The Long-Lasting Activity in the Flat Spectrum Radio Quasar (FSRQ) CTA 102

Michael Zacharias,Alicja Wierzcholska,Felix Jankowsky,Jean-Philippe Lenain,Stefan Wagner,Markus Böttcher

doi:10.3390/galaxies7010034

Abstract

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.

Highlights

Detailed monitoring across the electromagnetic spectrum, such as the programs by, e.g., Fermi-LAT in the high energy (HE) γ-ray domain or ATOM at optical frequencies
The data analysis has been done by Zacharias et al [9,15], and the reader is referred to these papers for details
They indicate correlated behavior between the the optical, X-ray, and γ-ray fluxes. This strongly suggests that the emission is co-spatial

Summary

Introduction

Detailed monitoring across the electromagnetic spectrum, such as the programs by, e.g., Fermi-LAT in the high energy (HE) γ-ray domain or ATOM at optical frequencies Flux variations up to factors 100 are observed, which usually happen on shorter time scales. While this seems to be a common rule that bright flares tend to be short, there can be exceptions. One of these exception is the blazar CTA 102, which is a flat spectrum radio quasar (FSRQ)

Results

Discussion

Conclusion