Jet properties of FR0 radio galaxies: need for VLBI data

TL;DR

This paper emphasizes the importance of high-resolution VLBI observations to better understand the jet structures of FR0 radio galaxies, which are abundant but poorly studied, and presents preliminary results from an ongoing observational campaign.

Contribution

It highlights the need for more VLBI data on FR0s and provides initial findings suggesting jet direction changes at different scales.

Findings

Preliminary data indicate possible jet direction changes.

FR0s may have complex jet structures at different scales.

High-resolution observations are crucial for understanding FR0 jet physics.

Abstract

Fanaroff-Riley (FR) type 0 radio galaxies are a subclass of radio-loud active galactic nuclei (AGN) that lack extended kpc-scale jets, different from the classical FRI and FRII radio galaxies. They constitute the most abundant population of radio galaxies in the local Universe (z<0.1), yet remain largely unexplored. VLBI observations of a limited number of FR0s demonstrated that their central supermassive black hole (SMBH) are able to lunch mostly two-sided jets, with mildly relativistic bulk speed. In this work, we highlight the need of further high-resolution radio observations to probe the jet structures of these compact radio galaxies, by showing exploratory results of our EVN+eMERLIN observation campaign of FR0s. A preliminary analysis of these recent data reveals a possible change of the jet direction at different scales. We shortly discuss their physical conditions to explain the observed jet compactness, stressing the role of the SMBH spin vector in shaping their radio morphology