Institute of Nuclear Physics, Polish Academy of Sciences, PL-31342 Krakow, Poland
The flat spectrum radio quasar CTA 102 ( z = 1 . 032 ) went through a tremendous phase of variability. Since early 2016 the gamma-ray flux level has been significantly higher than in previous years. It was topped by a four month long giant outburst, where peak fluxes were more than 100 times higher than the quiescence level. Similar trends are observable in optical and X-ray energies. We have explained the giant outburst as the ablation of a gas cloud by the relativistic jet that injects additional matter into the jet and can self-consistently explain the long-term light curve. Here, we argue that the cloud responsible for the giant outburst is part of a larger system that collides with the jet and is responsible for the years-long activity in CTA 102.
