GW150914-like Black Holes as Galactic High-Energy Sources

Understand

The first direct detections of gravitational waves (GWs) from black hole (BH) mergers, GW150914, GW151226 and LVT151012, give a robust lower limit $\sim 70000$ on the number of merged, highly-spinning BHs in our Galaxy.

• The total spin energy is comparable to all the kinetic energy of supernovae that ever happened in our Galaxy.
• The BHs release the spin energy to relativistic jets by accreting matter and magnetic fields from the interstellar medium (ISM).
• By considering the distributions of the ISM density, BH mass and velocity, we calculate the luminosity function of the BH jets, and find that they can potentially accelerate TeV-PeV cosmic-ray particles in our Galaxy with total power $\sim 10^{37\pm 3}$ erg s$^{-1}$ as PeVatrons, positron factories and/or unidentified TeV gamma-ray sources.