GRMHD simulations of black hole accretion variabilities: Implications to hard state X-ray binary transients
arXiv:2504.17005 · doi:10.1093/mnras/stag148
Abstract
Using high-resolution general relativistic magnetohydrodynamic (GRMHD) simulations, we investigate accretion flows around spinning black holes and identify three distinct accretion states. Our results suggest the origin of the complex phenomenology observed across the black hole mass spectrum as the interplay between magnetic and gravitational fields. The magnetically arrested disk (MAD) state, characterized by strong magnetic fields (plasma-), exhibits powerful jets, highly variable accretion, and significant sub-Keplerian motion. On the other hand, weakly magnetized disks (plasma-), known as the standard and normal evolution (SANE) state, show steady accretion with primarily winds. An intermediate state bridges the gap between MAD and SANE regimes, with moderate magnetic support (plasma-) producing mixed outflow morphologies and complex variability. This unified framework has many implications including its possible connection to extreme variability of GRS 1915+105, particularly in its hard spectral states. It also suggests the possible origin of steady jets of Cyg X-1 and the unusually high luminosities (even super-Eddington based on stellar mass black hole) of HLX-1 without requiring super-Eddington mass accretion rates. Our simulations reveal a hierarchy of timescales that explain the rich variety of variability patterns, with magnetic processes driving transitions between states. Comparing two with three dimensional simulations demonstrates that while quantitative details differ, the qualitative features distinguishing different accretion states remain robust.
15 pages including 15 figures (21 pdf files) and 6 tables; version accepted for publication in MNRAS
References in corpus (24)
- Efficient Generation of Jets from Magnetically Arrested Accretion on a Rapidly Spinning Black Hole
- General Relativistic Magnetohydrodynamic Simulations of Magnetically Choked Accretion Flows around Black Holes
- HARM: A Numerical Scheme for General Relativistic Magnetohydrodynamics
- Magnetically Arrested Disk: An Energetically Efficient Accretion Flow
- General Relativistic Magnetohydrodynamic Simulations of Jet Formation and Large-Scale Propagation from Black Hole Accretion Systems
- Three-dimensional MHD Simulations of Radiatively Inefficient Accretion Flows
- GRMHD Simulations of Magnetized Advection Dominated Accretion on a Non-Spinning Black Hole: Role of Outflows
- The Event Horizon General Relativistic Magnetohydrodynamic Code Comparison Project
- Angular Momentum Transport by MHD Turbulence in Accretion Disks: Gas Pressure Dependence of the Saturation Level of the Magnetorotational Instability
- Black hole flares: ejection of accreted magnetic flux through 3D plasmoid-mediated reconnection
- Assessing Quantitative Results in Accretion Simulations: From Local to Global
- Large-Scale Poloidal Magnetic Field Dynamo Leads to Powerful Jets in GRMHD Simulations of Black Hole Accretion with Toroidal Field
- Variability in black hole accretion discs
- Magnetized Tori around Kerr Black Holes: Analytic Solutions with a Toroidal Magnetic Field
- H-AMR: A New GPU-accelerated GRMHD Code for Exascale Computing With 3D Adaptive Mesh Refinement and Local Adaptive Time-stepping
- The large scale magnetic fields of thin accretion disks
- Flux eruption events drive angular momentum transport in magnetically arrested accretion flows
- Universal at last? The splashback mass function of dark matter halos
- Optical variability of the accretion disk around the intermediate mass black hole ESO 243-49 HLX-1 during the 2012 outburst
- Strongly magnetized accretion with low angular momentum produces a weak jet
- Accretion Flow Morphology in Numerical Simulations of Black Holes from the ngEHT Model Library: The Impact of Radiation Physics
- Magnetized advective accretion flows: formation of magnetic barriers in Magnetically Arrested Discs
- Hydromagnetics of advective accretion flows around black holes: Removal of angular momentum by large scale magnetic stresses
- Role of magnetically dominated disc-outflow symbiosis on bright hard-state black hole sources: ultra-luminous X-ray sources to quasars