Simulations of accretion flows crossing the last stable orbit

Abstract

We use three dimensional magnetohydrodynamic simulations, in a pseudo-Newtonian potential, to study geometrically thin accretion disc flows crossing the marginally stable circular orbit around black holes. We concentrate on vertically unstratified and isothermal disk models, but also consider a model that includes stratification. In all cases, we find that the sonic point lies just inside the last stable orbit, with a modest increase in the importance of magnetic field energy, relative to the thermal energy, observed interior to this radius. The time-averaged gradient of the specific angular momentum of the flow, (dl/dr), is close to zero within the marginally stable orbit, despite the presence of large fluctuations and continuing magnetic stress in the plunging region. The result that the specific angular momentum is constant within the last stable orbit is in general agreement with traditional disk models computed using a zero-torque boundary condition at the last stable orbit.

ApJ, in press. Revised to match accepted version. References corrected

References in corpus (7)

• The Formation and Structure of a Strongly Magnetized Corona above Weakly Magnetized Accretion Disks
• Global Magnetohydrodynamical Simulations of Accretion Tori
• Magnetic Stress at the Marginally Stable Orbit: Altered Disk Structure, Radiation, and Black Hole Spin Evolution
• Global MHD Simulation of the Inner Accretion Disk in a Pseudo-Newtonian Potential
• Efficiency of Magnetized Thin Accretion Disks in the Kerr Metric
• General Relativistic Simulations of Jet Formation in a Rapidly Rotating Black Hole Magnetosphere
• The properties of the relativistic iron K-line in NGC 3516

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