Scattering of radiation in plasma
Until now, emission and absorption processes (including negative reabsorption in non-equilibrium plasma) have been considered as the main factors affecting transfer of radiation in astrophysical plasmas. Emission or absorption of photons or plasmons by charged plasma particles have been the basic processes of interaction of radiation with plasma in this case. There are however other processes which can significantly affect radiation transfer in plasmas. We refer to scattering by waves and particles which photon-photon or photon-particle collisions contribute to. In some cases these processes can radically transform angular and frequency spectra of radiation and also lead to the conversion (transformation) of radiation from one mode to another. The latter is especially important for plasma mechanisms of radio emission which can only act effectively if energy is transferred from the excited plasma waves into electromagnetic radiation capable of escaping the plasma (see section 3.2). Resonant cyclotron scattering leads to the formation of absorption features in spectra of magnetic degenerate stars. Inverse influence of radiation onto plasma leads to radiation pressure force. In some cases this force which originates due to strong cyclotron scattering exceeds the gravitational one and drives plasma ejection from magnetic degenerate stars. The ejected matter can accumulate in magnetospheres of these objects and form extended plasma envelopes around them.
KeywordsNeutron Star Optical Depth Transfer Equation Plasma Wave White Dwarf
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