AAS 197, January 2001
Session 36. Deuterium Abundance in ISM: First {\it FUSE} Results
Display, Tuesday, January 9, 2001, 9:30am-7:00pm, Exhibit Hall

## [36.06] D/O and D/N towards HZ\,43: First FUSE Results

J.W. Kruk, J.C. Howk, M. Andre, H.W. Moos, W.R. Oegerle, C. Oliveira, K.R. Sembach (JHU), P. Chayer (UVIC/JHU), J.L. Linsky, B.E. Wood (U. Colorado), R. Ferlet, G. Hebrard, M. Lemoine, A. Vidal-Madjar (CNRS/IAP), G. Sonneborn (NASA/GSFC), FUSE Science Team

High resolution spectra of the DA white dwarf HZ\,43 covering the wavelength range 905--1187Å\ were obtained with the Far Ultraviolet Spectroscopic Explorer (FUSE) for the purpose of studying the deuterium abundance of the local interstellar medium. These spectra exhibit clean interstellar lines of O\,{\sc i} and N\,{\sc i}, permitting a determination of the column densities for these species. Only an upper limit to the D\,{\sc i} absorption could be determined, because of contamination by the H\,{\sc i} geocoronal airglow admitted by the large aperture used for this observation. Archival HST/GHRS spectra in the vicinity of Lyman \alpha were used instead to determine the D\,{\sc i} and H\,{\sc i} column densities, the latter determined from a fit to the damping wings of the Lyman~\alpha transition. Further FUSE observations of HZ\,43 using the smaller MDRS aperture will be obtained in order to better constrain the D\,{\sc i} column density using the Lyman-series lines in the FUSE bandpass.

We will present determinations of the column densities and uncertainties of interstellar D\,{\sc i}, H\,{\sc i}, O\,{\sc i}, and N\,{\sc i} along this sight line and discuss the potential sources of systematic error in these measurements.

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 to U. S. participants has been provided by NASA contract NAS5-32985.