A coupled guiding center-Boris particle pusher for magnetized plasmas in compact-object magnetospheres

Understand

We present a novel numerical scheme for simulating the motion of relativistic charged particles in magnetospheres of compact objects, typically filled with highly magnetized collisionless plasmas.

• The new algorithm is based on a dynamic switch between the full system of equations of motion and a guiding center approximation.
• The switch between the two formulations is based on the magnetization of the plasma particles, such that the dynamics are accurately captured by the guiding center motion even when the gyro-frequency is under-resolved by the time step.
• For particles with a large gyro-radius, due to acceleration in, e.g., reconnecting current sheets, the algorithm adaptively switches to solve the full equations of motion instead.