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Two-dimensional mapping of the Sun with the RATAN-600

โœ Scribed by A. Nindos; C. E. Alissandrakis; G. B. Gelfreikh; V. N. Borovik; A. N. Korzhavin; V. M. Bogod


Book ID
104642646
Publisher
Springer
Year
1996
Tongue
English
Weight
958 KB
Volume
165
Category
Article
ISSN
0038-0938

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โœฆ Synopsis


We present two-dimensional solar maps at 2.7, 3.2, 4, and 8.2 cm computed from onedimensional observations with the RATAN-600, using Earth rotation aperture synthesis techniques. Before the calculation of maps, the position of each scan was corrected with respect to the center of the solar disk and the scans were calibrated. The circular polarization scans were corrected for polarization cross-talk between the I and V channels. Subsequently, the quiet-Sun background emission was subtracted. After all corrections, a dirty map was computed by combining the scans at different position angles. The last step of the processing was an attempt to free the dirty map of the sidelobes, using the standard CLEAN procedure. The resolution of the clean maps at 2.7 cm was 0.5 ~ by 6 I. Both active regions which were present on the solar disk were mapped. We studied the flux spectra of different types of sources: one was associated with a sunspot, the second was located over the neutral line of an active region, and the other was associated with the plage. The emission mechanism of the former was attributed to the gyroresonance process, while the short wavelength emission of the others was attributed to the free-free process. For the sunspot-associated source we estimated the magnetic field strengths at the base of the transition region and in the low corona.


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