Early Evolution of Disk, Outflow, and Magnetic Field of Young Stellar Objects: Impact of Dust Model

Abstract

The formation and early evolution of low-mass young stellar objects (YSOs) are investigated using three-dimensional non-ideal magnetohydrodynamics simulations. We investigate the evolution of YSOs up to after protostar formation, at which protostellar mass reaches . We particularly focus on the impact of the dust model on the evolution. We found that a circumstellar disk is formed in all simulations, regardless of the dust model. Disk size is approximately 10 au at the protostar formation epoch, and it increases to several tens of au at after protostar formation. The disk mass is comparable to the central protostellar mass, and gravitational instability develops. In simulations with small dust sizes, the warp of the pseudodisk develops after protostar formation. The warp strengthens magnetic braking in the disk and decreases disk size. Ion-neutral drift can occur in the infalling envelope when the typical dust size is and the protostar (plus disk) mass is . The outflow activity is anticorrelated to the dust size, and the strong outflow appears with small dust grains.