OI, GeII, KrI & H abundances from HST UV spectra

Our objective is to undertake an investigation that goes beyond earlier abundance studies to see how these elements are influenced independently by three different environmental properties: (1) values of a generalized atomic depletion factor F_*_ due to condensations onto dust grains (revealed here by the abundances of Mg and Mn relative to H), (2) the fraction of H atoms in the form of H_2_/f(H_2_), and (3) the ambient intensity I of ultraviolet starlight relative to an average value in our part of the Galaxy I_0_.

As expected, the gas-phase abundances of all three elements exhibit negative partial correlations with F*. The abundances of free O atoms show significant positive partial correlations with logf(H_2_) and log(I/I_0_), while Ge and Kr exhibit negative partial correlations with log(I/I_0_) at marginal levels of significance. After correcting for these trends, the abundances of O relative to H show no significant variations with location, except for the already-known radial gradient of light-element abundances in the Milky Way.