Electromagnetic draping of merging neutron stars

TL;DR

This paper derives equations for stationary relativistic force-free plasma configurations and shows that electromagnetic draping during neutron star mergers causes inevitable dissipation and jet formation, impacting observable emissions.

Contribution

It introduces a general framework for stationary force-free plasma without symmetry assumptions and demonstrates electromagnetic draping's role in dissipation during neutron star mergers.

Findings

Electromagnetic draping causes dissipation near neutron stars.

Relativistic jets are expected even in single-magnetized mergers.

Dissipative regions form at magnetospheric boundaries.

Abstract

We first derive a set of equations describing general stationary configurations of relativistic force-free plasma, without assuming any geometric symmetries. We then demonstrate that electromagnetic interaction of merging neutron stars is necessarily dissipative due to the effect of electromagnetic draping - creation of dissipative regions near the star (in the single-magnetized case) or at the magnetospheric boundary (in the double-magnetized case). Our results indicate that even in the single magnetized case we expect that relativistic jets (or ``tongues'') are produced, with correspondingly beamed emission pattern.