V. L. A. observations of flare build-up in coronal loops

Journal Article · Sun Jan 01 04:00:00 EST 1984 · Adv. Space Res.; (United States)

DOI:https://doi.org/10.1016/0273-1177(84)90167-4· OSTI ID:5672031

Lang, K R; Willson, R F

Very Large Array (VLA) measurements at 20-cm wavelength map emission from coronal loops with second-of-arc angular resolution at time intervals as short as 3.3 sec. The total intensity of the 20-cm emission describes the evolution and structure of the hot plasma that is detected by satellite X-ray observations of coronal loops. The circular polarization of the 20-cm emission describes the evolution, strength, and structure of the coronal magnetic field. Preburst heating and magnetic changes that precede burst emission on time scales of between 1 and 30 minutes are discussed. Simultaneous 20-cm and soft X-ray observations indicate an electron temperature of 2.5 x 10 to the 7th K and electron density of 10 to the 10th/cu cm during preburst heating in a coronal loop that was also associated with twisting of the entire loop in space. The successive triggering of bursts from adjacent coronal loops, highly polarized emission from the legs of loops with large intensity changes over a 32-MHz change in observing frequency, and apparent motions of hot plasma within coronal loops at velocities of over 2000 km/sec are also discussed. 25 references.

• Research Organization: Tufts Univ., Medford, MA
• OSTI ID: 5672031
• Journal Information: Adv. Space Res.; (United States), Journal Name: Adv. Space Res.; (United States) Vol. 4; ISSN ASRSD
• Country of Publication: United States
• Language: English

Related Subjects

640104* -- Astrophysics & Cosmology-- Solar Phenomena
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ATMOSPHERES
ELECTROMAGNETIC RADIATION
HEATING
HOT PLASMA
MAGNETIC FIELDS
MICROWAVE RADIATION
PLASMA
PLASMA HEATING
RADIATIONS
RADIOWAVE RADIATION
SOLAR ACTIVITY
SOLAR CORONA
SOLAR FLARES
SOLAR RADIO BURSTS
STELLAR ATMOSPHERES
STELLAR CORONAE