Impact of rotation on the geometrical configurations of fossil magnetic fields

TL;DR

This paper investigates how stellar rotation influences the geometry of fossil magnetic fields in massive stars, revealing that rotation does not significantly alter their large-scale dipolar configurations.

Contribution

It extends previous models by incorporating rotation effects into the analysis of fossil magnetic field configurations in early-type stars.

Findings

Rotation has minimal impact on the dipolar geometry of fossil fields.

Fossil magnetic fields remain stable and large-scale regardless of stellar rotation rate.

Theoretical models now include rotation, aligning better with observations.

Abstract

The MiMeS project demonstrated that a small fraction of massive stars (around 7%) presents large-scale, stable, generally dipolar magnetic fields at their surface. They are supposed to be fossil remnants of initial phases of stellar evolution. In fact, they result from the relaxation to MHD equilibrium states during the formation of stable radiation zones of initial fields generated by a previous convective phase. In contrast with the case of magnetic fields built by dynamo mechanisms, the geometry of fossil fields at the surface of early-type stars seems to be independent of rotation: dipolar fields are observed both in slowly- and rapidly-rotating stars. In this work, we present new theoretical results, where we generalized previous studies by taking rotation into account. The properties of relaxed fossil fields are compared to those obtained when rotation is ignored. Consequences for magnetic fields in the radiative envelope of rotating early-type stars are discussed.