Lightning black holes as unidentified TeV sources

  • Kouichi HirotaniEmail author
  • Hung-Yi Pu
  • Satoki Matsushita


Imaging Atmospheric Cherenkov Telescopes have revealed more than 100 TeV sources along the galactic plane, around 45% of them remain unidentified. However, radio observations revealed that dense molecular clumps are associated with 67% of 18 unidentified TeV sources. In this paper, we propose that an electron–positron magnetospheric accelerator emits detectable TeV gamma-rays when a rapidly rotating black hole enters a gaseous cloud. Since the general-relativistic effect plays an essential role in this magnetospheric lepton accelerator scenario, the emissions take place in the direct vicinity of the event horizon, resulting in a point-like gamma-ray image. We demonstrate that their gamma-ray spectra have two peaks around 0.1 GeV and 0.1 TeV and that the accelerators become most luminous when the mass accretion rate becomes about 0.01% of the Eddington accretion rate. We compare the results with alternative scenarios such as the cosmic-ray hadron scenario, which predicts an extended morphology of the gamma-ray image with a single power-law photon spectrum from GeV to 100 TeV.


Black hole physics gamma-rays magnetic fields 


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Copyright information

© Indian Academy of Sciences 2018

Authors and Affiliations

  • Kouichi Hirotani
    • 1
    Email author
  • Hung-Yi Pu
    • 2
  • Satoki Matsushita
    • 1
  1. 1.Academia Sinica Institute of Astronomy and AstrophysicsTaipeiTaiwan, Republic of China
  2. 2.Perimeter Institute for Theoretical PhysicsWaterlooCanada

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