AAS 200th meeting, Albuquerque, NM, June 2002
Session 80. Neutron Stars, Relativity, MHO
Oral, Thursday, June 6, 2002, 10:00-11:30am, San Miguel

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[80.05] A Magnetic Model for AGN engines

P. N. Arendt, I. G. Avramidi (New Mexico Tech)

Standard quantum field theory predicts suppressing the effective mass of electrons, possibly to zero, in ultrastrong magnetic fields. The required field strength, several orders of magnitude above B\mathrm QED, is expected to occur in the cores of some magnetars, and in the final stages of a collapsar as it forms a black hole. Tachyon emission will then occur, the physical end result of which will be two oppositely-directed jets of ordinary matter and antimatter.

We will show that this mechanism provides a natural trigger for the sudden conversion of electromagnetic energy into a GRB, and that a beamed `fireball' is to be expected from such an event. The mechanism, if correct, also explains the similarity of SGR and GRB spectra, despite the vast difference in scales of the two phenomena. It will further be shown that a long-lived magnetic remnant is to be expected following a collapsar-induced GRB, which will continue to produce oppositely-directed jets of emission over large scales for some time, which allows the central engine to efficiently shed angular momentum and excess magnetic field during the steady AGN phase. Unlike the Blandford-Znajek mechanism, which relies upon the formation of extremely strong electric fields to operate, this mechanism relies only upon strong magnetic fields, which are to be expected much more generically in astrophysical situations.

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Bulletin of the American Astronomical Society, 34
© 2002. The American Astronomical Soceity.