Non-gyrotropic ions as evidence for an X-type neutral region Original Research Article

Based on modern satellite observations in the earthʹs magnetotail and advanced computer simulation studies, it becomes possible to discuss demonstratively a kinetic magnetic reconnection process beyond ion inertia scale. One of the important findings is the observation of non-Maxwellian/non-gyrotropic ion distribution functions in the magnetotail. We discuss that a specific kind of non-gyrotropic ion distribution can be observed in the vicinity of an X-type neutral region.