Global simulations of relativistic jets with shocks and shear-flow

We investigated particle acceleration and shock structure associated with an unmagnetized relativistic jet propagating into an unmagnetized plasma. Strong magnetic fields generated in the trailing shock contribute to the electron’s transverse deflection and acceleration. Kinetic Kelvin-Helmholtz instability (kKHI) is also responsible to create strong DC and AC magnetic fields. The velocity shears in core-sheath jets create strong magnetic field perpendicular to the jet. The simulations where unmagnetized jets are injected into unmagnetized ambient plasmas show an excitation of the Weibel instability with kKHI and particle acceleration and its ejection from the jets. We examine how the Lorentz factors of jets affect the growth rates of kKHI. We have calculated, self-consistently, the radiation from electrons accelerated in these turbulent magnetic fields in the shocks. We found that the synthetic spectra depend on the bulk Lorentz factor of the jet, its temperature and strength of the generated magnetic fields. We will investigate synthetic spectra from accelerated electrons in strong magnetic fields generated by the combined effects of shock and kKHI injecting relativistic jets in ambient plasmas. The calculated properties of the emerging radiation provide our understanding of the complex time evolution and/or spectral structure in gamma-ray bursts, relativistic jets in general, and supernova remnants.