IUCAA Preprints

Permanent URI for this communityhttp://localhost:4000/handle/11007/149

Browse

Subject: search.filters.subject.Accretion, accretion disks

Search Results

Now showing 1 - 3 of 3
  • No Thumbnail Available
    Item
    Generalized Shock Solutions for Hydrodynamics Black Hole Accretion
    (2001-05-01) Das, Tapas K.
    For the first time, all available pseudo-Schwarzschild potentials are exhaustively used to investigate the possibility of shock formation in hydrodynamic, invicid, black hole accretion discs. It is shown that a significant region of parameter space spanned by important accretion parameters allows shock formation for flow in all potentials used in this work. This leads to the conclusion that the standing shocks are essential ingredients in accretion discs around non-rotating black holes in general. Using a complete general relativistic framework, equations governing multi-transonic black hole accretion and wind are also formulated and solved in the Schwarzschild metric. Shock solutions for accretion flow in various pseudo potentials are then compared with such general relativistic solutions to identify which potential is the best approximation of Schwarzschild space-time as far as the question of shock formation in black hole accretion discs is concerned.
  • No Thumbnail Available
    Item
    Description of pseduo-Newtonina potential for the relativistic accretion disk around kerr black holes
    (2002-04-01) Mukhopadhyay, B.
    We present a pseudo-Newtonian potential for accretion disk modeling around the rotating black holes. This potential can describe the general relativistic effects on accretion disk. As the inclusion of rotation in a proper way is very important at an inner edge of disk the potential is derived from the Kerr metric. This potential can reproduce all the essential properties of general relativity within 10% error even for rapidly rotating black holes.
  • No Thumbnail Available
    Item
    Origin and interpretation of kilohertz QPOs from strange stars in X-ray Binary system: Theoretical hydrodynamical description
    (2011-07-05) Mukhopadhyay, B.; Ray, Subharthi; Dey, Jishnu; et al.
    We model and interpret the Kilohertz QPOs from the hydrodynamical description of accretion disk around a rapidly rotating compact strange star. The higher QPO frequency is described by the viscous effects of accretion disk leading to shocks, while the lower one is taken to be the Keplerian motion of the accreting matter. Comparing our results with the observations for two of the fastest rotating compact stellar candidates namely, 4U 1636−53 and KS 1731−260, we find that they match to a very good approximation, thus interpreting them as strange stars.