Related papers: Particle Acceleration by a Solar Flare Termination…
Solar Energetic Particles (SEPs) are an important component of Space Weather, including radiation hazard to humans and electronic equipment, and the ionisation of the Earth's atmosphere. We review the key observations of SEPs, our current…
Interplanetary Coronal Mass Ejection (ICME) shocks are known to accelerate particles and contribute significantly to Solar Energetic Particle (SEP) events. We have performed Magnetohydrodynamic-Particle in Cell (MHD-PIC) simulations of ICME…
Solar Energetic Particles (SEPs) and radio bursts are indicators of particle acceleration on the Sun and in the heliosphere. The accelerated particles have energies significantly higher than thermal particles up to several orders of…
Most theoretical investigations of particle acceleration during solar flares cannot be applied to observations for detailed study of the time evolution. We propose a phenomenological model for turbulence evolution and stochastic particle…
We propose a nonlinear self-consistent model of the turbulent non-resonant particle acceleration in solar flares. We simulate temporal evolution of the spectra of charged particles accelerated by strong long-wavelength MHD turbulence taking…
Flares are powerful energy releases occurring in stellar atmospheres. Solar flares, the most intense energy bursts in the solar system, are however hardly noticeable in the total solar luminosity. Consequently, the total amount of energy…
Observations relating the characteristics of electrons seen near Earth (SEPs) and those producing flare radiation show that in certain (prompt) events the origin of both population appears to be the flare site, which show strong correlation…
Diffusive shock acceleration (DSA), as an acceleration process for Galactic electrons at the solar wind termination shock (TS), is investigated with a comprehensive numerical model which incorporates shock-acceleration, particle drifts and…
Solar Energetic Particles (SEP) are an integral part of the physical processes related with Space Weather. We present a review for the acceleration mechanisms related to the explosive phenomena (flares and/or CMEs) inside the solar corona.…
The origin of radio emission from plerions is considered. Recent observations suggest that radio emitting electrons are presently accelerated rather than having been injected at early stages of the plerion evolution. The observed flat…
A number of double coronal X-ray sources have been observed during solar flares by RHESSI, where the two sources reside at different sides of the inferred reconnection site. However, where and how are these X-ray-emitting electrons…
We review basic theoretical concepts in particle acceleration, with particular emphasis on processes likely to occur in regions of magnetic reconnection. Several new developments are discussed, including detailed studies of reconnection in…
We study the solar energetic particle (SEP) event observed on 9 October 2021, by multiple spacecraft including Solar Orbiter (SolO). The event was associated with an M1.6 flare, a coronal mass ejection (CME) and a shock wave. During the…
We address the problem of how particles that are accelerated by solar flares can escape promptly into the heliosphere, on time scales of an hour or less. Impulsive solar energetic particles (SEP) bursts are generally observed in association…
X-ray observations are a direct diagnostic of fast electrons produced in solar flares, energized during the energy release process and directed towards the Sun. Since the properties of accelerated electrons can be substantially changed…
A popular scenario for electron acceleration in solar flares is transit-time damping of low-frequency MHD waves excited by reconnection and its outflows. The scenario requires several processes in sequence to yield energetic electrons of…
During solar flares a large amount of electrons are accelerated within the plasma present in the solar atmosphere. Accurate measurements of the motion of these electrons start becoming available from the analysis of hard X-ray…
Spatially-resolved X-ray observations are the key to understanding electron acceleration in solar flares. Currently, the underlying processes that efficiently energize solar flare particles are poorly constrained. Abundant flare…
Winds are ubiquitous in galaxies and often feature bubble structures. These wind bubbles are characterized by an external forward shock expanding in the surrounding medium and a wind termination shock separating the cool and fast wind from…
We propose a new two-stage model for acceleration of electrons in solar flares. In the first stage, electrons are accelerated stochastically in a post-reconnection turbulent downflow. The second stage is the reprocessing of a subset of…