The ablation of gas clouds by blazar jets and the long-lasting flare in CTA 102

TL;DR

This paper investigates how interactions between gas clouds and blazar jets can produce long-lasting, intense flares, exemplified by the 2016 CTA 102 event, through a comprehensive parameter study of the model.

Contribution

It introduces a detailed model of gas cloud and jet interactions to explain prolonged blazar flares, supported by a case study of CTA 102's 2016 flare.

Findings

The model can reproduce the duration and intensity of long-lasting flares.

Interaction parameters significantly influence flare characteristics.

The 2016 CTA 102 flare is explained by cloud-jet interaction dynamics.

Abstract

Long-lasting, very bright multiwavelength flares of blazar jets are a curious phenomenon. The interaction of a large gas cloud with the jet of a blazar may serve as a reservoir of particles entrained by the jet. The size and density structure of the cloud then determine the duration and strength of the particle injection into the jet and the subsequent radiative outburst of the blazar. In this presentation, a comprehensive parameter study is provided showing the rich possibilities that this model offers. Additionally, we use this model to explain the 4-months long, symmetrical flare of the flat spectrum radio quasar CTA 102 in late 2016. During this flare, CTA 102 became one of the brightest blazars in the sky despite its large redshift of $z=1.032$.