The necessity of fundamental emission in type III bursts

Observations of some type III radio bursts in the hectometer and kilometer wave range are compared with theoretical predictions. It is shown that the burst emission must be near the plasma frequency in the region between 10 R _⊙ and 50 R _⊙ in order to be consistent with the observed steep rise in brightness temperature for these bursts. The results of Fainberg, Malitson et al., and Haddock and Alvarez are discussed and compared with the interpretation of emission near the plasma frequency.