## Abstract

The two-dimensional structure of a thin accretion disk in the vicinity of a Schwarzschild black hole after passing a marginally stable orbit (r < 3r_{g}) is discussed in terms of the Grad-Shafranov hydrodynamic equation. The accretion disk is shown to be sharply compressed as the sonic surface is approached, so the mass flow here is no longer radial. As a result, the dynamic forces p[(v∇)v]θ, which are equal in magnitude to the pressure gradient ∇θP on the sonic surface, become significant in vertical balance. Therefore, the disk thickness in the supersonic region (and, in particular, near the black-hole horizon) may be assumed to be determined not by the pressure gradient but by the shape of ballistic trajectories.

Original language | English (US) |
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Pages (from-to) | 543-552 |

Number of pages | 10 |

Journal | Astronomy Letters |

Volume | 28 |

Issue number | 8 |

DOIs | |

State | Published - Aug 2002 |

## Keywords

- Black holes
- Neutron stars
- Pulsars

## ASJC Scopus subject areas

- Astronomy and Astrophysics
- Space and Planetary Science