One Percent Determination of the Primordial Deuterium Abundance
نویسندگان
چکیده
منابع مشابه
Primordial Deuterium Abundance and Cosmic Baryon Density
The comparison of cosmic abundances of the light elements with the density of baryonic stars and gas in the universe today provides a critical test of big bang theory and a powerful probe of the nature of dark matter. A new technique allows determination of cosmic deuterium abundances in quasar absorption clouds at large redshift, allowing a new test of big bang homogeneity in diverse, very dis...
متن کاملPrecision Measures of the Primordial Abundance of Deuterium
We report the discovery of deuterium absorption in the very metal-poor ([Fe/H]=−2.88) damped Lyman-α system at zabs = 3.06726 toward the QSO SDSS J1358+6522. On the basis of 13 resolved D i absorption lines and the damping wings of the H i Lyman α transition, we have obtained a new, precise measure of the primordial abundance of deuterium. Furthermore, to bolster the present statistics of preci...
متن کاملMeasuring the primordial deuterium abundance during the cosmic dark ages.
We discuss how measurements of fluctuations in the absorption of cosmic microwave background photons by neutral gas at redshifts z approximately 7-200 could reveal the primordial deuterium abundance of the Universe. The strength of the cross-correlation of brightness-temperature fluctuations in the redshifted 21-cm line of hydrogen with those in the redshifted 92-cm line of deuterium is proport...
متن کاملA Uniform Primordial Deuterium Abundance Stemmed from Qso Observations
The discordance between ‘low’ and ‘high’ primordial D/H measurements can be considerably reduced if the analysis of the H+D profiles accounts for the correlated velocity field of bulk motion. We have re-estimated the value of D/H at z = 3.572 towards Q1937–1009 (‘low’ D/H = (3.3±0.3)×10 [3]) and at z = 0.701 towards Q1718+4807 (‘high’ D/H = (2.0±0.5)×10 [15]) and found that a single D/H value f...
متن کاملThe Primordial Helium-4 Abundance Determination: Systematic Effects
By extrapolating to O/H = N/H = 0 the empirical correlations Y –O/H and Y –N/H defined by a relatively large sample of ∼ 45 Blue Compact Dwarfs (BCDs), we have obtained a primordial Helium mass fraction Yp= 0.2443±0.0015 with dY /dZ = 2.4±1.0. This result is in excellent agreement with the average Yp= 0.2452±0.0015 determined in the two most metal-deficient BCDs known, I Zw 18 (Z⊙/50) and SBS 0...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: The Astrophysical Journal
سال: 2018
ISSN: 1538-4357
DOI: 10.3847/1538-4357/aaab53