Radiative Magnetic Reconnection in Strong Magnetic Fields in Neutron Star Magnetospheres: an Overview

Relativistic collective plasma processes taking place in the presence of very strong magnetic fields play an important role in many high-energy astrophysical systems, most notably, in the magnetospheres of neutron stars (NSs), including radio-pulsars and magnetars. An important example of such processes is magnetic reconnection, which leads to a powerful and rapid release of magnetic energy and its conversion to plasma heating, nonthermal particle acceleration, and, ultimately, radiation, often powering intense X-ray and gamma-ray flares. In contrast to the more familiar examples of reconnection in the Earth’s magnetosphere and the solar corona, the strong magnetic field in NS magnetospheres causes the energized relativistic particles to emit synchrotron radiation and thus suffer radiation-reaction losses. Moreover, at highest field strengths, approaching the critical quantum (Schwinger) field, QED effects, including pair production, come into play. The reconnecting field strength controls the physical regime of magnetic reconnection in such environments, as well as its observational signatures. In this talk I will give a comprehensive overview of the resulting hierarchy of radiative/QED physical regimes of relativistic reconnection across a broad range of astrophysical NS scenarios. I will also discuss the prospects for future experimental exploration of these reconnection regimes using powerful next-generation lasers.