The Stellar-Disk Electric (Short) Circuit: Observational Predictions for a YSO Jet Flow

TL;DR

This paper explores how a short circuit in the star-disk electric circuit of a young stellar object can generate magnetically-driven bipolar jets, with specific predictions on jet speeds and mass loss rates.

Contribution

It introduces a model linking star-disk electric circuit short circuits to jet formation, providing observational predictions for jet properties in YSOs.

Findings

Short circuit can produce bipolar jets perpendicular to the disk.

Jet speeds can reach hundreds of km/s.

Mass loss rate depends on accretion rate and disk radius.

Abstract

We discuss the star-disk electric circuit for a young stellar object (YSO) and calculate the expected torques on the star and the disk. We obtain the same disk magnetic field and star-disk torques as given by standard magnetohydrodynamic (MHD) analysis. We show how a short circuit in the star-disk electric circuit may produce a magnetically-driven jet flow from the inner edge of a disk surrounding a young star. An unsteady bipolar jet flow is produced that flows perpendicular to the disk plane. Jet speeds of order hundreds of kilometres per second are possible, while the outflow mass loss rate is proportional to the mass accretion rate and is a function of the disk inner radius relative to the disk co-rotation radius.