Deuterium and Oxygen toward Feige 110: Results from the FUSE Mission

We present measurements of the column densities of interstellar DI and OImade with the Far Ultraviolet Spectroscopic Explorer (FUSE), and of HI madewith the International Ultraviolet Explorer (IUE) toward the sdOB star Feige110 [(l,b) = (74.09, -59.07); d = 179 +265 -67 pc; z = -154 +57 -227 pc]. Ourdetermination of the DI column density made use of curve of growth fitting andprofile fitting analyses, while our OI column density determination used onlycurve of growth techniques. The HI column density was estimated by fitting thedamping wings of the interstellar Ly alpha profile. We find log N(DI) = 15.47+/- 0.06, log N(OI) = 16.73 +/- 0.10, and log N(HI) = 20.14 +0.13 -0.20 (allerrors 2 sigma). This implies D/H = (2.14 +/- 0.82) x 10^-5, D/O = (5.50 +1.64-1.33) x 10^-2, and O/H = (3.89 +/- 1.67) x 10^-4. Taken with the FUSE resultsreported in companion papers (Moos et al. 2001) and previous measurements ofthe local interstellar medium, this suggests the possibility of spatialvariability in D/H for sight lines exceeding ~100 pc. This result may constrainmodels which characterize the mixing time and length scales of material in thelocal interstellar medium.Comment: 24 pages, 9 figures. Accepted for publication in the Astrophysical Journal Supplement Series. Replacement corrects a typo in original submissio