E-Print Archive

There are 4021 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
Three-dimensional reconstruction of CME-driven shock-streamer interaction from radio observations: a different take on the diagnostics of coronal magnetic fields
The soft X-ray spectrometer polarimeter SolpeX
Variable emission mechanism of a Type IV radio burst
Inference of magnetic field strength and density from damped transverse coronal waves
Frequency-Distance Structure of Solar Radio Sources Observed by LOFAR
The birth of a coronal mass ejection
Properties of slow magnetoacoustic oscillations of solar coronal loops by multi-instrumental observations
Persistent Quasi-Periodic Pulsations During a Large X-Class Solar Flare
Magnetic helicity and fluxes in an inhomogeneous α squared dynamo
Properties of the Diffuse Emission around Warm Loops in Solar Active Regions
Comparative Study of Microwave Polar Brightening, Coronal Holes, and Solar Wind Over the Solar Poles
3He-rich Solar Energetic Particles from Sunspot Jets
Relative magnetic field line helicity
Forbush decreases and Geomagnetic Storms during a Highly Disturbed Solar and Interplanetary Period, 4‐10 September 2017
Helical Twisting Number and Braiding Linkage Number of Solar Coronal Loops
Small-scale motions in solar filaments as the precursors of eruptions
Modeling of Heliospheric Modulation of Cosmic-Ray Positrons in a Very Quiet Heliosphere
Interpreting magnetic helicity flux in solar flux emergence
Transient Inverse-FIP Plasma Composition Evolution within a Confined Solar Flare
The Role of a Tiny Brightening in a Huge Geo-effective Solar Eruption Leading to the St Patrick's Day Storm

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