Axion Star and BH
| 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 | |||||||
| Collision / Interaction | Axion Star and BH | Repeat | Electron oscillation | -- | Yes (Circular Polarization) | -- | -- | -- | -- | -- | -- | -- | -- | https://arxiv.org/pdf/1707.04827.pdf | |
Definitions: LF Radio (3 MHz to 3 GHz); HF Radio (3 GHz to 30 GHz); Microwave (30 to 300 GHz)
Model Description
If an axion star were captured by a BH with a strongly magnetized accretion disk, the axion star’s orbit will lead it to approach and impact the accretion disk several times at different locations. The electric field induced by the axion star passing through a strong magnetic field will result in the coherent oscillation of surrounding electrons.
Observational Constraints
The frequency of the radiation will depend on the velocity of the accretion disk at the point of impact. In this way, the variation in central burst frequencies of FRB 121102 can be explained. The intrinsic emission frequency is finite, FRBs would be circularly polarized, and no counterparts are expected.