Implications of X-ray Observations for Electron Acceleration and Propagation in Solar Flares

@article{Holman2011ImplicationsOX,
  title={Implications of X-ray Observations for Electron Acceleration and Propagation in Solar Flares},
  author={Gordon D. Holman and Markus J. Aschwanden and Henry Aurass and Marina Battaglia and Paolo C. Grigis and Eduard P. Kontar and W. Liu and P. Saint-Hilaire and Valentina V. Zharkova},
  journal={Space Science Reviews},
  year={2011},
  volume={159},
  pages={107-166}
}
High-energy X-rays and γ-rays from solar flares were discovered just over fifty years ago. Since that time, the standard for the interpretation of spatially integrated flare X-ray spectra at energies above several tens of keV has been the collisional thick-target model. After the launch of the Reuven Ramaty High Energy Solar Spectroscopic Imager (RHESSI) in early 2002, X-ray spectra and images have been of sufficient quality to allow a greater focus on the energetic electrons responsible for… 

The collisional relaxation of electrons in hot flaring plasma and inferring the properties of solar flare accelerated electrons from X-ray observations.

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

Time Evolution of the Energy Spectra of Accelerated Electrons and Hard X-Rays from Local Sources of Solar Flares

Modern observations of solar flares in hard X-rays are carried out with a high spatial resolution of ~2–4 arcsec with the RHESSI satellite. In this way one can identify, at least for powerful events,

Solar flares and energetic particles

  • N. Vilmer
  • Physics
    Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences
  • 2012
The available information on energetic particles provided by X-ray/γ-ray observations is reviewed, with particular emphasis on the results obtained recently by the mission Reuven Ramaty High-Energy Solar Spectroscopic Imager.

Implications for electron acceleration and transport from non-thermal electron rates at looptop and footpoint sources in solar flares

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.

NUMERICAL SIMULATIONS OF CHROMOSPHERIC HARD X-RAY SOURCE SIZES IN SOLAR FLARES

X-ray observations are a powerful diagnostic tool for transport, acceleration, and heating of electrons in solar flares. Height and size measurements of X-ray footpoint sources can be used to

Determination of the Total Accelerated Electron Rate and Power Using Solar Flare Hard X-Ray Spectra

Solar flare hard X-ray (HXR) spectroscopy serves as a key diagnostic of the accelerated electron spectrum. However, the standard approach using the collisional cold thick-target model poorly

ON THE VARIATION OF SOLAR FLARE CORONAL X-RAY SOURCE SIZES WITH ENERGY

Observations with RHESSI have enabled the detailed study of the structure of dense hard X-ray coronal sources in solar flares. The variation of source extent with electron energy has been discussed

Radio and X-Ray Observations of Short-lived Episodes of Electron Acceleration in a Solar Microflare

Solar flares are sudden energy release events in the solar corona, resulting from magnetic reconnection, that accelerate particles and heat the ambient plasma. During a flare, there are often

MULTITHERMAL REPRESENTATION OF THE KAPPA-DISTRIBUTION OF SOLAR FLARE ELECTRONS AND APPLICATION TO SIMULTANEOUS X-RAY AND EUV OBSERVATIONS

Acceleration of particles and plasma heating is one of the fundamental problems in solar flare physics. An accurate determination of the spectrum of flare-energized electrons over a broad energy

Probing solar flare accelerated electron distributions with prospective X-ray polarimetry missions

Solar flare electron acceleration is an extremely efficient process, but the method of acceleration is not well constrained. Two of the essential diagnostics, electron anisotropy (velocity angle to
...

References

SHOWING 1-10 OF 209 REFERENCES

Energetic electrons in solar flares as viewed in X-rays

RHESSI Hard X-Ray Imaging Spectroscopy of Extended Sources and the Physical Properties of Electron Acceleration Regions in Solar Flares

In this study we present the results of a new approach to studying the acceleration and propagation of bremsstrahlung-producing electrons in solar flares. The method involves an analysis of the size

Hard X-ray emission from the solar corona

This review surveys hard X-ray emissions of non-thermal electrons in the solar corona. These electrons originate in flares and flare-related processes. Hard X-ray emission is the most direct

RHESSI Observations of the Neupert Effect in Three Solar Flares

Previous observations show that in many solar flares there is a causal correlation between the hard X-ray flux and the derivative of the soft X-ray flux. This so-called Neupert effect is indicative

Spectral features in solar hard X-ray and radio events and particle acceleration.

Hard x-ray and radio intensities of two major solar outbursts are found to anticorrelate in time with their spectral indices, which, furthermore, are in satisfactory correlation with each other. The

Electron Bremsstrahlung Hard X-Ray Spectra, Electron Distributions, and Energetics in the 2002 July 23 Solar Flare

We present and analyze the first high-resolution hard X-ray spectra from a solar flare observed in both X-ray/γ-ray continuum and γ-ray lines. Spatially integrated photon flux spectra obtained by the

Coronal γ-Ray Bremsstrahlung from Solar Flare-accelerated Electrons

The Reuven Ramaty High Energy Spectroscopic Imager (RHESSI) provides for the first time imaging spectroscopy of solar flares up to the γ-ray range. The three RHESSI flares with best counting

THE X-RAY DETECTABILITY OF ELECTRON BEAMS ESCAPING FROM THE SUN

We study the detectability and characterization of electron beams as they leave their acceleration site in the low corona toward interplanetary space through their nonthermal X-ray bremsstrahlung

Inverse Compton X-rays from relativistic flare electrons and positrons

Context. In solar flares, inverse Compton scattering (ICS) of photospheric photons might give rise to detectable hard X-ray photon fluxes from the corona where ambient densities are too low for

Electron acceleration by the reconnection outflow shock during solar flares

During solar flares a large amount of nonthermal electromagnetic radiation up to the γ -ray range is emitted from the corona, which implies that energetic electrons are generated. Within the
...