L.V. Yasnov1, V.M. Bogod2, A.G. Stupishin2
1Research Institute of
Radiophysics, St.Petersburg State University, Russia
2Special Astrophysical Observatory,
Russian Academy of Sciences, Russia
For the first time statistical research for long-living microbursts () at decimetric wavelengths which were observed on the one-dimensional scans by the RATAN-600 radiotelescope in intensity and circular polarization with a sensitivity of about 5-10 Jy is carried out . The flux of microbursts is in the range 0.001-0.1 s.f.u., the degree of polarization is from 10% up to 100%, the duration of individual impulses - about 1-2 seconds. The microbursts and background sources exist for several days and appear at sites of prolonged energy release. Comparison of (); with noise storms at meter range of wavelengths (NS) is executed. Such analysis shows a high probability that (); are manifestation of NS at decimeter range of wavelengths. The possible reason of essential distinction of radio emission fluxes between (); and NS is analysed. Within the limits of common model of generation of radiowaves for (); and NS ! is shown that unlike type bursts I type (); are connected with noncoherent mechanism of generation of Langmuir waves. Radiation of (); is closer to continual radiation of NS, but because of high rate of pitch-angular diffusion it has a pulse character.