Understanding Jets from Sources Straddling the Fanaroff-Riley Divide

TL;DR

This study analyzes hybrid sources exhibiting both FRI and FRII jet features using multi-wavelength observations, aiming to clarify the Fanaroff-Riley dichotomy and the nature of hybrid jets.

Contribution

It provides new observational data and analysis of hybrid sources, exploring their radio power, jet asymmetry, and emission mechanisms to understand jet morphology diversity.

Findings

Most hybrid sources have FRII-like radio power.

X-ray jets are on the same side as VLBI jets, indicating relativistic boosting.

IC/CMB is likely the dominant X-ray emission mechanism.

Abstract

Results from Chandra-HST-VLA observations of 13 hybrid sources are presented. Data from ten sources in the literature are analysed along with new data from three hybrid blazars belonging to the MOJAVE sample. Studies of such hybrid sources displaying both FRI and FRII jet characteristics could provide the key to resolving the long-standing Fanaroff-Riley dichotomy issue. A majority of the 13 hybrid sources show FRII-like total radio powers, i.e., they are "hybrid" in radio morphology but not in total radio power. VLBI observations of ten of the 13 sources show that the X-ray jet is on the same side as the one-sided VLBI jet. X-rays are therefore emitted from relativistically-boosted approaching jets. This is consistent with the X-ray emission being IC/CMB in origin in the majority of sources. It is not completely clear from our study that asymmetries in the surrounding medium can create hybrid sources. Hybrid radio morphologies could also be indicative of intrinsically asymmetric jets.