# High-Energy Gamma Rays and Neutrinos from Nearby Radio Galaxies

## TL;DR

This paper models gamma-ray and neutrino emissions from nearby radio galaxies, suggesting they could be significant sources of high-energy neutrinos detectable in the future, based on multi-messenger astrophysics data.

## Contribution

It provides a detailed analysis of gamma-ray spectra from four radio galaxies and predicts associated neutrino fluxes, considering electromagnetic cascades and cosmic-ray interactions.

## Key findings

- Predicted neutrino fluxes are close to current detection sensitivities.
- Gamma-ray spectra are consistent with cosmic-ray interaction models.
- Future neutrino detections from radio galaxies are promising.

## Abstract

Multi-messenger data suggest that radio galaxies (i.e. non-blazar active galaxies) are perhaps the most likely class of sources for the diffuse flux of high-energy neutrinos reported by the IceCube Collaboration. In this study, we consider the gamma-ray spectrum observed from four nearby radio galaxies (Centaurus A, PKS 0625-35, NGC 1275 and IC 310) and constrain the intensity and spectral shape of the emission injected from these sources, accounting for the effects of attenuation and contributions from electromagnetic cascades (initiated both within the radio galaxy itself and during extragalactic propagation). Assuming that this gamma-ray emission is generated primarily through the interactions of cosmic-ray protons with gas, we calculate the neutrino flux predicted from each of these sources. Although this scenario is consistent with the constraints published by the IceCube and ANTARES Collaborations, the predicted fluxes consistently fall within an order of magnitude of the current point source sensitivity. The prospects appear very encouraging for the future detection of neutrino emission from the nearest radio galaxies.