Neutrino signal from gamma-ray loud binaries powered by high energy protons

TL;DR

This paper proposes a hadronic model for gamma-ray loud binaries, predicting high-energy neutrino fluxes that could be detected by IceCube, providing insights into particle acceleration near massive stars.

Contribution

It introduces a hadronic model linking neutrino fluxes to gamma-ray emissions in binaries, with specific predictions for IceCube detection capabilities.

Findings

Neutrino fluxes can be higher/harder than gamma-ray fluxes due to pp interactions.

IceCube can detect the source at 5 sigma after one year.

Three years of data can constrain neutrino spectral characteristics.

Abstract

We present a hadronic model of activity for Galactic gamma-ray-loud binaries, in which the multi-TeV neutrino flux from the source can be much higher and/or harder than the detected TeV gamma-ray flux. This is related to the fact that most neutrinos are produced in pp interactions close to the bright massive star, in a region optically thick for the TeV gamma-rays. Considering the specific example of LS I +61o 303, we derive upper bounds for neutrino fluxes from various proton injection spectra compatible with the observed multi-wavelength spectrum. At this upper level of neutrino emission, we demonstrate that ICECUBE will not only detect this source at 5 sigma C.L. after one year of operation, but, after 3 years of exposure, will also collect a sample marginally sufficient to constrain the spectral characteristics of the neutrino signal, directly related to the underlying source acceleration mechanisms.