WD-WD Merger
| 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 | |||||||
| Merger | WD-WD | Single | Mag. reconnection | Curv. | Yes | -- | -- | -- | supernova | afterglow | -- | -- | -- | http://adsabs.harvard.edu/abs/2013ApJ...776L..39K | -- |
Definitions: LF Radio (3 MHz to 3 GHz); HF Radio (3 GHz to 30 GHz); Microwave (30 to 300 GHz)
Model Description
It has been proposed that FRBs may form when a doubly-degenerate binary WD merger forms a rapidly rotating, magnetized, massive WD. The event rate of such a scenario is consistent with that predicted for FRBs. The rapid rotation of the WD merger transports, via convection, inner magnetic fields to the polar regions, which greatly enhances the magnetic field strength. The corresponding energy budget has been shown to be sufficient for FRB production. In the polar regions, where the magnetic fields are twisted by differential rotation or magnetic instabilities, reconnection is triggered, and electron bunches are injected into the polar region in a timescale comparable with FRBs. The electrons are accelerated to relativistic speeds along magnetic field lines, creating curvature radiation. WDs transfer angular momentum into the surrounding debris disk, rapidly reducing their rotation speed and hampering multiple FRB events. The FRBs are predicted to have one of two possible counter parts: X-ray emission, or a Type Ia supernova (SN) formed upon the collapse of the massive WD.