Synthetic radiation simulations as a path to study the relativistic Kelvin-Helmholtz instability in interstellar jets

The relativistic Kelvin-Helmholtz instability (KHI) is expected in shear flow regions of astrophysical plasma jets originating from AGNs and SNR. It generates magnetic fields that influence the jet dynamics significantly.

We present 3D3V particle-in-cell simulations of unprecedented resolution and extent that not only allow studying the plasma dynamics during the KHI but also making quantitative predictions on the emitted radiation. We present a diagnostic method that allows identifying the linear phase of the instability via a polarization anisotropy observable light years away on Earth and to quantify the growth rate of the instability.

A microscopic model, that describes the fundamental origin of the radiation signature, will be covered in detail during the talk. Technical aspects relevant for performing these large-scale simulations with the particle-in-cell code PIConGPU and for making quantitative predictions with synthetic radiation diagnostics, based on Liénard-Wiechert potentials, will be discussed, and observation limits both for interstellar jets and in lab astrophysics experiments will be covered.