Stability of Accretion Disks around Rotating Black Holes: A Pseudo–General‐Relativistic Fluid Dynamical Study

Abstract

We discuss the solution of an accretion disk when the black hole is chosen to be rotating. We study how the fluid properties are affected for different rotation parameters of the black hole. We know that no cosmic object is static in the universe. Here the effect of the rotation of the black hole on spacetime is considered, following an earlier work of the author, where the pseudo-Newtonian potential was prescribed for the Kerr geometry. We show that, with the inclusion of rotation of the black hole, the valid disk parameter region dramatically changes, and the disk becomes unstable. Also we discuss the possibility of shocks in accretion disks around rotating black holes. When the black hole is chosen to be rotating, the sonic locations of the accretion disk get shifted or disappear, making the disk unstable. To bring it into the stable situation, the angular momentum of the accreting matter has to be reduced/enhanced (for co/counterrotating disk) by means of some physical process.