Strongly magnetised ion–electron Relativistic Reconnection with Guide Field

Relativistic magnetic reconnection is a fundamental mechanism of energy dissipation in magnetised astrophysical environments, including black hole coronae, pulsar winds, and relativistic jets. We present fully kinetic three-dimensional ion–electron simulations that extend recent studies of relativistic reconnection by scanning guide-field strength across strongly magnetised regimes. At low magnetisation, increasing guide field strength delays nonlinear disruption of the current sheet and strongly suppresses magnetic energy dissipation. The zero-guide-field case exhibits rapid collapse of the reconnecting field and efficient nonthermal electron acceleration, while strong guide fields stabilise the layer and significantly reduce high-energy tail formation. At higher magnetisations, reconnection remains rapid but the guide field regulates species energy partition between species. Stronger guide fields reduce the fraction of magnetic energy converted into nonthermal electrons and favour enhanced ion heating with softer electron spectra. These results demonstrate that the guide field strongly regulates three-dimensional plasma instability development, dissipation efficiency, and species-dependent particle acceleration in ion-electron plasmas.