Rapid Variability of Gamma-ray Emission from Sites near the 43 GHz Cores of Blazar Jets

TL;DR

This paper investigates rapid gamma-ray variability in blazar jets, proposing a turbulent cell model to explain short timescales and emission characteristics near the 43 GHz core.

Contribution

It introduces a turbulent cell model that accounts for rapid variability and frequency-dependent emission regions in blazar jets.

Findings

A turbulent cell model explains rapid gamma-ray variability.

The model accounts for frequency-dependent emission region filling factors.

Observational data from AO 0235+164 supports the proposed model.

Abstract

Comprehensive VLBI and multi-waveband monitoring indicate that a single superluminal knot can cause a number of gamma-ray flares at different locations. However, the often very rapid variability timescale is a challenge to theoretical models when a given flare (perhaps the majority of those observed) is inferred from observations to lie near the 43 GHz core, parsecs from the central engine. We present some relevant observational results, using the BL Lac object AO 0235+164 as an example. We propose a turbulent cell model leading to a frequency-dependent filling factor of the emission region. This feature of the model can provide a solution to the timescale dilemma and other characteristics of blazar emission.