The impact of resistivity on the variability of black hole accretion flows

Abstract

Context. The accretion of magnetized plasma onto black holes is a complex and dynamic process, where the magnetic field plays a crucial role. The amount of magnetic flux accumulated near the event horizon significantly impacts the accretion flow behavior. Resistivity, a measure of how easily magnetic fields can dissipate, is thought to be a key factor influencing this process. This work explores the influence of resistivity on accretion flow variability. We investigate simulations reaching the magnetically arrested disk (MAD) limit and those with an initial multi-loop magnetic field configuration. Methods. We employ 3D resistive general relativistic magnetohydrodynamic (GRMHD) simulations to model the accretion process under various regimes, where resistivity has a global uniform value. Results. Our findings reveal distinct flow behaviors depending on resistivity. High resistivity simulations never achieve the MAD state, indicating a disturbed magnetic flux accumulation process. Conversely, low resistivity simulations converge towards the ideal MHD limit. The key results are: i) For the standard MAD model, resistivity plays a minimal role in flow variability, suggesting that flux eruption events dominate the dynamics. ii) High resistivity simulations exhibit strong magnetic field diffusion into the disk, rearranging efficient magnetic flux accumulation from the accretion flow. iii) In multi-loop simulations, resistivity significantly reduces flow variability, which was not expected. However, magnetic flux accumulation becomes more variable due to frequent reconnection events at very low resistivity values. Conclusions. This study shows that resistivity affects how much the flow is distorted due to magnetic field dissipation. Our findings provide new insights into the interplay between magnetic field accumulation, resistivity, variability and the dynamics of black hole accretion.

arXiv comment8 pages, Accepted in A&A

References in corpus (50)

• First M87 Event Horizon Telescope Results. I. The Shadow of the Supermassive Black Hole
• First Sagittarius A* Event Horizon Telescope Results. I. The Shadow of the Supermassive Black Hole in the Center of the Milky Way
• Efficient Generation of Jets from Magnetically Arrested Accretion on a Rapidly Spinning Black Hole
• Event-horizon-scale structure in the supermassive black hole candidate at the Galactic Centre
• Magnetically Arrested Disk: An Energetically Efficient Accretion Flow
• Near-infrared flares from accreting gas around the supermassive black hole at the Galactic Centre
• First M87 Event Horizon Telescope Results. VIII. Magnetic Field Structure near The Event Horizon
• Rapid X-ray flaring from the direction of the supermassive black hole at the Galactic Centre
• Fast Reconnection in High-Lundquist-Number Plasmas Due to Secondary Tearing Instabilities
• First Sagittarius A* Event Horizon Telescope Results. V. Testing Astrophysical Models of the Galactic Center Black Hole
• Three-dimensional MHD Simulations of Radiatively Inefficient Accretion Flows
• Fast magnetic reconnection in the plasmoid-dominated regime
• The Event Horizon General Relativistic Magnetohydrodynamic Code Comparison Project
• ECHO: an Eulerian Conservative High Order scheme for general relativistic magnetohydrodynamics and magnetodynamics
• The Current Ability to Test Theories of Gravity with Black Hole Shadows
• The Black Hole Accretion Code
• Magnetic Reconnection and Hot Spot Formation in Black Hole Accretion Disks
• Resistive Solutions for Pulsar Magnetospheres
• Magnetically Arrested Disks and Origin of Poynting Jets: Numerical Study
• The simultaneous spectrum of Sgr A* from 20cm to 1mm and the nature of the mm-excess
• Semi-global simulations of the magneto-rotational instability in core collapse supernovae
• Magnetorotational instability in relativistic hypermassive neutron stars
• A characteristic optical variability timescale in astrophysical accretion disks
• Innermost collimation structure of the M87 jet down to ~ten Schwarzschild radii
• Constrained transport and adaptive mesh refinement in the Black Hole Accretion Code
• Plasmoid formation in global GRMHD simulations and AGN flares
• Black-hole jets without large-scale net magnetic flux
• State-of-the-art energetic and morphological modelling of the launching site of the M87 jet
• Fast reconnection in relativistic plasmas: the magnetohydrodynamics tearing instability revisited
• General relativistic resistive magnetohydrodynamics with robust primitive variable recovery for accretion disk simulations
• Gamma-Ray Light Curves from Pulsar Magnetospheres with Finite Conductivity
• General relativistic MHD simulations of non-thermal flaring in Sagittarius A*
• Relativistic resistive magnetohydrodynamic reconnection and plasmoid formation in merging flux tubes
• On the opening angle of magnetised jets from neutron-star mergers: the case of GRB170817A
• Resistive relativistic MHD simulations of astrophysical jets
• On the measurements of numerical viscosity and resistivity in Eulerian MHD codes
• Striped Blandford/Znajek jets from advection of small scale magnetic field
• Black hole magnetosphere with small scale flux tubes--II. Stability and dynamics
• Black hole magnetosphere with small scale flux tubes
• Two-Temperature GRMHD Simulations of Black Hole Accretion Flows with Multiple Magnetic Loops
• Magnetorotational instability in magnetic diffusion dominated accretion discs
• Radiation Hydrodynamics in Kerr Spacetime: Equations without Coordinate Singularity at the Event Horizon
• Magnetically inspired explosive outflows from neutron-star mergers
• Effective resistivity in relativistic collisionless plasmoid-mediated reconnection
• The Variability of the Black-Hole Image in M87 at the Dynamical Time Scale
• Dynamics and Emission Properties of Flux Ropes from Two-Temperature GRMHD Simulations with Multiple Magnetic Loops
• Magnetic field structure in the vicinity of a super-massive black hole in low luminosity galaxies: the case of Sgr A*
• The 1.4 mm core of Centaurus A: First VLBI results with the South Pole Telescope
• The magnetic Rayleigh-Taylor instability around astrophysical black holes
• Numerical viscosity in simulations of the two-dimensional Kelvin-Helmholtz instability

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• Global resistive MHD accretion flows around spinning AGNs: impact of resistivity on MAD state
• Identifying Long Radio Transients with Accompanying X-Ray Emission as Disk-Jet Precessing Black Holes: The Case of ASKAP J1832-0911
• Full-polarization millimeter wavelength variability of Sagittarius A* during the 2018 EHT campaign
• The azimuthal structure of magnetically arrested disks during flux eruption events