Accretion on massive black holes in galactic nuclei

  title={Accretion on massive black holes in galactic nuclei},
  author={V. G. Gurzadyan and Leonid M. Ozernoy},
STELLAR collisions and/or tidal break-up of stars by a massive black hole1–3 accompanied by subsequent accretion of the released gas onto the hole play a crucial part in most black hole models of quasars and active galactic nuclei. It is usually assumed that an accretion disk forms around the hole due to the large orbital momentum of a disrupting star. However, we show here that the accretion mostly has disk characteristics only when M < Mcr and becomes quasi-spherical when M ≫ Mcr. 
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