Investigating Relativistic Jets: Particle-in-Cell Simulations and Synthetic Spectra with Toroidal Magnetic Field Effects

We present the first self-consistently calculated spectra from electrons accelerated in relativistic jets containing an initial, toroidal magnetic field, where the jets are being injected into an ambient plasma at rest. We use three-dimensional, relativistic particle-in-cell calculations for different setups of plasma species, strengths of the initial magnetic field, Lorentz factor of the jet, and emission angles. Our results show the basic properties of jitter-like spectra, where the low frequency slope of the spectrum is steeper than the 1/3 slope of synchrotron radiation. Our calculations can be relevant for explaining the observed spectra from gamma-ray bursts.