High-resolution monitoring of parsec-scale jets in the Fermi era

TL;DR

This paper reviews high-resolution VLBI observations of parsec-scale jets in active galactic nuclei, emphasizing their connection to gamma-ray emissions observed by Fermi, and discusses recent findings on jet properties and blazar emission mechanisms.

Contribution

It provides a comprehensive overview of recent VLBI studies related to Fermi observations, highlighting new insights into jet morphology, kinematics, and polarization in blazars.

Findings

Radio and gamma-ray emission correlations identified

Jet kinematic studies reveal complex motion patterns

Magnetic field measurements inform jet emission models

Abstract

I review here the present observational efforts to study parsec-scale radio jets in active galactic nuclei with very-long-baseline interferometry (VLBI) as related to the new window to the Universe opened by the LAT instrument on-board the Fermi Gamma-Ray Space Telescope. I describe the goals and achievements of those radio studies, which aim to probe the emission properties, morphological changes and related kinematics, magnetic fields from the linear and circular polarization, etc., and I put those in the context of the radio--gamma-ray connection. Both statistical studies based on radio surveys and individual studies on selected sources are reported. Those should shed some light in the open questions about the nature of emission in blazars.