Pulsar Wind Bubble
| 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) | Pulsar Wind Bubble (NS and MWD) | Single | -- | Synch. | Yes | -- | -- | -- | -- | Yes | -- | -- | -- | http://adsabs.harvard.edu/abs/2017MNRAS.467.3542M | None |
Definitions: LF Radio (3 MHz to 3 GHz); HF Radio (3 GHz to 30 GHz); Microwave (30 to 300 GHz)
Model Description
Consider a pulsar (NS or magnetic WD, hereafter MWD) within a nebula. The dissipation of spin energy drives a wind of relativistic electron-positron plasma-a pulsar wind nebula (PWN)-observable as a shell around the NS. Where the plasma wind ceases is called the termination shock. Here the plasma decelerates to sub-relativistic speeds and forms a wind bubble around the pulsar. A subsequent outburst, possibly triggered by pulsar spin-down or by magnetic dissipation in the magnetosphere, will rapidly decelerate when it impacts the PWN, triggering a GRB. Energy that is not radiated away by the explosion itself travels outwards at a relativistic speed, causing a highly relativistic shock wave to propagates forward into space. Synchrotron emission is generated, however the coherence mechanism to generate FRBs at this point is unknown. A synchrotron maser might result from the coherently reflected particles in the shock front, but for NSs and magnetic MWDs the frequency is likely too low to be consistent with FRBs. A reverse shock wave may give rise to afterglow, however both this afterglow and the GRB formed at the shock front are not expected to be observable.
Observational Constraints
Emission from the PWN as it expands outwards might be detected in the NS scenario. A SN a few years prior to the FRB may be observed for either body.