Nishikawa, Ken-Ichi

Radiation from relativistic jets from particle accelerated by shocks, shear-flows, and reconnection.

Author list: K.-I. Nishikawa, P. Hardee, Y. Mizuno, I. Dutan, B. Zhang, M. Medvedev, E. J. Choi, K. W. Min, J. Niemiec, A. Nordlund, J. T. Frederiksen, H. Sol, M. Pohl, & D.H. Hartmann

We have investigated shock structure associated with an unmagnetized relativistic jet propagating into an unmagnetized plasma at the microscopic level. Strong magnetic fields are generated in the trailing (jet) shock along with electron acceleration. On small scales relativistic velocity shears between faster and slower moving material can also create strong DC magnetic fields via the kinetic Kelvin-Helmholtz instability (KKHI) and we have studied how the Lorentz factor affects the growth rate of KKHI. We have calculated, self-consistently, the radiation from electrons accelerated in turbulent shock magnetic fields and in the strong magnetic fields generated by KKHI. We find that synthetic spectra depend on the bulk Lorentz factor, the initial electron temperature, and the strength of the generated magnetic fields. The calculated radiation properties begin to provide an understanding of the complex time evolution and/or spectral structure from gamma-ray bursts, relativistic jets, and supernova remnants.