Singular Limit to Strong Contact Discontinuity for a 1D Compressible Radiation Hydrodynamics Model

In this paper, we consider a singular limit of 1D compressible radiation hydrodynamics (CRHD) systems. This singular limit process corresponds to the physical problem of letting the Bouguer number become infinite and keeping the Boltzmann number constant. We show that the solution to the CRHD system converges to the contact discontinuity wave of the corresponding Euler system in the $L^2$-norm over $\mathbb{R}$ and in the $L^\infty$-norm away from the discontinuity line in any finite time T as the Bouguer number tends to infinity. At the same time, we give the convergence rates in terms of the reciprocal of the Bouguer number. Here we have no need to restrict the strength of the corresponding contact discontinuity to be small.