On the microwave oscillations from active region NOAA 0139

Abstract

This investigation is devoted to the study of time variations and spatial peculiarities of radio local radio sources associated with the solar active regions (AR) on the basis of microwave observations in September–October 2002. During this period the most interesting results have been obtained for the AR NOAA 0139. So, in this paper an analysis of this radio source is presented. The observations were made with the radio telescopes RT–22 (Crimea), RATAN–600, the Siberian Solar Radio Telescope (SSRT) and Nobeyama. Observations with the RT–22 (wavelengths 2.0, 2.3, 3.5 cm) were carried out by the quasi–zero method with the flux sensitivity of 0.1 s.f.u and the temporal resolution of about 0.1 s. The typical length of realization was about 6.5 hours. The spatial resolution of few arc minutes allowed to limit the analysis by the particular AR but was not enough to distinguish any details. Nevertheless spectral analysis of the AR made using observations with high one–dimensional resolution of the RATAN–600 shows that at short cm wavelengths for this AR at the period of the RT–22 observations dominated thermal cyclotron emission of above the largest sunspot of the group. This result was also confirmed by radio maps of the Nobeyama at wavelength 1.76 cm.To search for other articles by the author(s) go to: http://adsabs.harvard.edu/abstract_service.html