相关论文: Statistical study of particle acceleration in the …

Foreshock transients upstream of Earth's bow shock have been recently observed to accelerate electrons to many times their thermal energy. How such acceleration occurs is unknown, however. Using THEMIS case studies, we examine a subset of…

Upstream of shocks, the foreshock is filled with hot ions. When these ions are concentrated and thermalized around a discontinuity, a diamagnetic cavity bounded by compressional boundaries, referred to as a foreshock transient, forms.…

Electron heating/acceleration in the foreshock, by which electrons may be energized beyond thermal energies prior to encountering the bow shock, is very important for the bow shock dynamics. And then these electrons would be more easily…

Magnetosheath jets are localized fast flows with enhanced dynamic pressure. When they supermagnetosonically compress the ambient magnetosheath plasma, a bow wave or shock can form ahead of them. Such a bow wave was recently observed to…

Foreshock disturbances -- large-scale (~1000 km to >30,000 km), transient (~5-10 per day - lasting ~10s of seconds to several minutes) structures [1,2] - generated by suprathermal (>100 eV to 100s of keV) ions [3,4] arise upstream of…

In situ observations of energetic particles at the Earth's bow-shock that are attainable by the satellite missions have long created the opinion that electrons are most efficiently accelerated in a quasi-perpendicular shock geometry.…

Thermalization and heating of plasma flows at shocks result in unstable charged-particle distributions which generate a wide range of electromagnetic waves. These waves, in turn, can further accelerate and scatter energetic particles. Thus,…

Foreshock transients are ion kinetic structures in the ion foreshock. Due to their dynamic pressure perturbations, they can disturb the bow shock and magnetosphere-ionosphere system. They can also accelerate particles contributing to shock…

We characterize the nature of magnetic structures in the foreshock region of Mars associated with discontinuities in the solar wind. The structures form at the upstream edge of moving foreshocks caused by slow rotations in the…

Charged particles can be accelerated to high energies by collisionless shock waves in astrophysical environments, such as supernova remnants. By interacting with the magnetized ambient medium, these shocks can transfer energy to particles.…

Foreshock transients upstream of the Earth's bow shock, such as foreshock bubbles and hot flow anomalies, are often characterized by reduced-density cores and strong plasma fluctuations. These conditions provide environments where…

We present measurements from the ESA/NASA Cluster mission that show in situ acceleration of ions to energies of 1 MeV outside the bow shock. The observed heating can be associated with the presence of electromagnetic structures with strong…

We present a study of the acceleration of electrons at a perpendicular shock that propagates through a turbulent magnetic field. The energization process of electrons is investigated by utilizing a combination of hybrid (kinetic ions and…

The main signature of the interaction between cosmic rays and molecular clouds is the high ionisation degree. This decreases towards the densest parts of a cloud, where star formation is expected, because of energy losses and magnetic…

Context: Acceleration in coronal mass ejection driven shocks is currently considered the primary source of large solar energetic particle events. Aims: The solar wind, which feeds shock-accelerated particles, includes numerous ion…

We use the multi-spacecraft capabilities of the Cluster and THEMIS missions to show that two types of foreshock may be detected in spacecraft data. One is the global foreshock that appears upstream of the Earth's quasi-parallel bow-shock…

Collisionless shocks are efficient particle accelerators. At Earth, ions with energies exceeding 100 keV are seen upstream of the bow shock when the magnetic geometry is quasi-parallel, and large-scale supernova remnant shocks can…

The formation of collisionless shock fronts is an ubiquitous phenomenon in space plasma environments. In the solar wind shocks might accompany coronal mass ejections, while even more violent events, such as supernovae, produce shock fronts…

When a magnetosheath jet (localized dynamic pressure enhancements) compresses ambient magnetosheath at a (relative) speed faster than the local magnetosonic speed, a bow wave or shock can form ahead of the jet. Such bow waves or shocks were…

The effect of compressibility in charged particle energization by magnetohydrodynamic (MHD) fields is studiedin the context of test particle simulations. This problem is relevant to the solar wind and the solar corona due to the…