  We shall study in this paper the Lipschitz type stabilities and convergence
rates of Tikhonov regularization for the recovery of the radiativities in
elliptic and parabolic systems with Dirichlet boundary conditions. The
Lipschitz type stability estimates are derived. Due to the difficulty of the
verification of the existing source conditions or nonlinearity conditions for
the considered inverse radiativity problems in high dimensional spaces, some
new variational source conditions are proposed. The conditions are rigorously
verified in general dimensional spaces under the Lipschitz type stability
estimates and the reasonable convergence rates are achieved.
