To explain X-ray spectra of active galactic nuclei (AGN), non-thermal activity in AGN coronae such as pair cascade models has been extensively discussed in the past literature. Although X-ray and gamma-ray observations in the 1990s disfavored such pair cascade models, recent millimeter-wave observations of nearby Seyferts establish the existence of weak non-thermal coronal activity. Besides, the IceCube collaboration reported NGC 1068, a nearby Seyfert, as the hottest spot in their 10-yr survey. These pieces of evidence are enough to investigate the non-thermal perspective of AGN coronae in depth again. This article summarizes our current observational understandings of AGN coronae and describes how AGN coronae generate high-energy particles. We also provide ways to test the AGN corona model with radio, X-ray, MeV gamma-ray, and high-energy neutrino observations.
@article{arxiv.2105.08948,
title = {Gamma-ray and Neutrino Signals from Accretion Disk Coronae of Active Galactic Nuclei},
author = {Yoshiyuki Inoue and Dmitry Khangulyan and Akihiro Doi},
journal= {arXiv preprint arXiv:2105.08948},
year = {2021}
}
Comments
Invited review in Galaxies special issue "Searching for Astrophysical Sources of Cosmic Rays, Gamma-Rays and Neutrinos: Real-Time Multimessenger Programs and Theoretical Models". This paper is based on our previous papers arXiv:1904.00554 & 1909.02239