E-Print Archive

There are 3991 abstracts currently viewable.


Search:

Advanced Search
Options
Main Page Add New E-Print Submitter
Information
Feedback
News Help/FAQ About Preferences
Manage Key Phrase
Notification
Energy Release and Particle Acceleration in Flares: Summary and Future Prospects View all abstracts by submitter

Amir Caspi   Submitted: 2011-10-28 12:23

RHESSI measurements relevant to the fundamental processes of energy releaseand particle acceleration in flares are summarized. RHESSI's precisemeasurements of hard X-ray continuum spectra enable model-independentdeconvolution to obtain the parent electron spectrum. Taking into account theeffects of albedo, these show that the low energy cut-off to the electronpower-law spectrum is typically below tens of keV, confirming that theaccelerated electrons contain a large fraction of the energy released inflares. RHESSI has detected a high coronal hard X-ray source that is filledwith accelerated electrons whose energy density is comparable to themagnetic-field energy density. This suggests an efficient conversion of energy,previously stored in the magnetic field, into the bulk acceleration ofelectrons. A new, collisionless (Hall) magnetic reconnection process has beenidentified through theory and simulations, and directly observed in space andin the laboratory; it should occur in the solar corona as well, with areconnection rate fast enough for the energy release in flares. Thereconnection process could result in the formation of multiple elongatedmagnetic islands, that then collapse to bulk-accelerate the electrons, rapidlyenough to produce the observed hard X-ray emissions. RHESSI's pioneering{gamma}-ray line imaging of energetic ions, revealing footpoints straddling aflare loop arcade, has provided strong evidence that ion acceleration is alsorelated to magnetic reconnection. Flare particle acceleration is shown to havea close relationship to impulsive Solar Energetic Particle (SEP) eventsobserved in the interplanetary medium, and also to both fast coronal massejections and gradual SEP events.

Authors: R.P. Lin
Projects: GONG,Hinode/EIS,Hinode/SOT,Hinode/XRT,Nobeyama Radioheliograph,Owens Valley Solar Array,RHESSI,SDO-AIA,SDO-HMI,SDO-EVE,SoHO-EIT,SoHO-MDI,SoHO-CDS,SoHO-LASCO,SoHO-SUMER,STEREO,TRACE

Publication Status: Published -- Lin, R. P. 2011, Space Sci. Rev., 159, 421; DOI 10.1007/s11214-011-9801-0
Last Modified: 2011-11-17 14:21
Go to main E-Print page  Frequency drifts of 3-min oscillations in microwave and EUV emission above sunspots  Deducing Electron Properties From Hard X-Ray Observations  Edit Entry  Download Preprint  Delete Entry 

Key
Go to main E-Print pageGo to main E-Print page.
Previous AbstractPrevious Abstract.
Next AbstractNext Abstract.
Download PreprintDownload Preprint.
Submitter's HomepageSubmitters Homepage.
Edit EntryEdit Entry.
View All Abstracts By SubmitterView all abstracts by submitter.
Delete AbstractDelete abstract.

Latest Entries
Investigation of pre-flare dynamics using the weighted horizontal magnetic gradient method: From small to major flare classes
Seismological determination of the Alfvén speed and plasma-beta in solar photospheric bright points
Dynamo Wave Patterns Inside the Sun Revealed by Torsional Oscillations
Evidence of Twisting and Mixed-polarity Solar Photospheric Magnetic Field in Large Penumbral Jets: IRIS and Hinode Observations
Dissipation scale lengths of density turbulence in the inner solar wind
On the Possibility of Generating Harmonics of the Electron Plasma Frequency in the Solar Atmosphere due to Explosive Instability in a System of Interpenetrating Electron and Ion Flows
Determination of the total accelerated electron rate and power using solar flare hard X-ray spectra
Transition from axi- to nonaxisymmetric dynamo modes in spherical convection models of solar-like stars
Can high-mode magnetohydrodynamic waves propagating in a spinning macrospicule be unstable due to the Kelvin-Helmholtz instability?
The development of lower-atmosphere turbulence early in a solar flare
Determining the parameter for the linear force-free magnetic field model with multi-dipolar configurations using deep neural networks
No unique solution to the seismological problem of standing kink MHD waves
Untwisting and Disintegration of a Solar Filament Associated with Photospheric Flux Cancellation
Modeling of the sunspot-associated microwave emission using a new method of DEM inversion
Energy transport and heating by torsional Alfvén waves propagating from the photosphere to the corona in the quiet Sun
A Two-Step Magnetic Reconnection in a Confined X-class Flare in Solar Active Region 12673
Lifetimes and Emergence/Decay Rates of Star Spots on Solar-type Stars Estimated by Kepler Data in Comparison with Those of Sunspots
IRIS and SDO Observations of Solar Jetlets Resulting from Network-edge Flux Cancelation
Si IV Resonance Line Emission During Solar Flares: Non-LTE, Non-equilibrium, Radiation Transfer Simulations
Study of current sheets in the wake of two crossing filaments eruption

Related Pages
MSU Solar Physics.
Max Millennium Science Mail Archive.
Max Millennium Message of the Day Mail Archive.
Max Millennium Flare Catalog

Archive Maintainer
Alisdair Davey



© 2003 Solar Physics Group - Montana State University