A Multi-wavelength Study on A Gamma-ray Bright AGN 1308+326 Using KVN at 22 and 43 GHz

TL;DR

This study analyzes the multi-wavelength behavior of the gamma-ray bright blazar 1308+326, revealing spectral variations, correlations between gamma-ray and radio emissions, and insights into the flare's origin and location relative to the central engine.

Contribution

It provides a detailed multi-frequency analysis of blazar 1308+326, linking radio jet activity with gamma-ray flares and estimating the emission region’s distance from the core.

Findings

Spectral variations around the 2014 gamma-ray flare.

Strong correlation between gamma-ray and 43 GHz radio emissions.

Gamma-ray flare originated 40-63 parsecs from the central engine.

Abstract

In this paper, we conduct a multi-frequency analysis of the gamma-ray bright blazar 1308+326 from February 2013 to March 2020, using the Korean VLBI Network at 22 and 43 GHz and gamma-ray data from the Fermi Large Area Telescope (LAT). Our findings reveal spectral variations around the 2014 gamma-ray flare, aligning with the shock-in-jet model. A strong correlation is observed between gamma-ray and 43 GHz emissions, with a 27-day lag in the VLBI core light curve, indicating a 50-day delay from the beginning of a specific radio flare to the gamma-ray peak. This radio flare correlates with a new jet component, suggesting the 2014 gamma-ray flare resulted from its interaction with a stationary component. Our analysis indicates the 2014 gamma-ray flare originated 40-63 parsecs from the central engine, with seed photons for the gamma-ray emission unlikely from the broad-line region.