منابع مشابه
Deuterium astration in the local disc and beyond
Estimates of the interstellar deuterium abundance span a wide range of values. Until recently, it was customary to adopt the abundance of deuterium measured in the Local Bubble as representative of the local one. Now, it is becoming unclear whether the true local deuterium abundance is significantly higher or lower than this value, depending on the interpretation given to current data. It is im...
متن کاملCosmological Implications of Two Conflicting Deuterium Abundances
Constraints on big bang nucleosynthesis (BBN) and on cosmological parameters from conflicting deuterium observations in different high red-shift QSO systems are discussed. The high deuterium observations by Carswell et al., Songaila et al., and Rugers & Hogan is consistent with He and Li observations and Standard BBN (Nν =3) and allows Nν ≤ 3.6 at 95% C.L., but is inconsistent with local observ...
متن کاملCosmological Implications of Two Con icting Deuterium Abundances
Constraints on big bang nucleosynthesis (BBN) and on cosmological parameters from con icting deuterium observations in di erent high red-shift QSO systems are discussed. The high deuterium observations by Carswell et al., Songaila et al., and Rugers & Hogan is consistent with He and Li observations and Standard BBN (N =3) and allows N 3:6 at 95% C.L., but is inconsistent with local observations...
متن کاملCosmological Deuterium Abundance and the Baryon Density of the Universe
Standard big bang nucleosynthesis (BBNS) promises accurate predictions of the primordial abundances of deuterium, helium-3, helium-4 and lithium-7 as a function of a single parameter. Previous measurements have nearly always been interpreted as confirmation of the model (1). Here we present a measurement of the deuterium to hydrogen ratio (D/H) in a newly discovered high redshift metal-poor gas...
متن کاملThe Cosmological Baryon Density from Deuterium in Qso Spectra
The primordial D/H ratio now provides the best measure of the cosmological density of baryons. We describe in detail how we deduce the D/H ratio from absorption lines in the spectra of quasars, and we present our first two measurements of D/H in different QSOs, which agree to within the random errors. We describe how we correct D/H for blending with Lyman alpha forest H lines. For our two QSOs ...
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ژورنال
عنوان ژورنال: The Astrophysical Journal
سال: 1985
ISSN: 0004-637X,1538-4357
DOI: 10.1086/163000