  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 the 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.

High Energy Astrophysical Phenomena