Study of the spectrum beyond 200 keV of second-stage solar flare X-ray emission

Journal Article · Fri Feb 01 04:00:00 EST 1980 · Astrophys. J.; (United States)

DOI:https://doi.org/10.1086/157708· OSTI ID:5295377

Langer, S H; Petrosian, V; Frost, K J

We have studied the spectra of three solar flares with second-stage hard X-ray emission observed by instruments on board the OSO 5 spacecraft. Using a Monte Carlo program, we have calculated the expected flux of solar X-rays reflected from the Earth's atmosphere for the observed solar X-ray spectra. The results have been compared with the observed reflected fluxes, which were also detected by the above instruments. We show that for the events considered here, which are necessarily intense and have hard spectra, the simple extrapolation of the observed solar spectrum to higher energies cannot explain the observed flux of the reflected radiation. Instead, we find the need to postulate the existence of a solar X-ray flux at energies above 200 keV larger than that obtained from simple extrapolation. In particular, we find evidence against a thermal spectrum in at least one of the events considered.

• Research Organization: Institute for Plasma Research, Stanford University
• OSTI ID: 5295377
• Journal Information: Astrophys. J.; (United States), Journal Name: Astrophys. J.; (United States) Vol. 235:3; ISSN ASJOA
• Country of Publication: United States
• Language: English

Related Subjects

640104* -- Astrophysics & Cosmology-- Solar Phenomena
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
EARTH ATMOSPHERE
ELECTROMAGNETIC RADIATION
HARD X RADIATION
IONIZING RADIATIONS
MAGNETOSPHERE
MONTE CARLO METHOD
RADIATION FLUX
RADIATIONS
SOLAR ACTIVITY
SOLAR FLARES
SOLAR X-RAY BURSTS
SPECTRA
X RADIATION
X-RAY SPECTRA