Magnetic Fields and Particle Energization in High-Energy Astrophysics and Space Physics

It is well established and tested that astrophysical plasmas and plasmas in space are permeated by magnetic fields. Many high-energy astrophysical systems, e.g. gamma-ray bursts, pulsar winds, accretion disks/jets, are strongly magnetized and are huge reservoirs of magnetic energy. Magnetic fields also play important roles in solar flares and particle propagation in the heliosphere. Understanding the fundamental physical processes, including the efficient dissipation of magnetic energy, acceleration/heating, diffusion, and cooling of particles, is important for studying a variety of astrophysical phenomena and solar phenomena and explaining multi-band/messenger observations. The synergy of recent theoretical/numerical developments and broadband observations on the physical processes involving magnetic fields and energized particles and associated phenomena is advantageous.

Studying the magnetic fields and particle energization in diverse systems in astrophysical and space plasmas requires a good understanding of the fundamental physical processes over a broad range of length scales and particle energies. This has been a great challenge for both theoretical and numerical studies. Recent advances in numerical simulations with, e.g. particle-in-cell (PIC) method, magnetohydrodynamic (MHD) method, combined PIC-MHD method, and their applications to studying both microscopic plasma physics and macroscopic astrophysical physics in realistic astrophysical settings have significantly improved our understanding of many long-standing problems and have successfully explained observations.

Basic plasma physical processes, e.g. magnetic reconnection, reconnection acceleration, can have very different behaviors and efficiencies in different physical conditions. The applicability of microscopic plasma physics to large-scale astrophysical systems with extreme physical conditions (e.g. strong magnetization) should be addressed and tested with different numerical methods. This investigation would have important implications for studying a wide range of problems in astrophysics and space physics, which share many common features in observations.

The scope of this Research Topic includes theoretical, numerical, and observational studies on magnetic fields and particle energization in high-energy astrophysical / space environments. We are interested in both Reviews of recent advances in the field and articles reporting new findings.

Specific themes of interest include:
1) Magnetic reconnection in high-energy astrophysical / space environments;
2) Particle acceleration mechanisms in high-energy astrophysical / space environments;
3) Other physical processes closely related to magnetic fields and particle energization in high-energy astrophysical / space environments;
4) Observational techniques for probing, e.g. magnetic fields, and constraining theoretical models in high-energy astrophysical / space environments.