Magnetically Modified Spherical Accretion in GRMHD: Reconnection-Driven Convection and Jet Propagation

Abstract

We present 3D general relativistic magnetohydrodynamic(GRMHD) simulations of zero angular momentum accretion around a rapidly rotating black hole, modified by the presence of initially uniform magnetic fields. We consider serveral angles between the magnetic field direction and the black hole spin. In the resulting flows, the midplane dynamics are governed by magnetic reconnection-driven turbulence in a magnetically arrested (or a nearly arrested) state. Electromagnetic jets with outflow efficiencies ~10-200% occupy the polar regions, reaching several hundred gravitational radii before they dissipate due to the kink instability. The jet directions fluctuate in time and can be tilted by as much as ~30 degrees with respect to black hole spin, but this tilt does not depend strongly on the tilt of the initial magnetic field. A jet forms even when there is no initial net vertical magnetic flux since turbulent, horizon-scale fluctuations can generate a net vertical field locally. Peak jet power is obtained for an initial magnetic field tilted by 40-80 degrees with respect to the black hole spin because this maximizes the amount of magnetic flux that can reach the black hole. These simulations may be a reasonable model for low luminosity black hole accretion flows such as Sgr A* or M87.

Accepted by MNRAS. For animations see [https://smressle.bitbucket.io/animations.html]

References in corpus (24)

• First M87 Event Horizon Telescope Results. I. The Shadow of the Supermassive Black Hole
• First M87 Event Horizon Telescope Results. V. Physical Origin of the Asymmetric Ring
• The Athena++ Adaptive Mesh Refinement Framework: Design and Magnetohydrodynamic Solvers
• Global General Relativistic MHD Simulation of a Tilted Black-Hole Accretion Disk
• Galactic Centre stellar winds and Sgr A* accretion
• Observational appearance of inefficient accretion flows and jets in 3D GRMHD simulations: Application to Sgr~A*
• The Power of Imaging: Constraining the Plasma Properties of GRMHD Simulations using EHT Observations of Sgr A*
• Plasma diagnostic potential of 2p4f in N${}^{+}$ -- accurate wavelengths and oscillator strengths
• Variable accretion and emission from the stellar winds in the Galactic centre
• Ab Initio Horizon-Scale Simulations of Magnetically Arrested Accretion in Sagittarius A* Fed by Stellar Winds
• Sgr A* near-infrared flares from reconnection events in a magnetically arrested disc
• Black-hole jets without large-scale net magnetic flux
• The Surprisingly Small Impact of Magnetic Fields On The Inner Accretion Flow of Sagittarius A* Fueled By Stellar Winds
• The Radiative Efficiency and Spectra of Slowly Accreting Black Holes from Two-Temperature GRRMHD Simulations
• Dynamically important magnetic fields near the event horizon of Sgr A*
• Accretion of cool stellar winds on Sgr A*: another puzzle of the Galactic Centre?
• How important is non-ideal physics in simulations of sub-Eddington accretion onto spinning black holes?
• A Resolution Study of Magnetically Arrested Disks
• Tilted Disks around Black Holes: A Numerical Parameter Survey for Spin and Inclination Angle
• Stellar winds pump the heart of the Milky Way
• Decomposing the Internal Faraday Rotation of Black Hole Accretion Flows
• Evidence for a jet and outflow from Sgr A*: a continuum and spectral line study
• grim: A Flexible, Conservative Scheme for Relativistic Fluid Theories
• ALMA Detection of Extreme Blue-Shifted Ionized Gas Within 0.2 pc of Sgr A* from -480 to -300 km/s