The Effect of Misalignment between the Rotation Axis and Magnetic Field on the Circumstellar Disk

The formation of circumstellar disks is investigated using three-dimensional resistive magnetohydrodynamic simulations in which the initial prestellar cloud has a misaligned rotation axis with respect to the magnetic field. We examine the effects of (i) the initial angle difference between the global magnetic field and the cloud rotation axis (θ₀) and (ii) the ratio of the thermal to gravitational energy (α₀). We study 16 models in total and calculate the cloud evolution until ∼5000 yr after protostar formation. Our simulation results indicate that an initial nonzero θ₀ (>0) promotes disk formation but tends to suppress outflow driving for models that are moderately gravitationally unstable, α₀ ≲ 1. In these models, a large-sized rotationally supported disk forms and a weak outflow appears, in contrast to a smaller disk and strong outflow in the aligned case (θ₀ = 0). Furthermore, we find that when the initial cloud is highly unstable with small α₀, the initial angle difference θ₀ does not significantly affect the disk formation and outflow driving.