Where Is the Inner Edge of an Accretion Disk around a Black Hole

摘要: What is meant by the "inner edge" of an accretion disk around a black hole depends on property that defines edge. We discuss four such definitions, using data from recent high-resolution numerical simulations. These are (1) "turbulence edge," where flux-freezing becomes more important than turbulence in determining magnetic field structure; (2) "stress plunging matter loses dynamical contact with outer flow; (3) "reflection smallest radius capable producing significant X-ray reflection features; and (4) "radiation innermost place which luminosity emerges. All these edges dependent rate nonaxisymmetric time-variable. Although all generally located vicinity marginally stable orbit, displacements can occur, interpretations placing edge precisely at this point be misleading. If observations to used successfully as diagnostics strong gravity, models interpret them must take careful account distinctions.