Evolution of relativistic thin discs with a finite ISCO stress: I. Stalled accretion

Abstract

We present solutions to the relativistic thin disc evolutionary equation using an $\alpha$-model for the turbulent stress tensor. Solutions with a finite stress at the innermost stable circular orbit (ISCO) give rise to bolometric light curves with a shallow power law time dependence, in good agreement with those observed in tidal disruption events. A self-similar model based on electron scattering opacity, for example, yields a power law index of $-11/14$, as opposed to $-19/16$ for the case of zero ISCO stress. These solutions correspond to an extended period of relaxation of the evolving disc which, like the light curves they produce, is not sustainable indefinitely. Cumulative departures from the approximation of exact circular orbits cause the power law index to evolve slowly with time, leading eventually to the steeper fall-off associated with traditional zero ISCO stress models. These modified solutions are discussed in detail in a companion paper.

arXiv comment11 pages, 4 figures. Accepted for publication in MNRAS

References in corpus (14)

• Modelling the behaviour of accretion flows in X-ray binaries
• On the Dynamical Foundations of Alpha Disks
• Simulations of Magnetized Disks Around Black Holes: Effects of Black Hole Spin, Disk Thickness, and Magnetic Field Geometry
• New physical insights about Tidal Disruption Events from a comprehensive observational inventory at X-ray wavelengths
• Efficiency of Magnetized Thin Accretion Disks in the Kerr Metric
• Dependence of inner accretion disk stress on parameters: the Schwarzschild case
• Magnetized Accretion Inside the Marginally Stable Orbit around a Black Hole
• Global simulations of axisymmetric radiative black hole accretion disks in general relativity with a sub-grid magnetic dynamo
• Three-Dimensional Simulations of Magnetized Thin Accretion Disks around Black Holes: Stress in the Plunging Region
• Late-time UV observations of tidal disruption flares reveal unobscured, compact accretion disks
• On the Thermal Stability of Radiation Dominated Accretion Disks
• Relativistic Viscous Radiation Hydrodynamic Simulations of Geometrically Thin Disks: I. Thermal and Other Instabilities
• The general relativistic thin disc evolution equation
• The evolution of Kerr discs and late-time tidal disruption event light curves

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• An upper observable black hole mass scale for tidal disruption events with thermal X-ray spectra
• Hard X-ray emission from a Compton scattering corona in large black hole mass tidal disruption events
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