arXiv subjects

Bogusz Kinasiewicz

Publications and source records attributed to Bogusz Kinasiewicz.

5 recordsLinked to original sources

arXiv2006

General relativistic accretion with backreaction

The spherically symmetric steady accretion of polytropic perfect fluids onto a black hole is the simplest flow model that can demonstrate the effects of backreaction. Backreaction keeps intact most of the characteristics of the sonic point. For any such system the mass accretion rate achieves maximal value when the mass of the fluid is 1/3 of the total mass. Fixing the total mass of the system, one observes the existence of two weakly accreting regimes, one overabundant and the other poor in fluid content.

gr-qc↗

arXiv2006

From polytropic to barotropic perfect fluids in general-relativistic hydrodynamics

Two general-relativistic hydrodynamical models are considered: a model of self-gravitating static configurations of perfect fluid and a model of steady accretion of fluid onto a black hole. We generalise analytic results obtained for the original polytropic versions of these models onto a wider class of barotropic equations of state. The knowledge about the polytropic solutions is used to establish bounds on certain characteristic quantities appearing in both cases.

gr-qc↗

arXiv2006

Selfgravitation in a general-relativistic accretion of steady fluids

The selfgravity of an infalling gas can alter significantly the accretion of gases. In the case of spherically symmetric steady flows of polytropic perfect fluids the mass accretion rate achieves maximal value when the mass of the fluid is 1/3 of the total mass. There are two weakly accreting regimes, one over-abundant and the other poor in fluid content. The analysis within the newtonian gravity suggests that selfgravitating fluids can be unstable, in contrast to the accretion of test fluids.

gr-qc↗

arXiv2006

Universality and backreaction in a general-relativistic accretion of steady fluids

The spherically symmetric steady accretion of polytropic perfect fluids onto a black hole is the simplest flow model that can demonstrate the effects of backreaction. The analytic and numerical investigation reveals that backreaction keeps intact most of the characteristics of the sonic point. For any such system, with the only free parameter being the relative abundance of the fluid, the mass accretion rate achieves maximal value when the mass of the fluid is universally 1/3 of the total mass.

gr-qc↗

arXiv2004

Comparison of Two Stationary Spherical Accretion Models

The general relativistic accretion onto a black hole is investigated in which the motion is steady and spherically symmetrical, the gas being at rest at infinity. Two models with different equations of state are compared. Numerical calculations show that the predictions of the models are similar in most aspects. In the ultrarelativistic regime the allowed band of the asymptotic speed of sound and the mass accretion rate can be markedly different.

gr-qc↗