Abstract
We perform global three-dimensional (3D) radiation-hydrodynamic (RHD) simulations of out- flow from supercritical accretion flow around a 10 Msun black hole. We only solve the outflow part, starting from the axisymmetric 2D simulation data in a nearly steady state but with small perturbations in a sinusoidal form being added in the azimuthal direction. The mass accretion rate onto the black hole is ~102 LE/c2 in the underlying 2D simulation data and the outflow rate is ~10 LE/c2 (with LE and c being the Eddington luminosity and speed of light, respectively). We first confirm the emergence of clumpy outflow, which was discovered by the 2D RHD simulations, above the photosphere located at a few hundreds of Schwarzschild radii (rS) from the central black hole. As prominent 3D features we find that the clumps have the shape of a torn sheet, rather than a cut string, and that they are rotating around the central black hole with a sub-Keplerian velocity at a distance of ~103 rS from the center. The typical clump size is ~30 rS or less in the radial direction, and is more elongated in the angular directions, ~hundreds of rS at most. The sheet separation ranges from 50 to 150 rS. We expect stochastic time variations when clumps pass across the line of the sight of a distant observer. Variation timescales are estimated to be several seconds for a black hole with mass of ten to several tens of Msun, in rough agreement with the observations of some ultra-luminous X-ray sources.
Original language | English |
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Article number | 22 |
Pages (from-to) | 1-12 |
Number of pages | 12 |
Journal | Publications of the Astronomical Society of Japan |
Volume | 70 |
Issue number | 2 |
Early online date | 8 Feb 2018 |
DOIs | |
Publication status | Published - Mar 2018 |
Externally published | Yes |
Keywords
- accretion
- accretion disks
- black hole physics
- hydrodynamics
- instabilities
- radiation: dynamics