Oral Presentation

Magnetospheric gamma radiation from rotating black holes

Author(s): Kouichi Hirotani

Presenter: Kouichi Hirotani (ASIAA)

The MAGIC telescopes reported on gamma-ray observations of the radio galaxy IC 310, which presumably harbors a super-massive black hole (BH). MAGIC detected a powerful flare in VHE between 70 GeV and 8 TeV and revealed that the flickering flares originated from a compact region that is smaller than the horizon radius (Aleksic et al. 2014, Science 346, 1080). To interpret this amazing finding of a unique sub-horizon phenomenon, we applied the pulsar outer magnetospheric accelerator theory to the BH magnetosphere of IC 310. Assuming that the magnetic field is as strong as 1 T, we demonstrate that the observed VHE flux can be reproduced by this model. We also apply the model to the base of the M87 jet and show that horizon-scale emission should be detectable in VHE gamma-ray energies (as flares) and that the VHE flux anti-correlate with the ADAF submillimeter flux. We therefore propose simultaneous observations at submillimeter wavelength and VHE to discriminate the VHE emissions from the shock-in-jet model and the present black-hole gap model.