Spatial Distributions of Energetic Electrons and Energetic Ions in the Tail Reconnection Region: Cluster Observations and PIC Simulations

Abstract High‐energy particles are prevalent in space, and magnetic reconnection is one of the physical processes responsible for their generation. The heating and acceleration of ions and electrons typically occur respectively in the ion diffusion region and the electron diffusion region. In addition, the reconnection front is also a region for particle heating and acceleration. However, the spatial distribution of energetic particles in the reconnection region is less understood. In this work, we present in situ observations by the Cluster spacecraft that capture the spatial distributions of energetic ions and electrons in the magnetotail reconnection region. Our results show that high‐energy electrons are preferably observed around the separatrix region, while high‐energy ions are observed throughout the outflow region. To verify this spatial difference, we also conduct fully kinetic particle‐in‐cell (PIC) simulations, which correspond well with the observations. Our results improve the understanding of the generation and the spatial distribution of high‐energy particles in space.