Turbulent fast magnetic reconnection around accretion disk systems: from analytical to numerical studies

Data: 
24/10/2018 - 14:00 - 15:00
Local: 
Auditório "Prof. Dr. Paulo Benevides Soares", Bloco G

Turbulent fast magnetic reconnection around accretion disk systems: from analytical to numerical studies

Luis Henrique Sinki Kadowaki

IAG/USP

Fast magnetic reconnection is a crucial mechanism for understanding particle acceleration and very high-energy (gamma and neutrino) emission in magnetized systems in general. A potential model to explain the transition between the High/Soft and Low/Hard X-ray states observed in black hole binaries (BHBs) and Active Galactic Nuclei (AGNs) can be attributed to fast magnetic reconnection induced in the turbulent corona of accretion disks. According to this model, the power released by fast reconnection between the magnetic field lines arising from the inner accretion disk and the lines anchored into the compact source could accelerate relativistic particles in a first-order Fermi process and produce the observed non-thermal high-energy emission.

 In this talk, we will summarize the main insights of our fast magnetic reconnection analytical model and discuss the results of our recent local magnetohydrodynamic (MHD) and global general-relativistic MHD (GRMHD) simulations of accretion disks around black holes, where turbulence is naturally driven by MHD instabilities, such as the magnetorotational instability (MRI) and the Parker-Rayleigh-Taylor instability (PRTI). We will also present studies of magnetic reconnection driven by kink instabilities inside jets employing special relativistic MHD (SRMHD) simulations. Finally, we will present a detailed statistical analysis to identify the presence of fast magnetic reconnection in the turbulent regions of these numerical models. We have determined the magnetic reconnection rates in these systems obtaining averaged reconnection rates comparable with the predictions of the theory of turbulence-induced fast reconnection.