First results from the Goddard High-Resolution Spectrograph - Elemental abundances in the diffuse clouds toward XI Persei

Abstract

An analysis is presented of high-resolution observations of ultraviolet interstellar absorption lines of dominant ion stages arising in the diffuse clouds toward Xi Per obtained with the Goddard High-Resolution Spectrograph. A detection of the weak intersystem line of semiforbidden C II 2325 A is reported. For C, O, and Mg, column densities are derived from both weak lines and the damping wings of strongly saturated lines. For Mg, the derived column densities differ by a factor three. Comparison of apparent column densities profiles, between lightly depleted and heavily depleted species indicates a transition from substantial depletions at v(solar) roughly 7.5 km/s to a decrease in depletion of a factor two or more for v(solar) = 7.5-20 km/s.