# Circumstellar disks and outflows in turbulent molecular cloud cores: possible formation mechanism for misaligned systems

## TL;DR

This study uses simulations to explore how magnetic fields and turbulence influence the formation, size, and alignment of circumstellar disks and outflows in turbulent molecular cloud cores, revealing mechanisms for misaligned systems.

## Contribution

It introduces detailed numerical simulations showing the impact of magnetic fields and turbulence on disk formation, size, and misalignment with outflows in star-forming regions.

## Key findings

- Magnetized disks are smaller than nonmagnetized ones but grow over time.
- Stronger magnetic fields lead to smaller disks.
- Disks tend to align with their angular momentum, but outflows can be misaligned due to magnetic and geometric effects.

## Abstract

We investigate the formation of circumstellar disks and outflows subsequent to the collapse of molecular cloud cores with the magnetic field and turbulence. Numerical simulations are performed by using an adaptive mesh refinement to follow the evolution up to $\sim 1000$~yr after the formation of a protostar. In the simulations, circumstellar disks are formed around the protostars; those in magnetized models are considerably smaller than those in nonmagnetized models, but their size increases with time. The models with stronger magnetic field tends to produce smaller disks. During evolution in the magnetized models, the mass ratios of a disk to a protostar is approximately constant at $\sim 1-10$\%. The circumstellar disks are aligned according to their angular momentum, and the outflows accelerate along the magnetic field on the $10-100$~au scale; this produces a disk that is misaligned with the outflow. The outflows are classified into two types: a magneto-centrifugal wind and a spiral flow. In the latter, because of the geometry, the axis of rotation is misaligned with the magnetic field. The magnetic field has an internal structure in the cloud cores, which also causes misalignment between the outflows and the magnetic field on the scale of the cloud core. The distribution of the angular momentum vectors in a core also has a non-monotonic internal structure. This should create a time-dependent accretion of angular momenta onto the circumstellar disk. Therefore, the circumstellar disks are expected to change their orientation as well as their sizes in the long-term evolutions.