Stereoscopic observations of a solar flare hard X-ray source in the high corona

Journal Article · Fri May 01 04:00:00 EDT 1992 · Astrophysical Journal; (United States)

DOI:https://doi.org/10.1086/171320· OSTI ID:7036139

Kane, S R; Mctiernan, J; Loran, J; Fenimore, E E; Klebesadel, R W; Laros, J G ^[1]

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1. California, University, Berkeley (United States) Los Alamos National Laboratory, NM (United States)

The vertical structure of the impulsive and gradual hard X-ray sources in high coronae and the characteristics of the impulsive soft X-ray emission are investigated on the basis of PVE, ICE, and GOES observations of the energetic flare on February 16, 1984. The average photon spectra observed by these instruments during the impulsive and gradual hard X-ray bursts are summarized. A comparison of these unocculted and partially occulted spectra shows that the sources of the impulsive hard X-ray (greater than about 25 keV) and impulsive soft X-ray (2-5 keV) emissions in this flare extended to coronal altitudes greater than about 200,000 km above the photosphere. At about 100 keV, the ratio of the coronal source brightness to the total source brightness was 0.001 during the impulsive phase and less than about 0.01 during the gradual hard X-ray burst. The sources of the gradual hard X-ray burst and gradual soft X-ray burst were almost completely occulted, indicating that these sources were located at heights less than 200,000 km above the photosphere. 47 refs.

• OSTI ID: 7036139
• Journal Information: Astrophysical Journal; (United States), Journal Name: Astrophysical Journal; (United States) Vol. 390:2; ISSN ASJOA; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

661300* -- Other Aspects of Physical Science-- (1992-)
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ATMOSPHERES
COSMIC RAY SOURCES
COSMIC X-RAY SOURCES
ELECTROMAGNETIC RADIATION
GAMMA RADIATION
IONIZING RADIATIONS
RADIATIONS
SOFT X RADIATION
SOLAR ACTIVITY
SOLAR ATMOSPHERE
SOLAR CORONA
SOLAR FLARES
SOLAR X-RAY BURSTS
SPECTRA
STELLAR ATMOSPHERES
STELLAR CORONAE
X RADIATION
X-RAY SPECTRA