Stability of Contact Discontinuities in Electrostatic Hybrid- and Full-Vlasov Simulations

The stability of contact discontinuities was studied by means of one-dimensional electrostatic (ES) hybrid- and full-Vlasov simulations with the initial parameter based on observational data. The ES hybrid-Vlasov simulations show that the sharp gradient of the ion number density is generated at the early stage and is subsequently maintained for a long term. On the other hand, the sharp gradient is absent in the ES full-Vlasov simulation. The generalized Ohm's law shows that the electron pressure gradient accounts for the electric field on the ion time scale in both ES hybrid- and full-Vlasov simulations. It is shown that there is a difference in the time evolution of the electron pressure between the ES hybrid- and full-Vlasov simulations, which is mainly caused by the electron heat flux.