A gyro-synchrotron maser in the solar corona?

It is found that a gyrosynchrotron maser is a possible interpretation of observed high brightness temperatures (10 to the 10th K) in some moving Type IV bursts. However, unless considerably higher brightness temperatures at lower frequencies are found, it appears that nonamplified emission from electrons with energies (about 1 MeV) higher than considered in the past is a more plausible interpretation (Stewart et al., 1978). If the brightness temperature at lower frequencies is found to be much higher (e.g., 10 to the 12th K at 20 MHz), this would provide evidence in favor of the maser mechanism.