Synchronous Brightenings Of Microwave Emission Of Solar Active Regions According To The RATAN-600 Spectral Data

Extract

This paper is devoted to the investigation of the synchronous enhancements of the solar source fluxes according to the RATAN-600 Southern Sector observations at the 1.92 cm, 2.24 cm, 2.74 cm, and 3.21 cm radio waves. The observations were carried out on 11.09.01 from 8:30 UT to 10:30 UT every 8 min. We use the term “synchronous bursts” or “synchronous brightenings” instead of the “sympathetic bursts” as the time resolution of the RATAN - 600 is not high. The solar source brightenings are synchronous if they are registered in 2 - 2.5 min time lag, i.e. in the time interval of passage of the Sun through the central part of the main lobe of the antenna power pattern. The high flux sensitivity of the radio telescope - radiometer system was 0.005 s.f.u. The solar sources were identified with the active regions: AR 9610, AR 9608, AR 9606, AR 9616, AR 9617, which widely separated from each other (up to $10^{6}$ km). According to our observations, the synchronous enhancements were observed at the moments of the soft X ray brightenings and X ray bursts (Figure 1a). The temporal variations of the relative fluxes of the solar sources $F/F_{0}$ were compared to the $X$-ray (GOES 8,10; $H_{\alpha}$ - flares and to the radio bursts at 9100 MHz, $F_{0}$ - the radio emission flux from the “quiet” Sun, $F$ - the radio emission flux from the solar source). It turned out that the interrelationships of the active regions AR 9610, AR 9608, AR 9606 were the most interesting. It was registered 4 synchronous brightenings of solar sources AR 9610, AR 9608 at the moment of the observations: 8:38 UT, 9:02 UT, 9:50 UT, 10:30 UT. We recorded synchronous brightenings of solar sources at 1.92 cm, 2.24 cm, 2.74 cm, and 3.21 cm radio waves: at $\lambda=2.24 cm$ – $\Delta(F)=(0.24 \div 0.88)$ s.f.u. and at $\lambda=3.21$ cm – $\Delta(F)=(0.21 \div 0.94)$ s.f.u. The detailed halo solar source is the magnetosphere, which was identified with all extensive AR 9608 region excepting the primary the most strong solar source of the active region radio emission. The angular size of halo is closed to the angular size of AR 9608 ($7.7 \arcmin$). The comparison of the brightening onset of the AR 9610, AR 9608 interacting active regions in the time interval (9:26 - 9:58 UT) and the discovered forestalling of the halo flux quick intensification at $\lambda=2.24$ cm and $\lambda=3.21$ cm pointed to the active process start in the AR 9608 solar source at $\lambda=3.21$ cm. As it was shown, the dynamics of the time intensity variation of solar sources at $\lambda=3.21$ cm, $\lambda$=2.74 cm is more complicated. It is demonstrated by against of the synchronous of the moments of the AR 9610 relative flux maxima with the $\lambda$ increase (Figure 1b).To search for other articles by the author(s) go to: http://adsabs.harvard.edu/abstract_service.html