Three-dimensional structure of clumpy outflow from supercritical accretion flow onto black holes

Hiroshi Kobayashi, Ken Ohsuga, Hiroyuki R. Takahashi, Tomohisa Kawashima, Yuta Asahina, Shun Takeuchi, Shin Mineshige

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11 Citations (Scopus)

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 languageEnglish
Article number22
Pages (from-to)1-12
Number of pages12
JournalPublications of the Astronomical Society of Japan
Volume70
Issue number2
Early online date8 Feb 2018
DOIs
Publication statusPublished - Mar 2018
Externally publishedYes

Keywords

  • accretion
  • accretion disks
  • black hole physics
  • hydrodynamics
  • instabilities
  • radiation: dynamics

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