Princeton University Astroplasmas Seminar

Pulsars are rapidly rotating neutron stars immersed in strong electromagnetic fields that emit twin beams of electromagnetic radiation. However, the plasma composition and structure in the region surrounding pulsars, called magnetospheres, and the physical processes that drive particle acceleration leading to the observed spectra are not well understood. Global pulsar magnetosphere simulations are required to answer these questions. However, resolving the current sheet skin-depth which is six orders of magnitude smaller than the pulsar radius for realistic systems, is intractable even on large supercomputers. In this talk, I present a two-pronged approach to study particle acceleration. First, we use a “wide computational lens” to perform global pulsar simulations with scaled-down energies. I will present the effect of magnetization on the plasma structure in the magnetosphere and particle energization. Second, we use a “focussed lens” to study relativistic reconnection in the currents sheets using a Harris-sheet set-up. For the reconnection simulations, we will also explore the use of ultra high-order spectral methods (PSATD) and compare its accuracy and efficiency with traditional Yee methods. For our simulations, we use WarpX, a highly scalable, electromagnetic PIC code with advanced algorithms to simulate relativistic plasma on large-scale heterogeneous supercomputers.