Pseudo-Schwarzschild Spherical Accretion as a Classical Black Hole Analogue

Abstract

We demonstrate that a spherical accretion onto astrophysical black holes, under the influence of Newtonian or various post-Newtonian pseudo-Schwarzschild gravitational potentials, may constitute a concrete example of classical analogue gravity naturally found in the Universe. We analytically calculate the corresponding analogue Hawking temperature as a function of the minimum number of physical parameters governing the accretion flow. We study both the polytropic and the isothermal accretion. We show that unlike in a general relativistic spherical accretion, analogue white hole solutions can never be obtained in such post-Newtonian systems. We also show that an isothermal spherical accretion is a remarkably simple example in which the only one information--the temperature of the fluid, is sufficient to completely describe an analogue gravity system. For both types of accretion, the analogue Hawking temperature may become higher than the usual Hawking temperature. However, the analogue Hawking temperature for accreting astrophysical black holes is considerably lower compared with the temperature of the accreting fluid.

Final Version to appear in the journal General Relativity & Gravitation, Volume 27, Issue 11, 2005. 17 pages, Two colour and one black and white figures. Typos corrected. Recent reference on analogue effect in relativistic accretion disc added

References in corpus (12)

• Acoustic black holes: horizons, ergospheres, and Hawking radiation
• Dumb Holes and the Effects of High Frequencies on Black Hole Evaporation
• Trans-Planckian redshifts and the substance of the space-time river
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Cited by in corpus (13)

• Analogue Gravity
• Black-Hole Accretion Disc as an Analogue Gravity Model
• Acoustic horizons in axially symmetric relativistic accretion
• On the stability of self-gravitating accreting flows
• Acoustic geometry through perturbation of mass accretion rate - radial flow in static spacetimes
• On Spin Dependence of Relativistic Acoustic Geometry
• On the stability of steady general-relativistic accretion and analogue black holes
• Linear perturbations of low angular momentum accretion flow in the Kerr metric and the corresponding emergent gravity phenomena
• Relativistic sonic geometry for isothermal accretion in the Kerr metric
• Effective sound speed in relativistic accretion discs around Schwarzschild black holes
• Carter-Penrose diagrams for emergent spacetime in axisymmetrically accreting black hole systems
• Dynamical analogue spacetimes in non-relativistic flows
• Emergent gravity through non-linear perturbation