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 | Open Question | Synch. | Yes | -- | -- | -- | -- | ULXs | -- | -- | -- | http://adsabs.harvard.edu/abs/2017MNRAS.467.3542M | 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. |
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.