Photoionization of Fe XV

Relativistic and resonance effects in the photoionization of Mg-like Fe~XV are investigated using the Breit-Pauli R-matrix Method (BPRM) at near-threshold and intermediate energies, complemented by the Relativistic Random Phase Approximation (RRPA) and multi-channel quantum defect theory in the energy region up to the L-shell ionization thresholds. The cross sections exhibit extensive resonance structures that considerably enhance the effective photoionization of Fe~XV. These results should be of general interest in photoionization modeling of X-ray sources observed by space observatories.