Capture of a Red Giant by the Black Hole Sagittarius A* as a Possible Origin for the TeV Gamma Rays from the Galactic Center

Abstract

Non-thermal TeV $\gamma$-ray emission within a multiparsec has been observed from the center region of our Galaxy. We argue that these $\gamma$-rays are the result of transient activity of the massive black hole Sgr A${}^{\ast }$ that resides at the Galactic Center. Several thousand years ago, the black hole may have experienced an active phase by capturing a red giant star and forming an accretion disk, temporarily behaving like an active galactic nucleus. A powerful jet, which contains plenty of high speed protons, was launched during the process. These runaway protons interact with the dense ambient medium, producing TeV $\gamma$-ray emission through the ${\pi }^0$-decay process. We show that the total energy deposited in this way is large enough to account for observations. The diffusion length of protons is also consistent with the observed size of the TeV source.

15 pages, 1 figure, Accepted to ApJ

References in corpus (12)

• Very high energy gamma rays from the direction of Sagittarius A*
• Calibration of cameras of the H.E.S.S. detector
• The distribution and cosmic evolution of massive black hole spins
• A dark jet dominates the power output of the stellar black hole Cygnus X-1
• High energy gamma rays from the massive black hole in the Galactic Center
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• TeV Emission from the Galactic Center Black-Hole Plerion
• Electromagnetic radiation initiated by hadronic jets from microquasars in the ISM
• TeV $\gamma$-radiation from Dark Matter annihilation in the Galactic center
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Cited by in corpus (8)

• Inverse Compton Scenarios for the TeV Gamma-Ray Emission of the Galactic Centre
• Annihilation Emission from the Galactic Black Hole
• Diffuse Gamma-ray Emission from the Galactic Center - A Multiple Energy Injection Model
• A tidal disruption model for the gamma-ray burst of GRB 060614
• Transient X-ray Emission from Normal Galactic Nuclei
• Astrophysics in 2006
• Reduced spin-down rate of PSR J0738-4042 explained as due to an asteroid disruption event
• Study on the spectrum of the injected relativistic protons