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Full-Text Articles in Cosmology, Relativity, and Gravity

Transonic Inviscid Disc Flows In The Schwarzschild Metric – I, Menas Kafatos, Ruixin Yang Jan 1994

Transonic Inviscid Disc Flows In The Schwarzschild Metric – I, Menas Kafatos, Ruixin Yang

Mathematics, Physics, and Computer Science Faculty Articles and Research

The coupled hydrodynamic equations governing equatorial flows applicable to inviscid disc accretion in the Schwarzschild metric are solved analytically and numerically. Here, we concentrate on the transonic solutions, that represent physically allowed accretion on to black holes. A polytropic equation linking gas pressure and density is assumed, and solutions are obtained for different conditions, such as isothermal and adiabatic gas flows. The dependence of those solutions on the angular momentum is explored. Under certain conditions, when there exist multiple possible sonic points, the numerical simulation automatically zeros in to the unique transonic solution passing through one of the sonic points.


Relativistic Particle Transport In Hot Accretion Disks, P. A. Becker, Menas Kafatos, M. Maisack Jan 1994

Relativistic Particle Transport In Hot Accretion Disks, P. A. Becker, Menas Kafatos, M. Maisack

Mathematics, Physics, and Computer Science Faculty Articles and Research

Accretion disks around rapidly rotating black holes provide one of the few plausible models for the production of intense radiation in AGNs above energies of several hundred MeV. The rapid rotation of the hole increases the binding energy per nucleon in the last stable orbit relative to the Schwarzschild case, and naturally leads to ion temperatures in the range 10^12-10^13 K for sub-Eddington accretion rates. The protons in the hot inner region of a steady, two-temperature disk form a reservoir of energy that is sufficient to power the observed EGRET outbursts if the black hole mass is 10^10 M0 • …