Describing correlated observations of neutrino and gamma ray flares from the blazar TXS 0506+056 with proton blazar model

TL;DR

This paper proposes a proton blazar model where non-relativistic protons enable proton-proton interactions, explaining the observed neutrino and gamma-ray emissions from the blazar TXS 0506+056 without requiring external photon fields or high-density clouds.

Contribution

It introduces a proton blazar model based on non-relativistic protons for neutrino and gamma-ray production, challenging previous reliance on external photons or dense clouds.

Findings

Proton-proton interactions can account for observed neutrino and gamma-ray signals.

External photon fields are not necessary for high-energy neutrino production.

The model aligns with the lack of broadline emission in TXS 0506+056.

Abstract

Recent detection of the neutrino event, IceCube-170922A by IceCube observatory from the Blazar TXS 0506+056 in the state of enhanced gamma ray emission indicates for acceleration of cosmic rays in the blazar jet. The non-detection of the broadline emission in the optical spectrum of TXS 0506+056 and other BL Lac objects suggests that external photons emissions are weak and hence photo-meson (p-gamma) interaction may not be a favored mechanism for high energy neutrino production. The lack of broadline signatures also creates doubt about the presence of a high density cloud in the vicinity of the super-massive black hole (SMBH) of TXS 0506+056 and consequently raised question on hadronuclear (pp) interaction interpretation like relativistic jet meets with high density cloud. Here we demonstrate that non-relativistic protons in the proton blazar model, those come into existence under charge neutrality condition of the blazar jet, offer sufficient target matter for pp-interaction with shock accelerated protons and consequently the model can describe consistently the observed high energy gamma rays and neutrino signal from the blazar TXS 0506+056.