High-frequency waves in solar and stellar coronae

On the basis of a numerical solution of dispersion equation we analyze characteristics of low-damping high-frequency waves in hot magnetized solar and stellar coronal plasmas in conditions when the electron gyrofrequency is equal or higher than the electron plasma frequency. It is shown that branches that correspond to Z-mode and ordinary waves approach each other when the magnetic field increases and become practically indistinguishable in a broad region of frequencies at all angles between the wave vector and the magnetic field. At angles between the wave vector and the magnetic field close to 90 degrees, a wave branch with an anomalous dispersion may occur. On the basis of the obtained results we suggest a new interpretation of such events in solar and stellar radio emission as broadband pulsations and spikes.