Atomic data from the Iron Project. XVI. Photoionization cross sections and oscillator strengths for Fe V

Abstract

Large scale ab initio calculations of photoionization and dipole transition probabilities for Fe V are reported. The computations were carried out in the close coupling approximation using the R-matrix method including 34 LS terms of the target ion Fe VI. All bound states of Fe V with and are considered. The results include 1816 LS bound states, dipole oscillator strengths for 129.904 LS multiplets, and detailed photoionization cross sections with extensive resonance structures for all of the bound states. These data differ significantly in many cases from the earlier data calculated under the Opacity Project and other theoretical calculations. It is expected that the new data should yield more accurate Iron opacities, particularly in objects where Fe V is observed to be one of the dominant species, such as the atmospheres of hot, young white dwarfs at temperatures of 40.000 - 60.000 K. The present calculations were mainly carried out on the massively parallel Cray T3D with a parallelized version of the Iron Project R-matrix codes.