AAS 200th meeting, Albuquerque, NM, June 2002
Session 73. Interim Stellar Materials: Gas, Dust and Clouds
Display, Thursday, June 6, 2002, 9:20am-4:00pm, SW Exhibit Hall

[Previous] | [Session 73] | [Next]

[73.09] Interstellar Deuterium, Nitrogen and Oxygen Abundances Toward GD 246, Lan 23 and HZ 21: Results from the FUSE Mission

C. M. Oliveira (Johns Hopkins University), G. Hébrard (Inst. d\'{}Astrophysique de Paris), J. C. Howk (Johns Hopkins University), P. Chayer (Johns Hopkins University, University of Victoria), J. W. Kruk, H. W. Moos (Johns Hopkins University)

High-resolution spectra of the hot white dwarfs GD 246 (WD 2309+105), Lan 23 (WD 2247+583) and HZ 21 (WD 1211+332) were obtained with the Far Ultraviolet Spectroscopic Explorer (FUSE) in the wavelength range 905~-~1187~Å~to study the interstellar abundances of deuterium, nitrogen and oxygen. Existing Hubble Space Telescope STIS high resolution observations of GD 246 were used in conjunction with the FUSE data to determine the column densities of H I, C II*, S II and Si II. We determine the neutral hydrogen column density along this sight line by fitting the strong damping wings of interstellar Ly\alpha, using a newly computed model atmosphere to account for the stellar continuum in the vicinity of this line. The sight line to this star, located at a distance of 79 pc in the direction l~=~87.25\degr~and b~=~-45.11\degr, shows absorption by two different clouds. The velocity of one of the clouds is consistent with the expected velocity of the Local Interstellar Cloud along this direction.

Lan 23 probes gas in the galactic plane (l~=~107.64\degr,~b~=~-0.64\degr and d~=~126 pc). Molecular hydrogen up to J~=~3 is clearly seen along this line of sight.

HZ 21 lies at a distance of 115 pc in the direction l~=~175.04\degr~and b~=~80.03\degr. No molecular hydrogen is seen along this line of sight.

We present D~I/O~I and D~I/N~I measurements for Lan 23 and HZ 21 and D~I/O~I, D~I/N~I, D~I/H~I and O~I/H~I for GD 246. We compare our measurements with previously published studies of these ratios.

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 in part by NASA contract NAS5-32985 to Johns Hopkins University. Support for French participation in this study has been provided by CNES.

The author(s) of this abstract have provided an email address for comments about the abstract: oliveira@pha.jhu.edu

[Previous] | [Session 73] | [Next]

Bulletin of the American Astronomical Society, 34
© 2002. The American Astronomical Soceity.