Michel accretion of a polytropic fluid with adiabatic index : global flows versus homoclinic orbits
Nov 24, 201517 pages
Published in:
- Class.Quant.Grav. 33 (2016) 10, 105016
- Published: Apr 27, 2016
e-Print:
- 1511.07728 [gr-qc]
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Abstract: (IOP)
We analyze the properties of a polytropic fluid that is radially accreted into a Schwarzschild black hole. The case where the adiabatic index γ lies in the range of has been treated in previous work. In this article, we analyze the complementary range of . To this purpose, the problem is cast into an appropriate Hamiltonian dynamical system, whose phase flow is analyzed. While, for , the solutions are always characterized by the presence of a unique critical saddle point, we show that, when , an additional critical point might appear, which is a center point. For the parametrization used in this paper, we prove that, whenever this additional critical point appears, there is a homoclinic orbit. Solutions corresponding to homoclinic orbits differ from standard transonic solutions with vanishing asymptotic velocities in two aspects: they are local (i.e., they cannot be continued to arbitrarily large radii), the dependence of the density or the value of the velocity on the radius is not monotonic.Note:
- 13 pages, 3 figures
- 04.20.-q
- 04.70.-s
- 98.62.Mw
- accretion flows
- black holes
- Hamiltonian dynamical systems
References(23)
Figures(3)
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- [2]
- [3]
- [4]
- [5]
- [6]
- [7]
- [8]
- [9]
- [10]
- [11]
- [12]
- [13]
- [14]
- [15]
- [16]
- [17]
- [18]
- [19]
- [20]
- [21]
- [22]
- [23]