Multiple-wavelength analysis of energy release during a solar flare - Thermal and nonthermal electron populations

Journal Article · Sun Jul 01 04:00:00 EDT 1990 · Astrophysical Journal; (USA)

DOI:https://doi.org/10.1086/168955· OSTI ID:6594397

Willson, R F; Lang, K R; Klein, K L; Kerdraon, A; Trottet, G ^[1]

---

1. Tufts Univ., Medford, MA (USA) Paris Observatoire, Meudon (France)

Collaborative solar investigations by Tufts University and the Observatoire de Paris have resulted in simultaneous radio observations with the Very Large Array (VLA) and the Nancay Radioheliograph (NR), comparisons of this radio data with X-ray observations, and theoretical interpretations of the dominant radiation mechanisms during a weak impulsive solar flare observed on May 28, 1988. The VLA has mapped the flaring structures at time intervals of 3.3 s, showing that the preflash and flash-phase components of the impulsive emission originate in spatially separated sources. The 20.7 cm preflash source is ascribed to thermal gyroresonance emission from coronal loops with typical magnetic field strengths of up to 270 G; this emission is associated with heating and exhibits no detectable hard X-ray radiation above 30 keV. The flash-phase 20.7 cm source and the hard X-ray emission are attributed to nonthermal electrons in the coronal and chromospheric portions of a magnetic loop. The combination of imaging observations at 20.7 and 91.6 cm excludes emission from a confined hot plasma during the flash phase. 42 refs.

• OSTI ID: 6594397
• Journal Information: Astrophysical Journal; (USA), Journal Name: Astrophysical Journal; (USA) Vol. 357; 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
ATMOSPHERES
COMPARATIVE EVALUATIONS
ELECTROMAGNETIC RADIATION
ELECTRON DENSITY
ELECTRONS
ELEMENTARY PARTICLES
ENERGY SOURCES
FERMIONS
HARD X RADIATION
HOT PLASMA
IONIZING RADIATIONS
LEPTONS
MAGNETIC FIELDS
PLASMA
RADIATIONS
RADIOWAVE RADIATION
SOLAR ACTIVITY
SOLAR CORONA
SOLAR ELECTRONS
SOLAR FLARES
SOLAR PARTICLES
SOLAR RADIATION
SOLAR RADIO BURSTS
STELLAR ATMOSPHERES
STELLAR CORONAE
STELLAR RADIATION
THERMAL RADIATION
X RADIATION