Effects of positron density and temperature on ion-acoustic solitary waves in a magnetized electron-positron-ion plasma: Oblique propagation

Ion-acoustic (IA) solitary waves are investigated in a magnetized three-component plasma consisting of cold ions, isothermal hot electrons, and positrons. The basic set of fluid equations is reduced to the Korteweg de Vries equation using the standard reductive perturbation (multiple-scale) technique. Theoretical and numerical analyses confirm significant effects of the presence of positrons and the dependence of the electron to positron temperature ratio on the amplitude and the width of IA solitary waves. It is shown that the rarefactive and compressive IA solitary excitations can propagate when the propagation angle θ satisfies 0≤θ<π/2 and π/2<θ≤π, respectively. Also, it is remarked that the amplitude of the rarefactive and compressive IA solitary excitations is not affected by the magnitude of external magnetic field B0, whereas their width depends strictly on B0. The numerical analysis has been done based on the typical numerical data from a pulsar magnetosphere.