Two-Fluid MHD Simulation of Relativistic Magnetic Reconnection

Magnetic reconnection is a driver of explosive events in space- and astrophysical plasmas. It also plays a role in high-energy astrophysical settings such as pulsar winds and magnetar flares, where plasmas are composed of relativistic electrons and positrons. Kinetic-scale properties of relativistic magnetic reconnection in these environments have been recently investigated by PIC simulations. In addition, a good relativistic MHD model is needed in order to model further large-scale problems. However, due to the extreme complexity of the equation system, the number of MHD studies has been quite limited. We have recently developed a relativistic multi-fluid code to study large-scale reconnection problems. We consider a symmetric two-fluid system (positron fluid and electron fluid) and introduce an inter-species friction term to represent an effective resistivity. With a spatially localized resistivity profile, we successfully simulated magnetic reconnection in a relativistic two-fluid system. In this paper we will present the nonlinear, large- scale, long-term evolutions, and parameter dependencies (e.g. reconnection rate vs inflow energy composition) of the relativistic MHD reconnection system.