Magnetic fields, winds and X-rays of the massive stars in the Orion Nebula Cluster

TL;DR

This study investigates how magnetic fields influence stellar winds and X-ray emissions in massive OB stars within the Orion Nebula Cluster, combining empirical spectropolarimetric observations with theoretical considerations.

Contribution

It provides the first empirical magnetic field measurements of OB stars in the Orion Nebula Cluster and examines their impact on stellar wind and X-ray emission properties.

Findings

Magnetic fields are detected in some OB stars.

Magnetic confinement affects stellar wind dynamics.

Correlations between magnetism and X-ray emission are explored.

Abstract

In some massive stars, magnetic fields are thought to confine the outflowing radiatively-driven wind. Although theoretical models and MHD simulations are able to illustrate the dynamics of such a magnetized wind, the impact of this wind-field interaction on the observable properties of a magnetic star - X-ray emission, photometric and spectral variability - is still unclear. The aim of this study is to examine the relationship between magnetism, stellar winds and X-ray emission of OB stars, by providing empirical observations and confronting theory. In conjunction with the COUP survey of the Orion Nebula Cluster, we carried out spectropolarimatric ESPaDOnS observations to determine the magnetic properties of massive OB stars of this cluster.