Langmuir waves, type III radio bursts and impulsive electron events

Abstract

It is known that interplanetary electron beams ejected from the sun are unstable in the solar wind and that they generate Langmuir waves (electrostatic) and electromagnetic waves (type III bursts). For the present statistical analysis we used radio observations in a range of 4-256 kHz from WAVES experiment onboard WIND spacecraft. A subset of 36 events, with Langmuir waves and type III radio bursts occurring at the same time, was selected. After background was removed, the remaining power spectral density is modeled by Pearson's system of probability distributions (type I, type IV and type VI). A relation in form of power-law between the power of Langmuir waves, the energy and the flux of the electrons in the impulsive electron events corresponding to the occurrence of the Langmuir waves is preliminary examined. We found a strong power-law dependence between electron fluxes and energies (power-law index γ equals 2.47 ± 0.06). The consequence of this fact is that the estimated parameters are highly unstable in numerical sense, thus the proposed model can be simplified, instead of two variables, it can be represented with only one: flux or energy.