The Challenge of Sub-Keplerian Rotation for Disk Winds

TL;DR

This paper discusses how strong magnetic fields in disks around young stars cause sub-Keplerian rotation, complicating the thermal launching of disk winds unless gas diffusion is rapid, highlighting a key challenge in disk-wind theory.

Contribution

It identifies a critical challenge in disk-wind theory caused by sub-Keplerian rotation due to strong magnetization, emphasizing the role of gas diffusion rates.

Findings

Sub-Keplerian rotation impedes thermal disk wind launching.

Fast gas diffusion across magnetic field lines is necessary.

Magnetization levels significantly influence wind launching mechanisms.

Abstract

Strong magnetization makes the disks surrounding young stellar objects rotate at rates that are too sub-Keplerian to enable the thermal launching of disk winds from their surfaces unless the rate of gas diffusion across field lines is dynamically fast. This under-appreciated implication of disk magnetization poses a considerable challenge for disk-wind theory.