Faraway quasars
نویسندگان
چکیده
منابع مشابه
Do Quasars Lens Quasars?
If the unexpectedly high frequency of quasar pairs with very different component redshifts is due to the lensing of a population of background quasars by the foreground quasar, typical lens masses must be ∼ 10M⊙ and the sum of all such quasar lenses would have to contain ∼ 0.005 times the closure density of the Universe. It then seems plausible that a very high fraction of all ∼ 10M⊙ gravitatio...
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Big Bang Nucleosynthesis (BBN) is the synthesis of the light nuclei, Deuterium (D or 2H), 3He, 4He and 7Li during the first few minutes of the universe. In this review we concentrate on recent data which give the primordial deuterium (D) abundance. We have measured the primordial D/H in gas with very nearly primordial abundances. We use the Lyman series absorption lines seen in the spectra of q...
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ژورنال
عنوان ژورنال: Nature
سال: 1986
ISSN: 0028-0836,1476-4687
DOI: 10.1038/324010c0