On the origin of fast radio bursts (FRBs)

Understand

We derive stringent constraints on the persistent source associated with FRB 121102: Size $10^{17}$ cm $<R<10^{18}$ cm, age $<300$ yr, characteristic electron energy $\varepsilon_e\sim0.3$ GeV, total energy $\sim10^{49}$ erg.

• The hot radiating plasma is confined by a cold plasma of mass $M_c<0.03 (R/10^{17.5}{\rm cm})^4 M_\odot$.
• The source is nearly resolved, and may be resolved by 10 GHz observations.
• The fact that $\varepsilon_e\sim m_p c^2$ suggests that the hot plasma was created by the ejection of a mildly relativistic, $M\sim10^{-5} M_\odot$ shell, which propagated into an extended ambient medium or collided with a pre-ejected shell of mass $M_c$.