Kink Instability: Evolution and Energy Dissipation in Relativistic Force-free Nonrotating Jets

Abstract

Abstract We study the evolution of kink instability in a force-free, nonrotating plasma column of high magnetization. The main dissipation mechanism is identified as reconnection of magnetic field lines with various intersection angles, driven by the compression of the growing kink lobes. We measure dissipation rates dU Bϕ /dt ≈ −0.1U Bϕ /τ, where τ is the linear growth time of the kink instability. This value is consistent with the expansion velocity of the kink mode, which drives the reconnection. The relaxed state is close to a force-free Taylor state. We constrain the energy of that state using considerations from linear stability analysis. Our results are important for understanding magnetic field dissipation in various extreme astrophysical objects, most notably in relativistic jets. We outline the evolution of the kink instability in such jets and derive constraints on the conditions that allow for the kink instability to grow in these systems.