ELECTRON DYNAMICS AND WHISTLER WAVES AT QUASI-PERPENDICULAR SHOCKS

The collisionless, supercritical, quasi-perpendicular fast shock is in vestigated on sub-ion scales using an implicit, two-dimensional (2-D) full. particle code. For the first time, simulations are carried out w ith realistic characteristic frequencies and sufficiently high mass ra tio between the protons and electrons. As a result, there is relativel y little scattering of the electrons, i.e., they behave;largely adiaba tically as previously suggested based on spacecraft observations at th e Earth's bow shock. The large mass ratio also allows for a realistic description of the whistler mode dispersion. Phase-standing whistlers with propagation along the shock normal appear as transients. The domi nant whistlers found at late times in the simulations have upstream di rected group velocity but propagate at oblique direction between the s hock normal and the ambient magnetic field. Their properties match tho se of the ubiquitous observed upstream whistlers (''one-Hertz waves'') .