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Related papers: Particle Acceleration by Fast Modes in Solar Flare…

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Magnetic energy released in the corona by solar flares reaches the chromosphere where it drives characteristic upflows and downflows known as evaporation and condensation. These flows are studied here for the case where energy is…

Solar and Stellar Astrophysics · Physics 2015-06-22 D. W. Longcope

We analyze electron flux maps based on RHESSI hard X-ray imaging spectroscopy data for a number of extended coronal loop flare events. For each event, we determine the variation of the characteristic loop length $L$ with electron energy…

Solar and Stellar Astrophysics · Physics 2015-06-15 Jingnan Guo , A. Gordon Emslie , Michele Piana

We expand the off-resonant scattering theory for particle diffusion in magnetized current filaments that can be typically compared to astrophysical jets, including active galactic nucleus jets. In a high plasma beta region where the…

Astrophysics · Physics 2009-11-13 Mitsuru Honda , Yasuko S. Honda

Solar energetic particles acceleration by a shock wave accompanying a coronal mass ejection (CME) is studied. The description of the accelerated particle spectrum evolution is based on the numerical calculation of the diffusive transport…

High Energy Astrophysical Phenomena · Physics 2017-02-09 A. S. Petukhova , I. S. Petukhov , S. I. Petukhov , L. T. Ksenofontov

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…

Space Physics · Physics 2015-06-05 Fan Guo , Joe Giacalone

In this chapter, we review some features of particle acceleration in astrophysical jets. We begin by describing four observational results relating to the topic, with particular emphasis on jets in active galactic nuclei and parallels…

High Energy Astrophysical Phenomena · Physics 2020-11-11 James Matthews , Anthony Bell , Katherine Blundell

We analyze measured proton and electron temperatures in the high-speed solar wind in order to calculate the separate rates of heat deposition for protons and electrons. When comparing with other regions of the heliosphere, the fast solar…

Solar and Stellar Astrophysics · Physics 2015-05-13 Steven R. Cranmer , William H. Matthaeus , Benjamin A. Breech , Justin C. Kasper

Evaporation of chromospheric plasma by particle beams has been a standard feature of models of solar flares for many decades, supported both by observations of strong hard X-ray bremsstrahlung signals, and detailed 1D hydrodynamic radiative…

Solar and Stellar Astrophysics · Physics 2023-10-18 Malcolm Keith Druett , Wenzhi Ruan , Rony Keppens

Context. It has been suggested that collapsing magnetic traps may contribute to accelerating particles to high energies during solar flares. Aims. We present a detailed investigation of the energization processes of particles in collapsing…

Solar and Stellar Astrophysics · Physics 2012-09-05 K. J. Grady , T. Neukirch , P. Giuliani

We determine the spectrum of particles accelerated at shocks with arbitrary speed and arbitrary scattering properties for different choices of the equation of state of the downstream plasma. More specifically we consider the effect of…

Astrophysics · Physics 2009-11-13 G. Morlino , P. Blasi , M. Vietri

We consider the acceleration of charged particles in relativistic shearing flows, with Lorentz factor up to $\Gamma_0 \sim 20$. We present numerical solutions to the particle transport equation and compare these with results from analytical…

High Energy Astrophysical Phenomena · Physics 2022-07-20 Frank M. Rieger , Peter Duffy

Gradual shear acceleration of energetic particles in gamma-ray burst (GRB) jets is considered. Special emphasis is given to the analysis of universal structured jets, and characteristic acceleration timescales are determined for a power-law…

Astrophysics · Physics 2009-11-13 Frank M. Rieger , Peter Duffy

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

The first self-consistent simulations of electron acceleration during magnetic reconnection in a macroscale system are presented. Consistent with solar flare observations the spectra of energetic electrons take the form of power-laws that…

A new mechanism for acceleration and enrichment of 3He during impulsive solar flares is presented. Low-frequency electromagnetic plasma waves excited by the Electron Firehose Instability (EFI) can account for the acceleration of ions up to…

Astrophysics · Physics 2009-11-07 G. Paesold , R. Kallenbach , A. O. Benz

The subject of this paper is stochastic acceleration by plasma turbulence, a process akin to the original model proposed by Fermi. We review the relative merits of different acceleration models, in particular the so called first order Fermi…

High Energy Astrophysical Phenomena · Physics 2015-06-05 Vahe Petrosian

The recent discovery of PeV electrons from the Crab nebula, produced on rapid time scales of one day or less with a sharply peaked gamma-ray spectrum without hard X-rays, challenges traditional models of diffusive shock acceleration…

High Energy Astrophysical Phenomena · Physics 2015-06-04 Peter Sturrock , Markus J. Aschwanden

Bulk energization of electrons to $10\,-\,20\,$keV in solar flares is attributed to dissipation of Alfv\'en waves that transport energy and potential downward to an acceleration region near the chromosphere. The acceleration involves the…

Solar and Stellar Astrophysics · Physics 2013-07-31 D. B. Melrose , M. S. Wheatland

In space and astrophysical plasmas, like in planetary magnetospheres, as that of Mercury,energetic electrons are often found near current sheets (CSs), which hints at electron acceleration by magnetic reconnection. Unfortunately, electron…

Plasma Physics · Physics 2018-07-04 X. Zhou , J. Buechner , F. Widmer , P. A. Munoz

We investigate the deceleration of Solar Energetic Particles (SEPs) during their propagation from the Sun through interplanetary space, in the presence of weak to strong scattering in a Parker spiral configuration, using relativistic full…

Solar and Stellar Astrophysics · Physics 2015-08-17 S. Dalla , M. S. Marsh , T. Laitinen