CME-associated Radio Spectrum Observed at 1-2.5 GHz

J.R. Cecatto

DAS-INPE, Brazil

We know Coronal Mass Ejections (CME) and flares are the most energetic phenomena happening on the Sun. Until now the information about origin and trigger mechanism of CME remains scarce. Also, there is unconclusive information about the association between them and flares although progress has been made in recent years. Multi-spectral observations suggested that the flare energy release occurs in regions from where the decimetric radio emission originates. In this case, investigations of the solar radio emission in this wavelength range can give us valuable information about these questions. During last solar maximum the Brazilian Solar Spectroscope (BSS) observed the solar radio spectrum (1-2.5 GHz) with high time (100-20 ms) and frequency (50-100 channels) resolutions on a daily (11-19 UT) basis. During the period 1999-2002, a significant fraction (~ 20%) of CME recorded by LASCO experiment on board SOHO has showed an associated activity recorded by BSS. An analysis of the decimetric radio spectrum associated to CME showed a dominance of continuum and/or pulsations. This association becomes stronger when we consider the CME acceleration since its origin on the Sun. We present a model of this association between CME dynamics and the decimetric radio activity recorded by BSS. Also, the characteristics of decimetric radio emission measured in association to CME occurrence are presented.