Two-frequency imaging of microwave impulsive flares near the solar limb

Journal Article · Wed Jan 01 04:00:00 EST 1986 · Astrophys. J.; (United States)

DOI:https://doi.org/10.1086/163818· OSTI ID:5961836

Dulk, G A; Bastian, T S; Kane, S R

Using the VLA, we observed two impulsive microwave and hard X-ray flares that occurred close to the solar limb on 1981 November 21 and 22. Images were obtained simultaneously at 4.9 and 15 GHz every 10 s during the 5 minute durations of the flares. Even though the radio and hard X-ray time histories indicated that they were simple impulsive flares, the VLA observed no 4.9 GHz radiation at all from one flare. From the other, the 15 GHz radiation emanated from a smaller source at a lower altitude and a different position angle than did the 4.9 GHz radiation; furthermore, the degree and sense of circular polarization differed in the two sources, and both showed complicated variations with time.

• Research Organization: Department of Astrophysical, Planetary and Atmospheric Science, University of Colorado, Boulder
• OSTI ID: 5961836
• Journal Information: Astrophys. J.; (United States), Journal Name: Astrophys. J.; (United States) Vol. 300:1; ISSN ASJOA
• Country of Publication: United States
• Language: English

Related Subjects

640104* -- Astrophysics & Cosmology-- Solar Phenomena
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ABSORPTION
BREMSSTRAHLUNG
ELECTROMAGNETIC RADIATION
ELECTRONS
ELEMENTARY PARTICLES
FERMIONS
GYROFREQUENCY
HARD X RADIATION
HARMONICS
INTERFEROMETRY
IONIZING RADIATIONS
LEPTONS
MAGNETIC FIELDS
MICROWAVE RADIATION
OSCILLATIONS
POLARIZATION
RADIATIONS
RADIOWAVE RADIATION
SOLAR ACTIVITY
SOLAR ELECTRONS
SOLAR FLARES
SOLAR PARTICLES
SOLAR RADIATION
SOLAR RADIOWAVE RADIATION
STELLAR RADIATION
X RADIATION