English
Related papers

Related papers: Test particle sampling and particle acceleration i…

200 papers

Understanding nonthermal particle generation, transport, and escape in solar flares requires detailed quantification of the particle evolution in the realistic 3D domain where the flare takes place. Rather surprisingly, apart of standard…

Solar and Stellar Astrophysics · Physics 2018-05-23 Gregory D. Fleishman , Gelu M. Nita , Natsuha Kuroda , Sabina Jia , Kevin Tong , Richard R. Wen , Zhou Zhizhuo

Particle acceleration in relativistic shocks of electron-positron plasmas with proton admixture is investigated through two-dimensional (2D) particle-in-cell (PIC) simulations. The upstream plasma, with a bulk Lorentz factor of $10$ and a…

High Energy Astrophysical Phenomena · Physics 2025-10-02 Huan Yu , Qi Xia , Jun Fang

The mechanism of diffusive Fermi acceleration at collisionless plasma shock waves is widely invoked in astrophysics to explain the appearance of non-thermal particle populations in a variety of environments, including sites of cosmic ray…

Astrophysics · Physics 2007-05-23 Matthew G. Baring

Microflares are energetically smaller versions of solar flares, demonstrating the same processes of plasma heating and particle acceleration. However, it remains unclear down to what energy scales this impulsive energy release continues,…

Solar and Stellar Astrophysics · Physics 2024-02-09 Kristopher Cooper , Iain G. Hannah , Lindsay Glesener , Brian W. Grefenstette

Observational aspects of solar flares relevant to the acceleration process of electrons and protons are reviewed and it is shown that most of these observations can be explained by the interaction with flare plasma of a power law energy…

Astrophysics · Physics 2007-05-23 Vahe Petrosian

With a test-particle simulation, we investigate the effect of large-scale coronal magnetic fields on electron acceleration at an outward-propagating coronal shock with a circular front. The coronal field is approximated by an analytical…

Solar and Stellar Astrophysics · Physics 2016-04-20 Xiangliang Kong , Yao Chen , Fan Guo , Shiwei Feng , Guohui Du , Gang Li

RHESSI measurements relevant to the fundamental processes of energy release and particle acceleration in flares are summarized. RHESSI's precise measurements of hard X-ray continuum spectra enable model-independent deconvolution to obtain…

Solar and Stellar Astrophysics · Physics 2011-10-11 R. P. Lin

Particles are accelerated to very high, non-thermal energies during explosive energy-release phenomena in space, solar, and astrophysical plasma environments. In the case of solar flares, it has been established that magnetic reconnection…

We carried out detailed analysis of X-ray and radio observations of a simple flare loop that occurred on 12th August 2002, with the impulsive hard X-ray (HXR) light curves dominated by a single pulse. The emission spectra of the early…

Solar and Stellar Astrophysics · Physics 2015-06-22 I. N. Sharykin , S. Liu , L. Fletcher

Magnetic fields and flows in coronal structures, for example, in gradual phases in flares, can be described by 2D and 3D magnetohydrostatic (MHS) and steady magnetohydrodynamic (MHD) equilibria. Within a physically simplified, but exact…

Solar and Stellar Astrophysics · Physics 2014-09-17 D. H. Nickeler , M. Karlicky , T. Wiegelmann , M. Kraus

Dispersive Alfven waves (DAWs) offer, an alternative to magnetic reconnection, opportunity to accelerate solar flare particles. We study the effect of DAW polarisation, L-, R-, circular and elliptical, in different regimes inertial and…

Solar and Stellar Astrophysics · Physics 2011-09-27 D. Tsiklauri

We use 2.5-D electromagnetic particle-in-cell simulation code to investigate the acceleration of electrons in solar coronal holes through the interaction of Alfv\'en waves with an interplume region. The interplume is modeled by a cavity…

Space Physics · Physics 2019-04-30 Khalil Daiffallah , Fabrice Mottez

Where and how flares efficiently accelerate charged particles remains an unresolved question. Recent studies revealed that a "magnetic bottle" structure, which forms near the bottom of a large-scale reconnection current sheet above the…

Solar and Stellar Astrophysics · Physics 2024-07-23 Bin Chen , Xiangliang Kong , Sijie Yu , Chengcai Shen , Xiaocan Li , Fan Guo , Yixian Zhang , Lindsay Glesener , Säm Krucker

We perform numerical simulations of particle acceleration in relativistic, self-driven turbulent magnetic reconnection using the MHD-PIC method. We systematically investigate the dependence of the non-thermal particle spectral exponent on…

High Energy Astrophysical Phenomena · Physics 2026-04-30 Shi-Min Liang , Jian-Fu Zhang , Nian-Yu Yi

The interrelation of hard X-ray (HXR) emitting sources and the underlying physics of electron acceleration and transport presents one of the major questions in high-energy solar flare physics. Spatially resolved observations of solar flares…

Solar and Stellar Astrophysics · Physics 2015-06-12 Paulo J. A. Simões , Eduard P. Kontar

The combination of isochoric heating of solids by free electron lasers (FEL) and in situ diagnostics by X-ray Thomson scattering (XRTS) allows for measurements of material properties at warm dense matter (WDM) conditions relevant for…

We propose the particle acceleration model coupled with multiple plasmoid ejections in a solar flare. Unsteady reconnection produces plasmoids in a current sheet and ejects them out to the fast shocks, where particles in a plasmoid are…

High Energy Astrophysical Phenomena · Physics 2015-06-12 N. Nishizuka , K. Shibata

This paper reviews the current state of our understanding of high-speed solar wind acceleration in coronal holes. Observations by SOHO, coupled with interplanetary particle measurements going back several decades, have put strong…

Astrophysics · Physics 2007-05-23 Steven R. Cranmer

Particle acceleration during magnetic reconnection is a long-standing topic in space, solar and astrophysical plasmas. Recent 3D particle-in-cell simulations of magnetic reconnection show that particles can leave flux ropes due to 3D…

Solar and Stellar Astrophysics · Physics 2022-07-20 Grant Johnson , Patrick Kilian , Fan Guo , Xiaocan Li

Finite thermal velocity modifications to electron slowing-down rates may be important for the deduction of solar flare total electron energy. Here we treat both slowing-down and velocity diffusion of electrons in the corona at flare…

Astrophysics · Physics 2009-11-11 Ross K. Galloway , Alexander L. MacKinnon , Eduard P. Kontar , Per Helander