Mass-ratio and Magnetic Flux-Dependence of Modulated Accretion from Circumbinary Disks

Abstract

Accreting supermassive binary black holes (SMBBHs) are potential multi-messenger sources because they emit both gravitational wave and electromagnetic (EM) radiation. Past work has shown that their EM output may be periodically modulated by an asymmetric density distribution in the circumbinary disk, often called an "overdensity" or "lump;" this modulation could possibly be used to identify a source as a binary. We explore the sensitivity of the overdensity to SMBBH mass ratio and magnetic flux through the accretion disk. We find that the relative amplitude of the overdensity and its associated EM periodic signal both degrade with diminishing mass ratio, vanishing altogether somewhere between 1:2 and 1:5. Greater magnetization also weakens the lump and any modulation of the light output. We develop a model to describe how lump formation results from internal stress degrading faster in the lump region than it can be rejuvenated through accretion inflow, and predicts a threshold value in specific internal stress below which lump formation should occur and which all our lump-forming simulations satisfy. Thus, detection of such a modulation would provide a constraint on both mass-ratio and magnetic flux piercing the accretion flow.

32 pages, 30 color figures. Submitted to the Astrophysical Journal. Movies may be found at https://youtube.com/playlist?list=PLNaEA0qwDBaeApzLr2oarVKiO3AFnklTV

References in corpus (35)

• A possible close supermassive black-hole binary in a quasar with optical periodicity
• The Influence of Magnetic Field Geometry on the Evolution of Black Hole Accretion Flows: Similar Disks, Drastically Different Jets
• Viscous Hydrodynamics Simulations of Circumbinary Accretion Discs: Variability, Quasi-Steady State, and Angular Momentum Transfer
• Hydrodynamic Torques in Circumbinary Accretion Disks
• Binary Black-Hole Mergers in Magnetized Disks: Simulations in Full General Relativity
• Circumbinary Accretion from Finite and Infinite Disks
• Gas-driven inspiral of binaries in thin accretion disks
• On the origin of horseshoes in transitional discs
• Characteristic Signatures in the Thermal Emission from Accreting Binary Black Holes
• Three Dimensional MHD Simulation of Circumbinary Accretion Disks -2. Net Accretion Rate
• Equilibrium eccentricity of accreting binaries
• Evolution of gas disc-embedded intermediate mass ratio inspirals in the LISA band
• Accretion disks around binary black holes of unequal mass: GRMHD simulations of postdecoupling and merger
• Binary black hole mergers in gaseous disks: Simulations in general relativity
• A Periodically Varying Luminous Quasar at z=2 from the Pan-STARRS1 Medium Deep Survey: A Candidate Supermassive Black Hole Binary in the Gravitational Wave-Driven Regime
• Quasi-Periodic Behavior of Mini-Disks in Binary Black Holes Approaching Merger
• The evolution of large cavities and disc eccentricity in circumbinary discs
• The Keck Baryonic Structure Survey: Using foreground/background galaxy pairs to trace the structure and kinematics of circumgalactic neutral hydrogen at $z\sim 2$
• Quasi-Periodicity of Supermassive Binary Black Hole Accretion Approaching Merger
• Observing the inspiral of coalescing massive black hole binaries with LISA in the era of Multi-Messenger Astrophysics
• Gap, shadows, spirals, streamers: SPHERE observations of binary-disk interactions in GG Tau A
• Preventing Anomalous Torques in Circumbinary Accretion Simulations
• Minidisk dynamics in accreting, spinning black hole binaries: Simulations in full general relativity
• Long-Lived Eccentric Modes in Circumbinary Disks
• GRMHD prediction of coronal variability in accreting black holes
• Circumbinary Disk Accretion into Spinning Black Hole Binaries
• Discovery of a Candidate Binary Supermassive Black Hole in a Periodic Quasar from Circumbinary Accretion Variability
• Toward the unambiguous identification of supermassive binary black holes through Bayesian inference
• Accuracy of the post-Newtonian approximation. II. Optimal asymptotic expansion of the energy flux for quasicircular, extreme mass-ratio inspirals into a Kerr black hole
• Resolving the relative influence of strong field spacetime dynamics and MHD on circumbinary disk physics
• How bright are the gaps in circumbinary disk systems?
• Looking for the underlying cause of black hole X-ray variability in GRMHD simulations
• Time Domain Filtering of Resolved Images of Sgr A*
• Note on Accuracy of the Post-Newtonian Approximation for Extreme-Mass Ratio Inspirals: Retrograde Orbits
• The effect of cooling on the accretion of circumprimary discs inmerging supermassive black hole binaries

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• Multi-messenger Time-domain Signatures Of Supermassive Black Hole Binaries
• Gravitational Self-Lensing in Populations of Massive Black Hole Binaries
• Superposed metric for spinning black hole binaries approaching merger
• On the Role of Gas Cooling in the Dynamics of Circumbinary Disks
• Minidisk Influence on Flow Variability in Accreting Spinning Black Hole Binaries: Simulations in Full General Relativity
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