Position angle changes of inner-jets in a sample of blazars

TL;DR

This study analyzes the variability in the inner-jet position angles of blazars using VLBA data, revealing that Fermi LAT-detected blazars exhibit greater core position angle changes and flux variability compared to non-detected ones.

Contribution

It provides the first detailed comparison of inner-jet position angle variability between LAT-detected and non-detected blazars using Gaussian model-fitting of VLBA data.

Findings

LAT-detected blazars show higher position angle changes.

LAT-detected blazars have more variable core flux densities.

Correlation between core variability and gamma-ray detection.

Abstract

We have carried out the Gaussian model-fitting to the 15 GHz VLBA cores for a sample of blazars from the MOJAVE database, analyzed the correlations in the model-fitted parameters and studied the variability properties for different group of sources. We find that the Fermi LAT-detected blazars have on average higher position angle changes of cores than the LAT non-detected blazars, and that the LAT-detected ones largely associate with more variable cores in flux density.