E-Print Archive

There are 3928 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
Characteristics of Solar Flare Hard X-ray Emissions: Observations and Models View all abstracts by submitter

Wei Liu   Submitted: 2006-12-21 01:12

The main theme of this thesis is the investigation of the physics of acceleration and transport of particles in solar flares, and their thermal and nonthermal radiative signatures. The observational studies, using hard X-rays (HXRs) observed by the RHESSI mission, concentrate on four flares, which support the classical magnetic reconnection model of solar flares in various ways. In the X3.9 flare occurring on 11/03/2003, there is a monotonic upward motion of the loop top (LT) source accompanied by a systematic increase in the separation of the footpoint (FP) sources at a comparable speed. This is consistent with the reconnection model with an inverted-Y geometry. The 04/30/2002 event exhibits rarely observed two coronal sources. The two sources (with almost identical spectra) show energy-dependent structures, with higher-energy emission being close together. This suggests that reconnection takes place within the region between the sources. In the 10/29/2003 X10 flare, the logarithmic total HXR flux of the FPs correlates with the mean magnetic field. The two FPs show asymmetric HXR fluxes, which is qualitatively consistent with the magnetic mirroring effect. The M1.7 flare on 11/13/2003 reveals evidence of evaporation directly imaged by RHESSI for the first time, in which emission from the legs of the loop appears at intermediate energies. The emission centroid moves toward the LT as time proceeds, indicating an increase of density in the loop. The theoretical modeling of this work combines the stochastic acceleration model with the NRL hydrodynamic model to study the interplay of the particle acceleration, transport, and radiation effects and the atmospheric response to the energy deposition by nonthermal electrons. We find that low-energy electrons in the quasi-thermal portion of the spectrum affects the hydrodynamics by producing more heating in the corona than the previous models that used a power-law spectrum with a low-energy cutoff. The Neupert effect is found to be present and effects of suppression of conduction are tested in the presence of hydrodynamic flows.

Authors: Wei Liu (Adviser: Vahe' Petrosian)
Projects: RHESSI

Publication Status: 2006, Ph.D. Thesis, Stanford University (10 chapters, 224 pages)
Last Modified: 2006-12-21 09:54
Go to main E-Print page  Testing non-linear force-free coronal magnetic field extrapolations with the Titov-Demoulin equilibrium  The origin of the reversed granulation in the solar photosphere  Edit Entry  Download Preprint  Submitter's Homepage 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
Diagnostic Analysis of the Solar Proton Flares of September 2017 by Their Radio Bursts
Densities Probed by Coronal Type III Radio Burst Imaging
The Minimum Energy Principle Applied to Parker's Coronal Braiding and Nanoflaring Scenario
Eruptions from quiet Sun coronal bright points. I. Observations
Evolution of the transverse density structure of oscillating coronal loops inferred by forward modelling of EUV intensity
Non-stationary quasi-periodic pulsations in solar and stellar flares
Lost and found sunquake in the 6 September 2011 flare caused by beam electrons
Nonkinematic solar dynamo models with double-cell meridional circulation
Solar Kinetic Energy and Cross Helicity Spectra
Collective Study of Polar Crown Filaments in the Past Four Solar Cycles
Highly Ionized Calcium and Argon X-ray Spectra from a Large Solar Flare
Detecting the solar new magnetic flux regions on the base of vector magnetograms
A Truly Global EUV Wave From the SOL2017-09-10 X8.2 Solar Flare-CME Eruption
ALTERNATIVE ZEBRA-STRUCTURE MODELS IN SOLAR RADIO EMISSION
Photospheric Shear Flows in Solar Active Regions and Their Relation to Flare Occurrence
Linear Polarization Features in the Quiet-Sun Photosphere: Structure and Dynamics
Solar Microflares Observed by SphinX and RHESSI
Two Kinds of Dynamic Behavior in a Quiescent Prominence Observed by the NVST
Resistively-limited current sheet implosions in planar anti-parallel (1D) and null-point containing (2D) magnetic field geometries
Is It Small-scale Weak Magnetic Activity That Effectively Heats the Upper Solar Atmosphere?

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