Numerical models of VHE emission by magnetic reconnection in X-ray binaries: GRMHD simulations and Monte Carlo cosmic-ray emission

• Published in: Proceedings of the International Astronomical Union 2018-08, Vol.14 (S346), p.388-393
• Main Authors: Rodríguez-Ramírez, J. C., de Gouveia Dal Pino, E. M., Alves Batista, R.
• Format: Article
• Language: English
• Subjects: Astronomy; Computational fluid dynamics; Computer simulation; Cosmic rays; Deposition; Emission analysis; Gas density; Mathematical models; Microquasars; Numerical models; Particle acceleration; Radiative transfer; Simulation; Turbulent flow; X ray binaries; X ray stars
• ISSN: 1743-9213; 1743-9221
• DOI: 10.1017/S1743921319001261

Galactic microquasars have been detected at very-high-energies (VHE) (> 100 GeV) and the particle acceleration mechanisms that produce this emission are not yet well-understood. Here we investigate a hadronic emission scenario where cosmic-rays (CRs) are accelerated in magnetic reconnection events by the turbulent, advected-dominated accretion flow (ADAF) believed to be present in the hard state of black hole binaries. We present Monte Carlo simulations of CR emission plus γ-γ and inverse Compton cascades, injecting CRs with a total energy consistent with the magnetic energy of the plasma. The background gas density, magnetic, and photon fields where CRs propagate and interact are modelled with general relativistic (GR), magneto-hydrodynamical simulations together with GR radiative transfer calculations. Our approach is applied to the microquasar Cygnus X-1, where we show a model configuration consistent with the VHE upper limits provided by MAGIC collaboration.