Integral form of the time-dependent radiation transfer equation—II. Inhomogeneous spherical media

Abstract

The integral form of the radiation transfer equation, with spherical symmetry for a non-isotropic, time-dependent, inhomogeneous, non-scattering medium is given for arbitrary initial and boundary conditions. The optical depth is generalized to an optical retardation and a separation parameter is introduced to separate boundary and initial conditions. The static solution is identical to the asymptotic form of the time-dependent solution.