Winds of Massive Magnetic Stars: Interacting Fields and Flow

TL;DR

This study uses 3D MHD simulations to explore how magnetic fields influence stellar wind structures and their observable radio emissions in massive stars, revealing complex, warped disk formations caused by magnetic and rotational interactions.

Contribution

It provides the first detailed 3D simulations of magnetically confined stellar winds with inclined magnetic axes, linking magnetic topology to observable radio variability.

Findings

Magnetic confinement leads to warped disk structures.

Radio emission variability correlates with magnetic and rotational geometry.

Simulations predict observable signatures in radio light curves.

Abstract

We present results of 3D numerical simulations of magnetically confined, radiatively driven stellar winds of massive stars, conducted using the astrophysical MHD code Pluto, with a focus on understanding the rotational variability of radio and sub-mm emission. Radiative driving is implemented according to the Castor, Abbott and Klein theory of radiatively driven winds. Many magnetic massive stars posses a magnetic axis which is inclined with respect to the rotational axis. This misalignment leads to a complex wind structure as magnetic confinement, centrifugal acceleration and radiative driving act to channel the circumstellar plasma into a warped disk whose observable properties should be apparent in multiple wavelengths. This structure is analysed to calculate free-free thermal radio emission and determine the characteristic intensity maps and radio light curves.