Relativistic and non-relativistic magnetohydrodynamic flows around compact stars

Thesis/Dissertation · Fri Jan 01 04:00:00 EST 1988

OSTI ID:5027506

Mobarry, C M

A set of theoretical tools are developed for studying the magnetized accretion disks and astrophysical jets in active galaxies. A general theory is developed for the steady axisymmetric flow of an ideal general-relativistic fluid around a Schwarzschild black hole. The theory leads to a second-order partial differential equation-a Grad-Shafranov equation-for the magnetic flux function. A variational principle is found which leads to the Grad-Shafranov equation, and facilitates the discussion of various limits of the Grad-Shafranov equation of interest in different astrophysical situations. The magnetic surface functions of the Grad-Shafranov method are shown to be the Lagrange multipliers of an energy principle. Thus, the magnetic surface functions are not arbitrary functions, but must be chosen consistent with physically stable equilibria. From the energy principle, a numerical artificial friction method is developed to solve the general relativistic Grad-Shafranov equation with fluid flow. This method is suited for the internal boundaries between elliptic and hyperbolic behavior present in magnetospheres with fluid flow. These surfaces pose difficulties for traditional numerical methods. The friction method is useful in exploring the range of functional forms for the magnetic surface functions that correspond to stable equilibria. The friction method is shown to be compatible with a theory for the slow dissipative evolution of a nearly ideal MHD fluid. A virial theorem is derived from the basic equations of general relativistic MHD. It is used to obtain an upper bound on the total energy in the electromagnetic field in terms of the total gravitational binding energy between the black hole and the matter (and energy) outside it.

• Research Organization: Cornell Univ., Ithaca, NY (USA)
• OSTI ID: 5027506
• Country of Publication: United States
• Language: English

Related Subjects

640102 -- Astrophysics & Cosmology-- Stars & Quasi-Stellar
Radio & X-Ray Sources
640105* -- Astrophysics & Cosmology-- Galaxies
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ACCRETION DISKS
ANALYTICAL SOLUTION
BLACK HOLES
COSMIC RADIO SOURCES
EXPANSION
FIELD THEORIES
FLUID FLOW
FLUID MECHANICS
GALAXIES
GALAXY NUCLEI
GENERAL RELATIVITY THEORY
HYDRODYNAMICS
MAGNETIC FLUX
MAGNETOHYDRODYNAMICS
MATHEMATICAL MODELS
MECHANICS
METRICS
PLASMA JETS
RELATIVITY THEORY
SCHWARZSCHILD METRIC