Very high energy neutrino expectation from Fanaroff-Riley I sources

TL;DR

This paper investigates the potential for high-energy neutrino emission from Fanaroff-Riley I radio galaxies, specifically Centaurus A and M87, by modeling hadronic processes to explain their TeV gamma-ray fluxes and predicting neutrino event rates.

Contribution

It introduces hadronic models to explain TeV gamma-ray emissions from Centaurus A and M87 and predicts associated neutrino fluxes and detection prospects.

Findings

Hadronic models can account for the observed TeV gamma-ray spectra.

Predicted neutrino event rates are compared with IceCube observations.

Neutrino fluxes depend on the specific TeV emission scenarios considered.

Abstract

Fanaroff-Riley I radiogalaxies have been observed in TeV gamma-rays during the last decades. The origin of the emission processes related with this energy band is still under debate. Here we consider the case of the two closest Fanaroff-Riley I objects: Centaurus A and M87. Their entire broadband spectral energy distributions and variability fluxes show evidences that leptonic models are not sufficient to explain their fluxes above 100 GeV. Indeed, both objects have been imaged by LAT instrument aboard of Fermi telescope with measured spectra well connected with one-zone leptonic models. However, to explain the TeV spectra obtained with campaigns by H.E.S.S., for Centaurus A, and by VERITAS, MAGIC and H.E.S.S. for M87, different emission processes must be introduced. In this work we evoke hadronic scenarios to describe the TeV gamma-ray fluxes observed and to obtain the expected neutrino counterparts for each considered TeV campaign. With the obtained neutrino spectra we calculate, through Monte Carlo simulations, the expected neutrino event rate in a hypothetical Km$^{3}$ neutrino telescope and we compare the results with what has been observed by IceCube experiment up to now.