http://arxiv.org/abs/1512.04503
The high brightness of Fast Radio Bursts requires coherent emission by particles “bunched” by plasma instability at powers far in excess of those of pulsar spindown. Dissipation of magnetic energy in a neutron star magnetosphere, as in popular models of Soft Gamma Repeaters, can meet the energy requirement and produces an electron-positron pair plasma. Annihilation gamma rays are scattered by cooler plasma, producing a broad beam of electrons. The resulting electron distribution function is unstable to the “bump-on-tail” plasma instability. Electron plasma waves grow exponentially, scattering on density gradients to produce propagating electromagnetic waves, in analogy to Solar Type III Radio Bursts. Galactic SGR may make Galactic FRB, many orders of magnitude brighter than FRB at “cosmological” distances, that could be observed by radio telescopes out of beam or by modest arrays of dipole antennas.
J. Katz
Tue, 15 Dec 15
1/87
Comments: 10 pp. 1 fig
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