Radiative reconnection-powered TeV flares from the black hole magnetosphere in M87

Understand

Active Galactic Nuclei in general, and the supermassive black hole in M87 in particular, show bright and rapid gamma-ray flares up to energies of 100 GeV and above.

• For M87, the flares show multiwavelength components, and the variability timescale is comparable to the dynamical time of the event horizon, suggesting that the emission may come from a compact region nearby the nucleus.
• However, the emission mechanism for these flares is not well understood.
• Recent high-resolution general-relativistic magnetohydrodynamic simulations show the occurrence of episodic magnetic reconnection events that can power flares nearby the black hole event horizon.