HR: 0830h
AN: SP21A-05    [Abstracts]
TI: Comparison of Algorithms for Reconstructing Electron Spectra from Solar Flare Hard X-Ray Spectra
AU: * Emslie, G
EM: gordon.emslie@okstate.edu
AF: Oklahoma State University, Department of Physics, Stillwater, OK 74078 United States
AU: Brown, J C
EM: john@astro.gla.ac.uk
AF: University of Glasgow, Department of Physics & Astronomy, Glasgow, G12 8QQ United Kingdom
AU: Holman, G D
EM: holman@stars.gsfc.nasa.gov
AF: NASA Goddard Space Flight Center, Code 682, Greenbely, MD 20771 United States
AU: Johns-Krull, C
EM: cmj@rice.edu
AF: Rice University, Department of Physics & Astronomy, Houston, TX 77005 United States
AU: Kontar, E P
EM: eduard@astro.gla.ac.uk
AF: University of Glasgow, Department of Physics & Astronomy, Glasgow, G12 8QQ United Kingdom
AU: Massone, A M
EM: massone@ge.infm.it
AF: INFM-LAMIA, via Dodecaneso 33, Genova, I-16146 Italy
AU: Piana, M
EM: piana@dima.unige.it
AF: Universita di Genova, Dipartimento di Matematica, Genova, I-16146 Italy
AB: The Ramaty High Energy Solar Spectroscopic Imager (RHESSI) is yielding solar flare hard X-ray (HXR) spectra with unprecedented resolution and precision. Such spectra enable the reconstruction of the effective mean source electron spectrum F̅(E) by deconvolution of the photon spectrum I(ε) through the bremsstrahlung cross-section Q(ε,E). In this paper we report on an evaluation of three distinct "inverting" reconstruction techniques and one forward fitting procedure. We synthesized a variety of hypothetical F̅(E) forms, with a variety of empirical features designed to represent diagnostics of electron acceleration and transport processes, generated the corresponding I(ε) with realistic random noise added, and performed "blind" (i.e. without knowledge of F̅[E] in advance) recoveries of F̅(E) for comparison with the originally assumed forms. In most cases the inversion methods gave very good reconstructions of F̅(E). The forward fitting method did well in recovering large-scale features but, somewhat inevitably, failed to recover features outwith the parametric forms of F̅(E), such as dips, bumps and positive slopes. However, examination of the distribution of photon spectrum residuals over ε should in principle permit refinement of the parametric form used.
DE: 7519 Flares
DE: 7554 X rays, gamma rays, and neutrinos
SC: Solar Physics Division - AAS [SP]
MN: 2005 Joint Assembly