Explicit-Implicit Scheme for Relativistic Radiation Hydrodynamics

Understand

We propose an explicit-implicit scheme for numerically solving Special Relativistic Radiation Hydrodynamic (RRHD) equations, which ensures a conservation of total energy and momentum (matter and radiation).

• In our scheme, 0th and 1st moment equations of the radiation transfer equation are numerically solved without employing a flux-limited diffusion (FLD) approximation.
• For an hyperbolic term, of which the time scale is the light crossing time when the flow velocity is comparable to the speed of light, is explicitly solved using an approximate Riemann solver.
• Source terms describing an exchange of energy and momentum between the matter and the radiation via the gas-radiation interaction are implicitly integrated using an iteration method.