2022ApJ...929...42K

We have investigated electromagnetic (EM) wave pulses in a jet from a neutrino-driven accretion flow (NDAF) around a black hole (BH). NDAFs are massive accretion disks whose accretion rates are {dot}M ~0.01-10 M_☉ s^–1 for stellar-mass BHs. Such an extreme accretion may produce a collimated relativistic outflow like a magnetically driven jet in active galactic nuclei and microquasars. When we consider strong toroidal magnetic field stranded in the inner region of an NDAF disk and magnetic impulses on the jet, we find that they lead to the emanation of high-energy emissions for gamma-ray bursts, as well as high-energy cosmic rays. When Alfvenic wave pulses are generated by episodic immense accretions, they propagate along the large-scale structured magnetic field in the jet. Once the Alfvenic wave pulses reach nearly the speed of light in the underdense condition, they turn into EM wave pulses, which produce plasma wakes behind them. These wakefields exert a collective accelerating force synchronous to the motion of particles. As a result, the wakefield acceleration premises various observational signatures, such as pulsating bursts of high-energy gamma rays from accelerated electrons, pulses of neutrinos from accelerated protons, and protons with maximum energies beyond 10²⁰ eV.