Some aspects of electrostatic waves in space plasmas

Many satellite-based experiments show evidence of electrostatic waves in space. Space plasmas are often not in thermal equilibrium, and hence the distribution function is non-Maxwellian, a superthermal "tail" being commonly observed. Nonetheless, the kinetic theory of waves in space plasmas is often based on a Maxwellian distribution. We model the distribution function with the aid of a generalized Lorentzian ("kappa") distribution, which allows for a variety of possible superthermal tails. We demonstrate the effects of these energetic particles on the characteristics of the electrostatic waves observed in space plasmas.