FRB Sky Distribution, Rarity, Energetics, Magnetic Reconnection and Sources. (arXiv:1811.10755v1 [astro-ph.HE])
<a href="http://arxiv.org/find/astro-ph/1/au:+Katz_J/0/1/0/all/0/1">J. I. Katz</a>
The isotropic distribution of FRB on the sky, differing from that of
starlight, indicates either that they are not associated with a stellar
population or that they are rare events with a large characteristic energy
scale; there are no Galactic nano-FRB. FRB may be emitted by relativistic
particles accelerated by magnetic reconnection in low density plasma. If the
particles or charge `bunches’ are collimated and have Lorentz factor $gamma$,
their radiation is collimated into a solid angle $sim gamma^{-2}$ sterad,
reducing FRB energy requirements. If powered by magnetic reconnection, a pulse
of length $Delta t$ may draw on the magnetic energy in a volume $sim gamma^4
(c Delta t)^3$, although only a fraction $sim 1/gamma^2$ of this may be
dissipated without decollimating the beam. The absence of periodicity argues
that repeating FRB are not produced by neutron stars; I suggest their origin in
the relativistic jets of AGN. The absence of any repetition in extensive
monitoring of non-repeating FRB points to an origin in catastrophic events such
as the collapse of accreting magnetic neutron stars to black holes, when their
disappearing magnetic moments induce a large EMF in nearby matter. Magnetic
reconnection may also account for the energetics of pulsar nanoshots.
The isotropic distribution of FRB on the sky, differing from that of
starlight, indicates either that they are not associated with a stellar
population or that they are rare events with a large characteristic energy
scale; there are no Galactic nano-FRB. FRB may be emitted by relativistic
particles accelerated by magnetic reconnection in low density plasma. If the
particles or charge `bunches’ are collimated and have Lorentz factor $gamma$,
their radiation is collimated into a solid angle $sim gamma^{-2}$ sterad,
reducing FRB energy requirements. If powered by magnetic reconnection, a pulse
of length $Delta t$ may draw on the magnetic energy in a volume $sim gamma^4
(c Delta t)^3$, although only a fraction $sim 1/gamma^2$ of this may be
dissipated without decollimating the beam. The absence of periodicity argues
that repeating FRB are not produced by neutron stars; I suggest their origin in
the relativistic jets of AGN. The absence of any repetition in extensive
monitoring of non-repeating FRB points to an origin in catastrophic events such
as the collapse of accreting magnetic neutron stars to black holes, when their
disappearing magnetic moments induce a large EMF in nearby matter. Magnetic
reconnection may also account for the energetics of pulsar nanoshots.
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