QSO 0130−4021: A Third QSO Showing a Low Deuterium‐to‐Hydrogen Abundance Ratio
نویسندگان
چکیده
منابع مشابه
The Deuterium Abundance in QSO Absorption Systems : A Mesoturbulent Approach
A new method, based on simulated annealing technique and aimed at the inverse problem in the analysis of intergalactic or interstellar complex spectra of hydrogen and metal lines, is outlined. We consider the process of line formation in clumpy stochastic media accounting for fluctuating velocity and density fields self-consistently. Two examples of the analysis of ‘H+D’-like absorptions seen a...
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We present a measurement of the deuterium to hydrogen ratio (D/H) in a metal-poor absorption system at redshift z = 2.504 towards the QSO 1009+2956. We apply the new method of Burles & Tytler (1997) to robustly determine D/H in high resolution Lyα forest spectra, and include a constraint on the neutral hydrogen column density determined from the Lyman continuum optical depth in low resolution s...
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The QSO lifetime tQ is one of the most fundamental quantities for understanding black hole and QSO evolution, yet it remains uncertain by several orders of magnitude. If tQ is long, then only a small fraction of galaxies went through a luminous QSO phase. In contrast, a short lifetime would require most galaxies today to have undergone a QSO phase in their youth. The current best estimates or c...
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ژورنال
عنوان ژورنال: The Astrophysical Journal
سال: 2000
ISSN: 0004-637X,1538-4357
DOI: 10.1086/308317