Photoionization cross sections, branching ratios, and photoelectron angular-distribution asymmetry parameters have been calculated for all Ar (Z=18) subshells using the relativistic random-phase approximation, the relativistic random-phase approximation modified to include relaxation effects, and the relativistic random-phase approximation modified to include relaxation effects and Auger decay. Comparisons are made between the various theoretical results and experimental data. The importance of relaxation and Auger decay is seen to increase for deep inner subshells, particularly 1s and 2s. © 1996 The American Physical Society.