VLA observations of the coronal plasma

Lang, Kenneth R.

VLA observations at 20 cm wavelength specify the brightness temperature and magnetic structure of plasma constrained within coronal loops in solar active regions. Comparisons with simultaneous SMM observations at soft x ray wavelengths lead to measurements of physical parameters like electron density, electron temperature and magnetic field strength. Such comparisons also indicate coronal loops can be detected at either radio or x ray wavelengths while remaining invisible in the other spectral domain, and that the dominant radiation mechanisms can be thermal bremsstrahlung or thermal gyroresonance radiation. VLA observations at the longer 90 cm wavelength reveal the thermal emission of a hot transition sheath enveloping a cooler, underlying H alpha filament seen in absorption. The 20 cm VLA observations indicate that the precursor, impulsive and post-flare components of solar flares originate in spatially separated and resolved sources. The 90 cm VLA data indicate that time-correlated radio bursts can occur in active regions on opposite sides of the solar equator. These regions are apparently linked by large scale, trans-equatorial magnetic loops at least 2.6 x 10(exp 5) km (or 6 feet) long; these loops act as magnetic conduits for relativistic electrons moving at one-third the velocity of light.

Document ID

19900012395

Acquisition Source

Legacy CDMS

Document Type

Conference Paper

Authors

Date Acquired

September 6, 2013

Publication Date

January 1, 1989

Subject Category

Report/Patent Number

Meeting Information

Meeting: IAU Symposium on Basic Plasma Processes on the Sun

Location: Bangalore

Country: India

Start Date: December 1, 1989

End Date: December 5, 1989

Accession Number

90N21711

Funding Number(s)

Distribution Limits

Public

Work of the US Gov. Public Use Permitted.

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