相关论文: Microwave View on Particle Acceleration in Flares
Magnetic reconnection is an explosive energy release event. It plays an important role in accelerating particles to high non-thermal energies. These particles often exhibit energy spectra characterized by a power-law distribution. However,…
The acceleration and transport of energetic electrons during solar flares is one of the outstanding topics in solar physics. Recent X-ray and radio imaging and spectroscopy observations have provided diagnostics of the distribution of…
Magnetic reconnection has long been known to be the most important mechanism as quick conversion of magnetic field energy into plasma kinetic energy. In addition, energy dissipation by reconnection has gained attention not only as a plasma…
Acceleration of cosmic-ray electrons (CRe) in the intra-cluster-medium (ICM) is probed by radio observations that detect diffuse, Mpc-scale, synchrotron sources in a fraction of galaxy clusters. Giant radio halos are the most spectacular…
This paper presents a solely thermal flare, which we detected in the microwave range from the thermal gyro- and free-free emission it produced. An advantage of analyzing thermal gyro emission is its unique ability to precisely yield the…
Magnetic reconnection is a fundamental plasma process that is thought to play a key role in the production of nonthermal particles associated with explosive phenomena in space physics and astrophysics. Experiments at high-energy-density…
This review aims at providing an up-to-date status and a general introduction to the subject of the numerical study of energetic particle acceleration and transport in turbulent astrophysical flows. The subject is also complemented by a…
Observations of minute-scale flares in TeV Blazars place constraints on particle acceleration mechanisms in those objects. The implications for a variety of radiation mechanisms have been addressed in the literature; in this paper we…
Particle acceleration in collisionless astrophysical shocks, i.e., diffusive shock acceleration (DSA), is the most likely mechanism for producing cosmic rays, at least below 10^{15} eV. Despite the success of this theory, several key…
Counterpropagating Alfv\'en waves are ubiquitously observed in many astrophysical environments, such as a star surface and a planetary foreshock. We discuss an efficient particle acceleration mechanism in two counterpropagating circularly…
The problem of explaining observed soft X-ray fluxes during solar flares, which invokes acceleration of large fraction of electrons, if the acceleration takes places at the solar coronal loop-top, can potentially be solved by postulating…
We investigate the effects of pitch-angle scattering on the efficiency of particle heating and acceleration by MHD turbulence using phenomenological estimates and simulations of non-relativistic test particles interacting with strong,…
We use 2D particle-in-cell (PIC) simulations to study the effect of the saturated whistler instability on the viscous heating and nonthermal acceleration of electrons in a shearing, collisionless plasma with a growing magnetic field,…
We report the detection of emission from a non-thermal electron distribution in a small solar microflare (GOES class A5.7) observed by the Nuclear Spectroscopic Telescope Array (NuSTAR), with supporting observation by the Reuven Ramaty High…
Electron and ion energization (i.e., heating and nonthermal acceleration) is a fundamental, but poorly understood, outcome of plasma turbulence. In this work, we present new results on this topic from particle-in-cell simulations of driven…
We report studies on first-order Fermi acceleration in parallel modified shock waves with a large scattering center compression ratio expected from turbulence transmission models. Using a Monte Carlo technique we have modeled particle…
Extending previous studies of nonthermal electron transport in solar flares which include the effects of collisional energy diffusion and thermalization of fast electrons, we present an analytic method to infer more accurate estimates of…
Subcluster interactions within clusters of galaxies produce shocks that accelerate nonthermal particles. We treat Fermi acceleration of nonthermal electrons and protons by injecting power-law distributions of particles during the merger…
Relativistic magnetic turbulence has been proposed as a process for producing nonthermal particles in high-energy astrophysics. Particle energization may be contributed by both magnetic reconnection and turbulent fluctuations, but their…
We simulate decaying turbulence in a homogeneous pair plasma using three dimensional electromagnetic particle-in-cell (PIC) method. A uniform background magnetic field permeates the plasma such that the magnetic pressure is three times…