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Deuterium Abundance in the Local ISM and Possible Spatial Variations

Linsky, Jeffrey L.

Excellent HST/GHRS spectra of interstellar hydrogen and deuterium Lyman-alpha absorption toward nearby stars allow us to identify systematic errors that have plagued earlier work and to measure accurate values of the D/H ratio in local interstellar gas. Analysis of 12 sightlines through the Local Interstellar Cloud leads to a mean value of D/H = (…

Deuterium Observations in the Galaxy

Ferlet, R.; Vidal-Madjar, A.; Lemoine, M.

An accurate measurement of the primordial value of D/H would provide one of the best tests of nucleosynthesis models for the early Universe and the baryon density. Such evaluations have been traditionally made using present estimations of the deuterium abundance in the interstellar medium, extrapolated backwards in time with the use of galactic ev…

Galactic Evolution of the Light Elements: A New Set of B Observations

Primas, F.

The boron 2500 Angstroms spectral region has been observed with the Goddard High Resolution Spectrograph (GHRS) of the Hubble Space Telescope (HST) in a new set of metal-poor stars and analyzed by spectrum synthesis technique, adopting the most recent model atmospheres. By taking into account the Li and Be abundances available from the literature …