AAS 207th Meeting, 8-12 January 2006
Session 175 Recent Discoveries in the Far UV
Poster, Thursday, 9:20am-4:00pm, January 12, 2006, Exhibit Hall

## [175.04] Deuterium, Oxygen, and Nitrogen Abundance Toward LSE 44

S.D. Friedman (STScI), G. Hebrard (IAP), T.M. Tripp (UMASS), P. Chayer (JHU), K.R. Sembach (STScI)

We present FUSE measurements of D, O, N, H2, and \ion{Fe}{2}, and IUE measurements of H toward LSE 44, an sdO star at a distance of 554±6 pc. This is among the most distant Galactic targets for which D/H, D/O, and D/N have been measured. Both profile fitting and curve-of-growth techniques have been utilized in the analysis. We find D/H = (2.24+1.39-1.32) \times 10-5, D/O = (1.99+1.30-0.67) \times 10-2, D/N = (2.75+1.19-0.89) \times 10-1, and O/H = (1.13+0.96-0.71) \times 10-3 (all errors 2\sigma). This is one of the few sight lines probing material well beyond the Local Bubble for which D/H is higher than the Local Bubble value. Sight line to sight line variability of D/H for some targets, particularly those outside the Local Bubble, could be explained by varying degrees of depletion of deuterium onto dust grains, by infall of deuterium-rich primordial material, or by some other mechanism. However, D/O for these distant targets is uniform, and this discrepancy has yet to be explained.

This work is based on data obtained for the Guaranteed Time Team by the NASA-CNES-CSA FUSE mission operated by The Johns Hopkins University. Financial support has been provided to U.S. participants by NASA and to French participants by CNES.