On the Possible Connection between Photospheric 5-Min Oscillation and Solar Flare Microwave Emission

• DOI: 10.1007/s11207-006-2850-y
• Publication Date: 2006-02-10T07:27:49Z
• Authors: A. G. Kislyakov; V. V. Zaitsev; A. V. Stepanov; S. Urpo
• Keywords: 01 natural sciences; 0105 earth and related environmental sciences

Dynamic spectra of low-frequency modulation of microwave emission from solar flares are obtained. Data of 15 bursts observed in 1989-2000 with Metsahovi radio telescope at 37 GHz have been used. During 13 bursts a 5-min modulation of the microwave emission intensity was detected with the frequency of νI = 3.2 ± 0.24 (1σ ) mHz. Five bursts revealed a 5-min wave superimposed on a ∼1 Hz, linear frequency modulated signal generated, presumably, by coronal magnetic loop, this wave frequency is νfm = 3.38 ± 0.37 (1σ ) mHz. Both intensity and frequency modulations detected are in good agreement with the data on 5-min global oscillations of photosphere and with the data on the umbral velocity oscillations observed in the vicinity of sunspots. Possible role of p-mode photospheric oscillations in modulation of microwave burst emission is discussed.