The hard X-rays and gamma rays from solar flares

Journal Article · Wed Aug 01 00:00:00 EDT 1990 · Astrophysical Journal; (USA)

DOI:https://doi.org/10.1086/169085· OSTI ID:6150298

Mctiernan, J M; Petrosian, V ^[1]

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1. Stanford Univ., CA (USA)

Radiation of energies from 10 KeV to greater than 10 MeV has been observed during solar flares, and is interpreted to be due to bremsstrahlung by relativistic electrons. A complete treatment of this problem requires solution of the kinetic equation for relativistic electrons and inclusion of synchrotron energy losses. Using the electron distributions obtained from numerical solutions of this equation the bremsstrahlung spectra in the impulsive X-ray and gamma ray regimes are calculated, and the variation of these spectral indices and directivities with energy and observation angle are described. The dependences of these characteristics of the radiation of changes in the solar atmospheric model, including the convergence of the magnetic field, the injected electron spectral index, and most importantly, in the anisotropy of the injected electrons and of the convergence of the magnetic field are also described. The model results are compared with stereoscopic observations of individual flares and the constraints that this data sets on the models are discussed. 21 refs.

• OSTI ID: 6150298
• Journal Information: Astrophysical Journal; (USA), Journal Name: Astrophysical Journal; (USA) Vol. 359; ISSN ASJOA; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

640104* -- Astrophysics & Cosmology-- Solar Phenomena
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ANISOTROPY
ATMOSPHERES
BREMSSTRAHLUNG
ELECTROMAGNETIC RADIATION
ELECTRONS
ELEMENTARY PARTICLES
ENERGY LOSSES
ENERGY RANGE
EQUATIONS
FERMIONS
GAMMA RADIATION
HARD X RADIATION
IONIZING RADIATIONS
KINETIC EQUATIONS
LEPTONS
LOSSES
MAGNETIC FIELDS
MATHEMATICAL MODELS
RADIATIONS
RELATIVISTIC RANGE
SOLAR ACTIVITY
SOLAR ATMOSPHERE
SOLAR FLARES
STAR MODELS
X RADIATION