Magnetic Reconnection and Hot Spot Formation in Black Hole Accretion Disks

Understand

Hot spots, or plasmoids, forming due to magnetic reconnection in current sheets, are conjectured to power frequent X-ray and near-infrared flares from Sgr A*, the black hole in the center of our Galaxy.

• It is unclear how, where, and when current sheets form in black-hole accretion disks.
• We perform axisymmetric general-relativistic resistive magnetohydrodynamics simulations to model reconnection and plasmoid formation in a range of accretion flows.
• Current sheets and plasmoids are ubiquitous features which form regardless of the initial magnetic field in the disk, the magnetization in the quasi-steady-state phase of accretion, and the spin of the black hole.