The impact of non-ideal magnetohydrodynamic processes on discs, outflows, counter-rotation, and magnetic walls during the early stages of star formation

ABSTRACT Non-ideal magnetohydrodynamic (MHD) processes – namely Ohmic resistivity, ambipolar diffusion, and the Hall effect modify early stages of star formation process surrounding environment. Collectively, they have been shown to promote disc or hinder outflows. But which non-ideal has greatest impact? Using three-dimensional smoothed particle radiation MHD simulations, we model gravitational collapse a rotating, magnetized cloud through first hydrostatic core phase shortly after stellar core. We investigate impact each individually collectively. Including any decreases maximum magnetic field strength by at least an order magnitude during compared using ideal MHD, promotes wall. When rotation vectors are anti-aligned is included, rotationally supported discs r ? 20 au form; when only included aligned, counter-rotating pseudo-disc forms that not supported. Rotationally ? 4 form if resistivity diffusion included. The suppresses outflows independent alignment. delay launching Although influences formation, these results suggest influence.