Decametric Radiations from a Large Scale Magnetic Loop in the Solar Corona

Abstract

Rising tone bursts whose frequencies are drifting in decametric wavelength range (20–40 MHz) are sometimes observed associated with strong flares; the studies on these bursts have been made for the case of flare event on February 6, 1986 by analyzing dynamic spectra obtained at the Tsukidate observatory, in relation to the configuration of coronal magnetic field. The present analyses for the frequency drift of decametric radiation suggest the motion of energetic particles along the special form of the magnetic loop and its origin and evolution. That is, a large scale isolatedly closed magnetic loop is formed by magnetic reconnection and is pushed out with a speed of 400–500 km/s toward outer coronal region.