The Biermann battery driven by a streaming plasma

TL;DR

This paper introduces a novel mechanism for magnetic field generation via the Biermann battery driven by streaming plasma, supported by three-fluid simulations showing seed magnetic fields at high redshift.

Contribution

It proposes a new Biermann battery mechanism involving inhomogeneous plasma with a beam component, expanding understanding of cosmic magnetic field origins.

Findings

Magnetic fields can be generated by this mechanism at redshift ~20.

The process involves electron pressure gradients not aligned with density gradients.

Simulations confirm the viability of the proposed magnetic field generation.

Abstract

The Biermann battery is a promising generation mechanism of a seed magnetic field in the universe. We propose a new driving mechanism for the Biermann battery in an inhomogeneous plasma with a beam component. An inhomogeneous electron flow induced by the return current can make an electron pressure gradient which is not parallel to the density gradient. As a result, the magnetic field is generated by the Biermann battery. We demonstrate the new generation mechanism of the magnetic field by conducting three-fluid plasma simulations. By this mechanism, the first cosmic rays can generate the seed magnetic field with astrophysical scales at redshift around 20.