# Multi-Physics of AGN Jets in the Multi-Messenger Era

## TL;DR

This paper discusses how multi-messenger observations, including neutrinos and electromagnetic signals, are revolutionizing our understanding of the physics of active galactic nuclei jets, revealing their particle acceleration and energy dissipation mechanisms.

## Contribution

It highlights the importance of multi-messenger astronomy in studying AGN jets and presents new insights into their particle acceleration and energy dissipation processes.

## Key findings

- AGN jets are confirmed as multi-messenger sources capable of accelerating hadrons to high energies.
- Multi-messenger data helps address long-standing questions about jet energy dissipation and particle acceleration.
- The era of multi-messenger astronomy will enhance understanding of AGN jet physics in the next decade.

## Abstract

Active galactic nuclei (AGN) with relativistic jets, powered by gas accretion onto their central supermassive black hole (SMBH), are unique laboratories for studying the physics of matter and elementary particles in extreme conditions that cannot be realized on Earth. For a long time since the discovery of AGN, photons were the only way to probe the underlying physical processes. The recent discovery of a very high energy neutrino, IceCube-170922A, coincident with a flaring blazar, TXS 0506+056, provides the first evidence that AGN jets are multi-messenger sources; they are capable of accelerating hadrons to very high energies, while producing non-thermal EM radiation and high-energy neutrinos. This new era of multi-messenger astronomy, which will mature in the next decade, offers us the unprecedented opportunity to combine more than one messenger to solve some long-standing puzzles of AGN jet physics: How do jets dissipate their energy to accelerate particles? What is the jet total kinetic power? Where and how do jets produce high-energy emission and neutrinos? What physical mechanisms drive the particle acceleration?