Joint Fitting of the Gamma-Ray Spectrum and Neutron-Capture Line Decay Profile and Normalization to Constrain Ion Acceleration in Large Flares
type: Dataset
description: We use the RHESSI (Reuven Ramaty High Energy Solar Spectroscopic Imager) to study solar flare gamma rays that are signatures of the accelerated ions. Specifically, we analyze the prominent 2.2 MeV line due to neutron capture whose time profile depends on the ambient 3He/H ratio, accelerated ion spectral index and incident ion angular distribution. For the first time we fit the 2.2 MeV time profile and overall normalization jointly with a full spectral fit to find a minimum in the total chi-square. This allows for self-consistent constraints on many of the flaring environment parameters, including the energetic particle spectral index, degree of pitch angle scattering, ambient abundances including 3He, accelerated abundances, magnetic field convergence, and the effective angle of the flare. The temporal model consists of a kernel (the response to a delta-function particle injection) convolved with the observed 4-7MeV flux, dominated by prompt nuclear emission. The spectral fitting includes a recently improved model of the nuclear de- excitation continuum. By comparing fits of multiple flares we provide stronger constrains on the flare environment parameters as well as best current constraint to the 3He/H abundance in the sun.
landing page: American Geophysical Union, Fall Meeting 2008
keyword: 7514-energetic-particles-2114
keyword: 7519-flares
keyword: 7554-x-rays
keyword: 7594-instruments-and-techniques
keyword: and-neutrinos
keyword: conference-papers
keyword: gamma-rays
keyword: infoeu-reposemanticsconferenceobject
keyword: physastrhephysics-physicsastrophysics-astro-phhigh-energy-astrophysical-phenomena-astro-p
keyword: sduastrhesciences-of-the-universe-physicsastrophysics-astro-phhigh-energy-astrophysical-ph
issued: 2026-05-09T23:22:38.893274
modified: 2026-05-09T23:22:38.893278
language: en
contact point: Organization
  fn: CCSD

test_moissonnage_selune
type: Agent

Joint Fitting of the Gamma-Ray Spectrum and Neutron-Capture Line Decay Profile and Normalization to Constrain Ion Acceleration in Large Flares
type: Distribution
format: HTML
access URL: https://in2p3.hal.science/in2p3-00855680
issued: 2026-05-09T23:22:38.894670
modified: 2026-05-09T23:22:38.881619