Measurements of low temperature dielectronic recombination in L-shell iron for modeling X-ray photoionized cosmic plasmas

The iron L-shell ions (Fe17+ to Fe23+) play an important role in determin- ing the thermal and ionization structures and line emission from photoionized plasmas. Current uncertainties in the theoretical low temperature dielectronic recombination (DR) rate coefficients for these ions significantly affect our ability to model and inter- pret the line emission from observations of photoionized plasmas. To help resolve this issue, we have initiated a program of laboratory measurements to produce reliable low temperature DR rates for the L-shell iron. Here we present some of our recent results and discuss some of the astrophysical implications.