A self-consistent leptonic–hadronic interpretation of the electromagnetic and neutrino emissions from blazar TXS 0506+056

The potential association between the blazar TXS 0506+056 and the neutrino event IceCube-170922A provides a unique opportunity to study the possible physical connection between high-energy photons and neutrinos. We explore the correlated electromagnetic and neutrino emissions of blazar TXS 0506+056 by a self-consistent leptonic–hadronic model, taking into account particle stochastic acceleration and all relevant radiative processes self-consistently. The electromagnetic and neutrino spectra of blazar TXS 0506+056 are reproduced by the proton synchrotron and hybrid leptonic–hadronic models based on the proton–photon interactions. It is found that the hybrid leptonic–hadronic model can be used to better explain the observed X-ray and $\gamma$-ray spectra of blazar TXS 0506+056 than the proton synchrotron model. Moreover, the predicted neutrino spectrum of the hybrid leptonic–hadronic model is closer to the observed one compared to the proton synchrotron model. We suggest that the hybrid leptonic–hadronic model is more favored if the neutrino event IceCube-170922A is associated with the blazar TXS 0506+056.