Early evolution of disk, outflow, and magnetic field of young stellar objects: Impact of dust model

TL;DR

This study uses 3D non-ideal MHD simulations to explore how dust models influence the early evolution of disks, outflows, and magnetic fields in young stellar objects within the first 10,000 years.

Contribution

It demonstrates that dust size significantly affects disk formation, magnetic braking, and outflow activity during the early stages of YSO evolution.

Findings

Disks form in all simulations, growing to tens of AU within 10^4 years.

Small dust sizes lead to warped pseudodisks and stronger magnetic braking.

Outflow activity is stronger with smaller dust grains.

Abstract

The formation and early evolution of low mass young stellar objects (YSOs) are investigated using three-dimensional non-ideal magneto-hydrodynamics simulations. We investigate the evolution of YSOs up to ~ 10^4 yr after protostar formation, at which protostellar mass reaches ~ 0.1 M_\odot . 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 ~ 10^4 yr after protostar formation. Disk mass is comparable to central protostellar mass and gravitational instability develops. In the simulations with small dust size, the warp of the pseudodisk develops ~ 10^4 yr after protostar formation. The warp strengthens magnetic braking in the disk and decreases disk size. Ion-neutral drift can occur in the infalling envelope under the conditions that the typical dust size is a \gtrsim 0.2{\mu}m and the protostar (plus disk) mass is M \gtrsim 0.1 M_\odot. The outflow activity is anti-correlated to the dust size and the strong outflow appears with small dust grains.