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Radius of the accretion disc?

  1. Jun 7, 2009 #1


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    What is the inner radius of an accretion disc?

    Is it simply the radius of the smallest possible orbit of a massive particle (the marginally stable radius), 6M ?
  2. jcsd
  3. Jun 8, 2009 #2
    Hi tiny-tim

    In most cases, the inner edge of the accretion disk is considered to coincide with the marginally stable which is 6M for a static black hole, reducing to 1M for a maximal Kerr black hole where a/M=1, though there seems to be some debate that the properties of the accretion disk itself can have an effect on this-

    A couple of links-

    'Where is a Marginally Stable Orbit in Luminous Accretion Disk' by Ken-ya Watarai Watarai, Shin Mineshige
    http://quasar.cc.osaka-kyoiku.ac.jp/~watarai/presen/KoreaPoster2004.pdf [Broken]

    'The radiation properties of an accretion disk with a non-zero torque on its inner edge' by Xinwu Cao, Y.D. Xu

    'Black Hole Accretion Disks On The Edge' by Kristen Menou
    Last edited by a moderator: May 4, 2017
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