Very High Energy Gamma Rays from Ultra Fast Outflows
Abstract
Context. Ultra fast outflows (UFOs) from active galactic nuclei (AGN) are expected to lead to the formation of sub-relativistic strong shocks expanding in a dense circumnuclear medium, and thus have the potential for being efficient particle accelerators, and to be proficient sources of gamma rays and neutrinos. Aims. We investigate the detectability of a sample of nearby identified UFOs in gamma rays and neutrinos with current and next- generation instruments. Methods. We model the acceleration of particles at the strong shocks of UFOs, and estimate the associated gamma-ray and neutrino signal. We adopt our model to investigate the prospects for detection with current and next-generation observatories. Results. We find that several UFOs could be detectable in the very-high-energy (VHE) domain - for example, by the Cherenkov Telescope Array Observatory (CTAO)- even if they remain undetected by Fermi-LAT in the high-energy range. Detectability is favored for hard proton spectra (spectral index {\alpha} \lessim 3.9), high acceleration efficiencies, and amplified magnetic fields. Our results suggest that next-generation VHE observatories could detect the first gamma-ray signatures of AGN UFOs, providing a new probe of particle acceleration in sub-relativistic shocks
Cite
@article{arxiv.2603.08701,
title = {Very High Energy Gamma Rays from Ultra Fast Outflows},
author = {B. Le Nagat Neher and E. Peretti and P. Cristofari and A. Zech},
journal= {arXiv preprint arXiv:2603.08701},
year = {2026}
}
Comments
9 pages, 5 figures,accepted for publication in A&A