Ion acoustic solitary waves in a plasma with nonthermal electrons featuring Tsallis distribution

The model of Cairns et al. [Geophys. Res. Lett. 22, 2709 (1995)] is generalized. A physically meaningful nonextensive nonthermal velocity distribution is outlined. As the nonextensive character of the nonthermal electrons increases, the distribution shoulders may become less or more prominent and high-energy states are less or more probable than in the extensive nonthermal case. It is found that our plasma model supports the coexistence of smooth rarefactive and spiky compressive ion-acoustic solitary waves. The rarefactive solitons are more affected by nonextensivity than their compressive counterpart and a slight increase in the nonextensive parameter may destroy this dual nature.