Black hole flares: ejection of accreted magnetic flux through 3D plasmoid-mediated reconnection

Understand

Magnetic reconnection can power bright, rapid flares originating from the inner magnetosphere of accreting black holes.

• We conduct extremely high resolution ($5376\times2304\times2304$ cells) general-relativistic magnetohydrodynamics simulations, capturing plasmoid-mediated reconnection in a 3D magnetically arrested disk for the first time.
• We show that an equatorial, plasmoid-unstable current sheet forms in a transient, non-axisymmetric, low-density magnetosphere within the inner few Schwarzschild radii.
• Magnetic flux bundles escape from the event horizon through reconnection at the universal plasmoid-mediated rate in this current sheet.