Spectral features of millimetre emission of solar active regions.
Abstract
From solar maps at 3.4 mm wavelength obtained with RT 7.5 radio telescope of Moscow State Technical University and solar maps at 17.6 mm wavelength from Japan Nobeyama heliograph, spectral characteristics of sources of slowly varying component have been studied. It has been shown that two components in millimetre radio emission of an active region can be resolved: sunspot emission and plage emission. Their contribution into total flux density of the active region are different at 3.4 mm and 17.6 mm wavelengths. At the wavelength of 3.4 mm the brightness temperature of a source over sunspot group does not differ much from the brightness temperature of the whole active region. Disagreement between the observational data obtained at mm domain and the standard chromosphere models is discussed.
- Publication:
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JOSO Annu. Rep., 1997
- Pub Date:
- 1998
- Bibcode:
- 1998joso.proc...99N
- Keywords:
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- Solar Active Regions: MM Radiation