# Comparison between $Fermi$ Detected and non-$Fermi$ Detected Superluminal Sources

## TL;DR

This study compares superluminal active galactic nuclei detected and not detected by Fermi-LAT, revealing differences in their apparent velocities, Doppler factors, and viewing angles through statistical analysis of multi-wavelength data.

## Contribution

It provides a comprehensive statistical comparison between Fermi-detected and non-Fermi-detected superluminal AGNs, highlighting key differences in their relativistic jet properties.

## Key findings

- Fermi-detected sources have higher proper motions and Lorentz factors.
- Fermi-detected sources exhibit smaller viewing angles.
- No significant difference in co-moving viewing angles.

## Abstract

Active galactic nuclei (AGNs) have been attracting research attention due to their special observable properties. Specifically, a majority of AGNs are detected by Fermi-LAT missions, but not by Fermi-LAT, which raises the question of whether any differences exist between the two. To answer this issue, we compile a sample of 291 superluminal AGNs (189 FDSs and 102 non-FDSs) from available multi-wavelength radio, optical, and X-ray (or even $\gamma$-ray) data and Doppler factors and proper motion ($\mu$) (or apparent velocity ($\beta_{\rm{app}}$)); calculated the apparent velocity from their proper motion, Lorentz factor ($\Gamma$), viewing angle ($\phi$) and co-moving viewing angle ($\phi_{co}$) for the sources with available Doppler factor ($\delta$); and performed some statistical analyses for both types. Our study indicated that1. In terms of average values, FDSs have higher proper motions ($\mu$), apparent velocities ($\beta_{\rm app}$), Doppler factor ($\delta$), Lorentz factor ($\Gamma$), and smaller viewing angle ($\phi$). Nevertheless, there is no clear difference in co-moving viewing angles ($\phi_{\rm co}$).