On the nature of microwave pulsations from solar active regions

1Gelfreikh, GB, 2Tsap, YT, 1Kopylova, YG, 2Tsvetkov, LI, 3Goldvarg, TB, 1Nagovitsin, YA, 2Yurovsky, YF, 2Budzinovskaya, IA
1Main Astronomical Observatory of the Russian Academy of Sciences, St. Petersburg, Russia
2Scientific-Research Institute «Crimean Astrophysical Observatory» of the Ministry for Education and Science of Ukraine, Nauchny, Crimea, Ukraine
3B.B. Gorodovikova Kalmyk State University, Elista, Republic of Kalmykia, Russia
Kosm. nauka tehnol. 2003, 9 ;(5-6):136-139
Publication Language: Russian
On the basis of observed data obtained with the radio telescope RT-22 of the Crimean Astrophysical Observatory at 8.6 and 15.4 GHz the quasi-periodic variations of microwave radiation from solar active regions with periods less then 10 min are investigated. The revealed oscillations with periods of 10–40s we connected with the Alfven disturbances. It was established that acoustic modes with periods less than 1 min strongly dissipate in lower corona due to the thermal conductivity. Within the framework of the homogeneous model the influence of acoustic and Alfven oscillations on the thermal mechanisms of microwave radiation is analyzed. The probable sources of the coronal heating are discussed.
Keywords: microwave pulsations, solar active regions, Sun's corona
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