[32] In the case when the surrounding medium is cold plasma, it is shown that the radiation occurs only when the proper frequency of the oscillator w0' exceeds the plasma frequency. The radiation spectra are similar to those in the case of vacuum if the plasma frequency is not too close to the proper frequency of the oscillator. If the both frequencies slightly differ from each other, at a high enough velocity the radiation spectrum lies completely in the region above w0'. The radiation power is a monotonously decreasing function of the velocity and plasma frequency.
[33] In the case when the medium has the dispersion of a resonant type, at some parameters of the problem the radiation spectrum consists of two separated frequency ranges, whereas at other parameters this two ranges are united into one range. The dependence of the radiation power on the source motion velocity is different at different relations between the resonance frequency, plasma frequency, and oscillator frequency. The comparison of the obtained results with the results for the corresponding problems in the case of nondispersive medium and cold plasma, shows that the presence of the resonant dispersion leads to different, much more complicated regularities characterizing the radiation of a moving oscillator.
[34] The expression for the radiation power is derived for the case when not only the dipole moves, but the surrounding it nondispersive medium moves as well, the motion velocities of the source and medium being parallel or antiparallel. It is noted that, in particular, at some parameters of the problem, the effect of the reversal of the wave losses sign takes place, that is the radiating power becomes negative. Unlike in the case of a moving charge, for an oscillator this effect can take place even in the regime of the "subluminal relative motion".
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