Spectral studies of the Weibel turbulence via PIC simulations

Unmagnetized plasmas with (interpenetrating) plasma beams are highly unstable to electromagnetic instabilities such as the Weibel filamentation instability. High-energy-density plasmas in astrophysical systems are ubiquitous, and are present in collisionless shocks of gamma-ray bursts and supernova explosions, for instance. These are the locations where the beam-plasma Weibel instability naturally occurs. It affects plasma dynamics and observable electromagnetic radiation. Here we investigate collisionless, unmagnetized, counter-propagating plasmas with PIC simulations using TRISTAN-MP code. We developed a spectral analysis software suite which we now use at the post-processing stage. Here we present the time-dependent spectral analysis in the omega-k space and the angle-dependence of the plasma modes present in the system as it evolves in time. Various properties the excited plasma modes are discussed.