Giant Pulses

From FRB Theory Wiki
Jump to: navigation, search





Summary Table
Category Progenitor Type Energy Mechanism Emission Mechanism Counterparts References Brief Comments
LF Radio HF Radio Microwave Terahertz Optical/IR X-rays Gamma-rays Gravitational Waves Neutrinos
SNR (Pulsars) Giant Pulses Repeat -- Synch.
/ Curv.
Yes -- -- -- -- -- -- -- -- http://adsabs.harvard.edu/abs/2012MNRAS.425L..71K, http://adsabs.harvard.edu/abs/2016MNRAS.457..232C, https://arxiv.org/pdf/1505.05535.pdf Rapid flux decay expected to be observed within a few years.

Definitions: LF Radio (3 MHz to 3 GHz); HF Radio (3 GHz to 30 GHz); Microwave (30 to 300 GHz)


Model Description

Analogous to models for the Crab pulsar, FRBs of extragalactic origins may be giant pulses of a young pulsar. A specific giant pulse mechanism has been proposed for FRBs, in which a nearly charge-neutral clump of particles (produced by a two-streaming instability or a bunching instability) is accelerated through the pulsar magnetosphere by some reconnection event. The resultant coherent curvature radiation will be emitted for the duration that the clump remains intact. Note, however, that the emission mechanism of giant pulses remains an open question, and that this represents one possibility for FRB formation.

Observational Constraints

FRBs are predicted to be repeating and stochastic. A SN explosion a few years prior to the FRB may be observable. The DM, RM and polarization of FRBs in this scenario are owed to the nebula surrounding the pulsar as opposed to the intergalactic medium. This places FRBs at extragalactic (as opposed to cosmological) distances, and thus relaxes the energy requirements. The spin-down luminosity decreases within a timescale of a few years. The giant pulse model therefore depends on the observation of rapid flux decay in FRBs within a few years.