Radio emission spectrum from an interplanetary shock front

The characteristics of low-damping high-frequency waves in hot magnetized solar and stellar coronal plasmas under the conditions when the electron gyrofrequency ω_He is equal to or higher than the electron plasma frequency ω_pe have been analyzed using the numerical solution of the dispersion equation. It is shown that the wave branches corresponding to the Z mode and ordinary waves approach each other when the magnetic field increases and become almost indistinguishable in a wide frequency range at all angles between the wave vector and magnetic field. A branch with anomalous dispersion appears at angles close to 90°. A new interpretation of broadband pulsations and spikes is suggested on the basis of the results.