High-energy emission from jet-cloud interactions in AGNs

TL;DR

This paper investigates how interactions between clouds near the supermassive black hole and the base of jets in active galactic nuclei produce high-energy emissions, potentially explaining observed gamma-ray variability.

Contribution

It models jet-cloud interactions in AGNs and predicts their high-energy emission, providing insights into the jet base and central regions.

Findings

High-energy emission may be significant in Centaurus A.

Jet-cloud interactions could explain gamma-ray variability in M87.

Detection can reveal properties of the jet base and central black hole environment.

Abstract

Active galactic nuclei present continuum and line emission. The emission lines are originated by gas located close to the central super-massive black hole. Some of these lines are broad, and would be produced in a small region called broad-line region. This region could be formed by clouds surrounding the central black hole. In this work, we study the interaction of such clouds with the base of the jets in active galactic nuclei, and we compute the produced high-energy emission. We focus on sources with low luminosities in the inner jet regions, to avoid strong gamma-ray absorption. We find that the resulting high-energy radiation may be significant in Centaurus A. Also, this phenomenon might be behind the variable gamma-ray emission detected in M87, if very large dark clouds are present. The detection of jet-cloud interactions in active galactic nuclei would give information on the properties of the jet base and the very central regions.