THREE-DIMENSIONAL RELATIVISTIC MAGNETOHYDRODYNAMIC SIMULATIONS OF CURRENT-DRIVEN INSTABILITY. III. ROTATING RELATIVISTIC JETS

Abstract

We have investigated the influence of jet rotation and differential motion on\nthe linear and nonlinear development of the current-driven (CD) kink\ninstability of force-free helical magnetic equilibria via three-dimensional\nrelativistic magnetohydrodynamic simulations. In this study, we follow the\ntemporal development within a periodic computational box. Displacement of the\ninitial helical magnetic field leads to the growth of the CD kink instability.\nWe find that, in accord with linear stability theory, the development of the\ninstability depends on the lateral distribution of the poloidal magnetic field.\nIf the poloidal field significantly decreases outwards from the axis, the\ninitial small perturbations grow strongly, and if multiple wavelengths are\nexcited non-linear interaction eventually disrupts the initial cylindrical\nconfiguration. When the profile of the poloidal field is shallow, the\ninstability develops slowly and eventually saturates. We briefly discuss\nimplications of our findings for Poynting dominated jets.\n