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Microwave imaging of a solar limb flare - Comparison of spectra and spatial geometry with hard X-raysA solar limb flare was mapped using the Very Large Array (VLA) together with hard X-ray (HXR) spectral and spatial observations of the Solar Maximum Mission satellite. Microwave flux records from 2.8 to 19.6 GHz were instrumental in determining the burst spectrum, which has a maximum at 10 GHz. The flux spectrum and area of the burst sources were used to determine the number of electrons producing gyrosynchrotron emission, magnetic field strength, and the energy distribution of gyrosynchrotron-emitting electrons. Applying the thick target model to the HXR spectrum, the number of high energy electrons responsible for the X-ray bursts was found to be 10 to the 36th, and the electron energy distribution was approximately E exp -5, significantly different from the parameters derived from the microwave observations. The HXR imaging observations exhibit some similiarities in size and structure o the first two burst sources mapped with the VLA. However, during the initial burst, the HXR source was single and lower in the corona than the double 6 cm source. The observations are explained in terms of a single loop with an isotropic high-energy electron distribution which produced the microwaves, and a larger beamed component which produced the HXR at the feet of the loop.
Document ID
19860049357
Acquisition Source
Legacy CDMS
Document Type
Reprint (Version printed in journal)
External Source(s)
Authors
Schmahl, E. J.
(Maryland Univ. College Park, MD, United States)
Kundu, M. R.
(Maryland, University College Park, United States)
Dennis, B. R.
(NASA Goddard Space Flight Center Greenbelt, MD, United States)
Date Acquired
August 12, 2013
Publication Date
December 15, 1985
Publication Information
Publication: Astrophysical Journal, Part 1
Volume: 299
ISSN: 0004-637X
Subject Category
Solar Physics
Accession Number
86A34095
Funding Number(s)
CONTRACT_GRANT: NGR-21-002-199
CONTRACT_GRANT: NSF ATM-84-15388
CONTRACT_GRANT: NSG-5320
Distribution Limits
Public
Copyright
Other

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