A MODEL OF SVC RADIATION IN MAGNETIC DIPOLE FIELD AND RADIATION VARYING WITH MAGNETIC FIELD(Ⅱ)——SVC RADIATION MECHANISM AND RADIATION VARIATION WITH MAGNETIC FIELD

摘要

In our model, the latest EUV data on the chromosphere-corona transition region havebeen used. We have assumed that the plasma conditions above an active region are varyingcontinuously from the centre of tbe region to the adjacent quiet region. We take the threephysical parameters of the plasma (electron temperature and density, and magnetic field) asfunctions of both the beight above the photosphere and the distance from the central axis ofthe active region. According to the combined mechanism including both the gyroresonanceradiation and the bremsstrahlung, using a dipole magnetic field and above-mentioned modelof the electron temperature and density, we calculated the radio radiation of the slowly varyingcomponent (SVC) and emphatically studied the radiative characteristics of the SVC radiation(such as the spectra of flux density, polarization degree, and brightness temperature, and thebrightness distribution) and the geometrical features of the SVC radiation source (such as theheight and radius), and their variations with the magnetic field. Some very interesting resultshave been obtained and they are in considerably good agreement with observations.