๐”– Bobbio Scriptorium
โœฆ   LIBER   โœฆ

Solar active regions at millimeter wavelengths

โœ Scribed by M. R. Kundu

Publisher
Springer
Year
1970
Tongue
English
Weight
516 KB
Volume
13
Category
Article
ISSN
0038-0938

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โœฆ Synopsis

Some properties of solar active regions at 9, 3.5 and 1.2 mm wavelengths are discussed. The regions have excess brightness temperatures of up to 1000, 700 and 150 K at 9, 3.5 and 1.2 mm wavelengths. The background radiation at 3.5 mm is often seen to be 'absorbed' in regions closely coincident with Ha dark filaments on the disk. Interpretation of this 'absorption' as due to the large optical thickness of the overlying filamentary material leads to an estimate of electron density in the filaments. The 9 and 3.5 mm-~. regions show almost one-to-one correspondence with the Ca-plage regions as well as with the regions on magnetograms. The latter relationship suggests the possibility of measuring chromospheric magnetic fields from the measurement of polarization at millimeter wavelengths.

๐Ÿ“œ SIMILAR VOLUMES

Polarization of solar active regions at
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โœ M. R. Kundu; T. Gergely ๐Ÿ“‚ Article ๐Ÿ“… 1973 ๐Ÿ› Springer ๐ŸŒ English โš– 432 KB

A study of the circular polarization structure of solar active regions has been made from data obtained at 3.5 mm wavelength, using the 36 ft diameter radio telescope of the National Radio Astronomy Observatory at Kitt Peak, Arizona. The angular resolution of the telescope at this wavelength is 1:2.

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The solar brightness temperature at mill
The solar brightness temperature at millimeter wavelengths
โœ Richard A. Kuseski; Paul N. Swanson ๐Ÿ“‚ Article ๐Ÿ“… 1976 ๐Ÿ› Springer ๐ŸŒ English โš– 283 KB

The authors have previously discussed an improved method for obtaining the absolute solar brightness temperature using the new Moon as a calibration source. New measurements of the Sun-to-new Moon ratio at three frequencies near 36 GHz ()t = 8 mm) and also at two frequencies near 93 GHz ()t = 3 mm)

Solar active regions at 9 and 3.5 mm wav
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โœ M. R. Kundu; Sou-Yang Liu ๐Ÿ“‚ Article ๐Ÿ“… 1973 ๐Ÿ› Springer ๐ŸŒ English โš– 374 KB

Some properties of solar active regions at 9 and 3.5 mm wavelengths under disturbed conditions are discussed. New regions develop or weak regions intensify at millimeter wavelengths as a result of flares at distant sites. The spectra of the peak flux density of moderately strong bursts observed at 9