Breathing Oscillations in a Global Simulation of a Thin Accretion Disk

Abstract

We study the oscillations of an axisymmetric, viscous, radiative, general relativistic hydrodynamical simulation of a geometrically thin disk around a non-rotating, $6.62M_{\odot }$ black hole. The numerical setup is initialized with a Novikov-Thorne, gas-pressure-dominated accretion disk, with an initial mass accretion rate of $\dot{m}=0.01L_{\mathrm{Edd}}/c^2$ (where $L_{\mathrm{Edd}}$ is the Eddington luminosity and $c$ is the speed of light). Viscosity is treated with the $\alpha$-prescription. The simulation was evolved for about $1000$ Keplerian orbital periods at three Schwarzschild radii (ISCO radius). Power density spectra of the radial and vertical fluid velocity components, the total (gas $+$ radiation) midplane pressure, and the vertical component of radiative flux from the photosphere, all reveal strong power at the local breathing oscillation frequency. The first, second and third harmonics of the breathing oscillation are also clearly seen in the data. We quantify the properties of these oscillations by extracting eigenfunctions of the radial and vertical velocity components and total pressure. This confirms that these oscillations are associated with breathing motion.

10 pages, 6figures, submitted to MNRAS

References in corpus (5)

• X-ray Properties of Black-Hole Binaries
• Semi-implicit scheme for treating radiation under M1 closure in general relativistic conservative fluid dynamics codes
• Numerical Simulations of Optically Thick Accretion onto a Black Hole - II. Rotating Flow
• Relativistic Viscous Radiation Hydrodynamic Simulations of Geometrically Thin Disks: I. Thermal and Other Instabilities
• The Dynamics of Truncated Black Hole Accretion Disks II: Magnetohydrodynamic Case

Cited by in corpus (5)

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• Disk Tearing Leads to Low and High Frequency Quasi Periodic Oscillations in a GRMHD Simulation of a Thin Accretion Disk
• Relativistic, Viscous, Radiation Hydrodynamic Simulations of Geometrically Thin Disks. II. Disk Variability
• Tilted Accretion Disks