GeV emission and the Kerr black hole energy extraction in the BdHN I GRB 130427A

• Published in: The Astrophysical journal Vol. 886; no. 2
• Main Authors: Ruffini, R., Moradi, R., Rueda, J.A., Becerra, L., Bianco, C.L., Cherubini, C., Filippi, S., Chen, Y.C., Karlica, M., Sahakyan, N., Wang, Y., Xue, S.S.
• Format: Journal Article
• Language: English
• Published: American Astronomical Society 2019
• Subjects: Astrophysics; Physics; hypernova; magnetic field; p: acceleration; rotation; black hole: Kerr; AGN; cosmic radiation: UHE; gamma ray: burst
• ISSN: 0004-637X; 1538-4357
• DOI: 10.3847/1538-4357/ab4ce6

We propose that the "inner engine" of a type I binary-driven hypernova (BdHN) is composed of a Kerr black hole (BH) in a non-stationary state, embedded in a uniform magnetic field $B_0$ aligned with the BH rotation axis, and surrounded by an ionized plasma of extremely low density of $10^{-14}$~g~cm$^{-3}$. Using GRB 130427A as a prototype we show that this "inner engine" acts in a sequence of "elementary impulses". Electrons are accelerated to ultra-relativistic energy near the BH horizon and, propagating along the polar axis, $\theta =0$, they can reach energies of $\sim 10^{18}$ eV, and partially contribute to ultra-high energy cosmic rays (UHECRs). When propagating with ${\theta \neq 0}$ through the magnetic field $B_0$ they give origin by synchrotron emission to GeV and TeV radiation. The mass of BH, $M=2.3 M_\odot$, its spin, $\alpha = 0.47$, and the value of magnetic field $B_0= 3.48 \times 10^{10}$ G, are determined self-consistently in order to fulfill the energetic and the transparency requirement. The repetition time of each elementary impulse of energy ${\cal E} \sim 10^{37}$ erg, is $\sim 10^{-14}$ s at the beginning of the process, then slowly increasing with time evolution. In principle, this "\textit{inner engine}" can operate in a GRB for thousands of years. By scaling the BH mass and the magnetic field the same "inner engine" can describe active galactic nuclei (AGN).