E-Print Archive

There are 4053 abstracts currently viewable.


Advanced Search
Main Page Add New E-Print Submitter
News Help/FAQ About Preferences
Manage Key Phrase
Hard X-ray footpoint sizes and positions as diagnostics of flare accelerated energetic electrons in the low solar atmosphere View all abstracts by submitter

Marina Battaglia   Submitted: 2011-04-17 23:37

The hard X-ray (HXR) emission in solar flares comes almost exclusively from avery small part of the flaring region, the footpoints of magnetic loops. UsingRHESSI observations of solar flare footpoints, we determine the radialpositions and sizes of footpoints as a function of energy in six near-limbevents to investigate the transport of flare accelerated electrons and theproperties of the chromosphere. HXR visibility forward fitting allows to findthe positions/heights and the sizes of HXR footpoints along and perpendicularto the magnetic field of the flaring loop at different energies in the HXRrange. We show that in half of the analyzed events, a clear trend of decreasingheight of the sources with energy is found. Assuming collisional thick-targettransport, HXR sources are located between 600 and 1200 km above thephotosphere for photon energies between 120 and 25 keV respectively. In theother events, the position as a function of energy is constant within theuncertainties. The vertical sizes (along the path of electron propagation)range from 1.3 to 8 arcseconds which is up to a factor 4 larger than predictedby the thick-target model even in events where the positions/heights of HXRsources are consistent with the collisional thick-target model. Magneticmirroring, collisional pitch angle scattering and X-ray albedo are discussed aspotential explanations of the findings.

Authors: Marina Battaglia, Eduard P. Kontar
Projects: RHESSI

Publication Status: ApJ, accepted
Last Modified: 2011-04-18 00:43
Go to main E-Print page  Coronal Shock Waves, EUV Waves, and Their Relation to CMEs. III. Shock-Associated CME/EUV Wave in an Event with a Two-Component EUV Transient  Instrumental oscillations in RHESSI count rates during solar flares  Edit Entry  Download Preprint  Submitter's Homepage Delete Entry 

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
Linear waves in a non-equilibrium ionisation partially ionised plasma
How Many Twists Do Solar Coronal Jets Release?
Different Signatures of Chromospheric Evaporation in Two Solar Flares Observed with IRIS
The Physical Nature of Spiral Wave Patterns in Sunspots
Predicting Solar Flares Using a Long Short-Term Memory Network
Coronal loop transverse oscillations excited by different driver frequencies
Solar Center-Limb Variation of the Strengths of Spectral Lines: Classification and Interpretation of Observed Trends
The plasmoid instability in a confined solar flare
High-frequency dynamics of active region moss as observed by IRIS
Extreme-ultraviolet Late Phase Caused by Magnetic Reconnection over Quadrupolar Magnetic Configuration in a Solar Flare
Two-step evolution of a rising flux rope resulting in a confined solar flare
Why torus-unstable solar filaments experience failed eruption?
The Magnetic Properties of Heating Events on High-Temperature Active Region Loops
Pulse-beam heating of deep atmospheric layers, their oscillations and shocks modulating the flare reconnection
A potential magnetic field calculator for solar physics applications using staggered grids
E and B polarizations from inhomogeneous and solar surface turbulence
Oscillations Accompanying a He I 10830 Å Negative Fare in a Solar Facula II. Response of the Transition Region and Corona
Flare reconnection-driven magnetic field and Lorentz force variations at the Sun's surface
Why Does the Solar Corona Abnormally Rotate Faster Than the Photosphere?
Impacts On Proton Fluxes Observed During Different Interplanetary Conditions

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