On the two main classes of Active Galactic Nuclei

TL;DR

This paper argues for a shift in AGN classification from traditional radio-based labels to a physically meaningful division based on the presence of relativistic jets, advocating for the terms "jetted" and "non-jetted."

Contribution

It proposes a new classification scheme for AGN grounded in physical jet presence rather than outdated observational labels.

Findings

Traditional labels are obsolete and misleading.

Classification based on relativistic jets is more physically meaningful.

Proposes adopting 'jetted' and 'non-jetted' terminology.

Abstract

Active Galactic Nuclei (AGN) are traditionally divided empirically into two main classes: "radio-loud" and "radio-quiet" sources. These labels, which are more than fifty years old, are obsolete, misleading, and wrong. I argue that AGN should be classified based on a fundamentally physical rather than just an observational difference, namely the presence (or lack) of strong relativistic jets, and that we should use the terms "jetted" and "non-jetted" AGN instead.