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Aims. An implicit algorithm for solving the equations of general relativistic hydrodynamics in conservative form in three-dimensional axi-symmetry is presented. This algorithm is a direct extension of the pseudo-Newtonian implicit radiative magnetohydrodynamical solver -IRMHDinto the general relativistic regime. Methods. We adopt the Boyer-Lindquist coordinates and formulate the hydrodynamical ...

We present a modified description of advection-dominated accretion flows with a geometrical viscosity. A simplified treatment of the dynamics of the flow in the inner relativistic part is suggested and results are compared with the galactic center source Sgr A.

A robust second order, shock-capturing numerical scheme for multi-dimensional special relativistic magnetohydrodynamics on computational domains with adaptive mesh refinement is presented. The base solver is a total variation diminishing Lax-Friedrichs scheme in a finite volume setting and is combined with a diffusive approach for controlling magnetic monopole errors. The consistency between th...

It is proven that, under mild physical assumptions, an isolated stationary relativistic perfect fluid consists of a finite number of cells fibred by invariant annuli or invariant tori. For axially symmetric circular flows it is shown that the fluid consists of cells fibred by rigidly rotating annuli or tori.

The PSR1259−63/SS2883 binary system consists of a Be star and a radio pulsar in a highly eccentric orbit. We discuss on very-high energy and high energy emissions from the particles accelerated in the Be star flows, due to the interactions of the relativistic pulsar wind and mass outflows of the star. The outflow parameters are constrained by the TeV observation results.

Turbulent Comptonization, a potentially important damping and radiation mechanism in relativistic accretion flows, is discussed. Particular emphasis is placed on the physical basis, relative importance, and thermodynamics of turbulent Comptonization. The effects of metal-absorption opacity on the spectral component resulting from turbulent Comptonization is considered as well. 1. Overview of Th...

We have undertaken the simulation of hydrodynamic flows with bulk Lorentz factors in the range 10 2 –10 6. We discuss the application of an existing relativistic, hydrodynamic primitive-variable recovery algorithm to a study of pulsar winds, and, in particular, the refinement necessary to admit such ultra-relativistic flows. We show that the use of an analytical quartic root finder is required ...

Non-Riemannian geometry of acoustic non-relativistic turbulent flows is irrotationally perturbed generating a acoustic geometry model with acoustic metric and acoustic Cartan contortion. The contortion term is due to nonlinearities in the turbulent fluid. The acoustic curvature and acoustic contortion are given by Dirac delta distributions. Violation of Lorentz invariance due to turbulence is c...