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

PASJ: Publications of the Astronomical Society of Japan

Asahina, Yuta¹  Mineshige, Shin¹  Kawashima, Tomohisa²  Takeuchi, Shun²  Ohsuga, Ken²  Kobayashi, Hiroshi³  Takahashi, Hiroyuki R³ 

[1] Center for Computational Astrophysics, National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka-shi, Tokyo 181-8588, Japan;Division of Theoretical Astronomy, National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka-shi, Tokyo 181-8588, Japan;School of Physical Sciences, Graduate University of Advanced Study (SOKENDAI), Shonan Village, Hayama, Kanagawa 240-0193, Japan

关键词: accretion, accretion disks;    black hole physics;    hydrodynamics;    instabilities;    radiation: dynamics;   

DOI  :  10.1093/pasj/psx157

学科分类：天文学(综合)

来源: Oxford University Press

【 摘 要 】

We perform global three-dimensional (3D) radiation-hydrodynamic (RHD) simulations of outflow from supercritical accretion flow around a 10 M⊙ 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 ∼102LE/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 M⊙, in rough agreement with the observations of some ultra-luminous X-ray sources.

【 授权许可】

CC BY