X-Ray Photoabsorption in Magnesium Ions

K-shell photoabsorption cross sections are necessary for determining elemental abundances of the interstellar medium (ISM) from observed X-ray spectra. Over the past few years, our group has computed reliable K-shell photoabsorption calculations for oxygen [1-3], neon [4,5], and carbon [6] ions. We extend our calculations to magnesium ions using a state-of-the-art R-matrix method that incorporates the important Auger broadening and pseudoresonanace-elimination effects. Comparisons with available independent-particle (IP) results and other available data will also be presented. \newline \newline This work was supported in part by NASA's Astronomy Physics Research and Analysis (APRA) and Solar and Heliospheric Physics (SHP) Supporting Research and Technology (SR\&T) programs. \newline \newline [1] T. W. Gorczyca and B. M. McLaughlin. J Phys. B. {\bf 33}, L859 (2000). \newline [2] A. M. Juett, {\it et al}., Astrophys. J. {\bf 612}, 308 (2004). \newline [3] J. Garcia {\it et al}, Astrophys. J. Supp. S. {\bf 158}, 68 (2005). \newline [4] T. W. Gorczyca., Phys. Rev. A. {\bf 61}, 024702 (2000). \newline [5] A. M. Juett, {\it et al}, Astrophys. J. {\bf 648}, 1066 (2006). \newline [6] M. F. Hasoglu, {\it et al}, Astrophys. J., (in preparation)