Statistical Survey of Type III Radio Bursts at Long Wavelengths Observed by the Solar TErrestrial RElations Observatory (STEREO)/Waves Instruments: Radio Flux Density Variations with Frequency

摘要

We have performed a statistical study of $152$ Type III radio bursts observedby Solar TErrestrial RElations Observatory (STEREO)/Waves between May 2007 andFebruary 2013. We have investigated the flux density between $125$kHz and$16$MHz. Both high- and low-frequency cutoffs have been observed in $60\,%$ ofevents suggesting an important role of propagation. As already reported byprevious authors, we observed that the maximum flux density occurs at $1$MHz onboth spacecraft. We have developed a simplified analytical model of the fluxdensity as a function of radial distance and compared it to the STEREO/Wavesdata.