ACCELERATION ON A GALACTIC SCALE,
STANFORD UNIV CALIF INST FOR PLASMA RESEARCH
Pagination or Media Count:
Observations of radio galaxies and of radio emission from quasars provide evidence for particle acceleration on a galactic scale. The acceleration is typically associated with some kind of explosion, i.e., with an instability. It appears, therefore, that galactic acceleration is part of a spontaneous process occurring in a closed system of galactic dimensions. An analogous process on a laboratory scale is provided by certain plasma experiments, in which a quiescent plasma exhibits a sudden explosive instability which in turn leads to acceleration of some particles to high energies. This comparison leads to the suggestion that a galactic explosion which leads to particle acceleration is typically a plasma instability. Various forms are suggested for the magnetic-field configuration to be associated with a newly condensed object with the mass of a galactic nucleus, tentatively identified as a quasar, and an evolved radio galaxy. The energy content of such configurations is estimated, and shown to be adequate to explain observed radio clouds. Discussion of a radio outburst of 3C 273 leads to the view that some of the radio emission from quasars is the result of collective plasma processes. Hence such outbursts provide direct evidence for the occurrence of plasma instabilities on a galactic scale.
- Plasma Physics and Magnetohydrodynamics