A lepto-hadronic model for high-energy emission from FR I radiogalaxies

TL;DR

This paper presents a lepto-hadronic model explaining high-energy gamma-ray emission from FR I radiogalaxies' jets, accounting for multi-wavelength radiation, secondary particles, and neutrino signals, aligning with recent observations of sources like Cen A and M87.

Contribution

It introduces a comprehensive lepto-hadronic model for VHE emission in FR I radiogalaxies, including particle acceleration, cooling, transport, and secondary particle contributions, with potential neutrino detection predictions.

Findings

Model reproduces observed spectra of Cen A and M87.

Predicts detectable high-energy neutrino fluxes with IceCube and KM3Net.

Accounts for multi-wavelength emission and secondary particle contributions.

Abstract

The well know radiogalaxy Cen A has been recently detected as a source of very high energy (VHE) gamma-rays by the HESS experiment just before Fermi/LAT detected it at high energies (HE). The detection, together with that of M87, establishes radiogalaxies as VHE gamma-ray emitters. The aim of this work is to present a lepto-hadronic model for the VHE emission from the relativistic jets in FR I radiogalaxies. We consider that protons and electrons are accelerated in a compact region near the base of the jet, and they cool emitting multi wavelength radiation as they propagate along the jet. The proton and electron distributions are obtained through an inhomogeneous steady-state transport equation taking into account acceleration, radiative and non-radiative cooling processes, as well as particle transport by convection. Considering the effects of photon absorption at different wavelengths, we calculate the radiation emitted by the primary protons and electrons, as well as the contribution of secondaries particles (e+/-, pions and muons). The expected high-energy neutrino signal is also obtained and the possibility of detections with KM3Net and IceCube is discussed. The spectral energy distribution obtained in our model with an appropriate set of parameters for an extended emission zone can account for much of the observed spectrum for both AGNs.