Radio Emission by Soliton Formation in Relativistically Hot Streaming Pulsar Pair Plasmas

A number of possible pulsar radio emission mechanisms are based on streaming instabilities in relativistically hot electron-positron pair plasmas. At saturation the unstable waves can form, principle, stable solitary which could emit observed intense signals. We searched for proper plasma parameters would lead to formation solitons, investigated their properties and dynamics as well resulting oscillations electrons positrons possibly leading wave emission. utilized a one-dimensional version relativistic Particle-in-Cell code ACRONYM initialized with an appropriately parameterized Maxwell-J\"uttner velocity space particle distribution study evolution instability plasma. found that strong electrostatic superluminal L-mode solitons formed plasmas normalized inverse temperatures $\rho \geq 1.66$ or relative beam drift speeds Lorentz factors $\gamma > 40$. The fulfill conditions. For appropriate energy densities reach up $1.1 \times 10^5$ erg$\cdot$cm$^{-3}$, while those subluminal only $1.2 10^4$ erg$\cdot$cm$^{-3}$. Estimated $7 10^{12}$ erg$\cdot$cm$^{-3}$ suffice explain nanoshots.