author={David Kirkman and David Tytler and Nao Suzuki and John M. O’Meara and Dan Lubin},
  journal={Astrophysical Journal Supplement Series},
We report the detection of deuterium absorption at redshift 2.525659 toward Q1243+3047. We describe improved methods to estimate the deuterium to hydrogen abundance ratio (D/H) in absorption systems, including improved modeling of the continuum level, the Lyα forest, and the velocity structure of the absorption. Together with improved relative flux calibration, these methods give D/H = 2.42 × 10-5 from our Keck I HIRES spectra of Q1243+3047, where the error is from the uncertainty in the shape… Expand
The Deuterium-to-Hydrogen Abundance Ratio toward the QSO SDSS J155810.16–003120.0*
We present a measurement of the D/H abundance ratio in a metal-poor damped Lyα (DLA) system along the sight line of QSO SDSS 1558-0031. The DLA system is at redshift z = 2.70262 and has a neutralExpand
A robust deuterium abundance; re-measurement of the z = 3.256 absorption system towards the quasar PKS 1937−101
The primordial deuterium abundance is an important tracer of the fundamental physics taking place during big bang nucleosynthesis. It can be determined from absorption features along the line ofExpand
The Galactic deuterium abundance and dust depletion: insights from an expanded Ti/H sample
The primordial abundance of deuterium (D/H) yields a measure of the density of baryons in the Universe and is an important complement to determinations from cosmic microwave background (CMB)Expand
Deuterium Abundance in the Interstellar Gas of the Galactic Anticenter from the 327 MHz Line
The deuterium abundance in the primordial gas formed during the big bang is dependent on the baryon-to-photon ratio during nucleosynthesis. We report a measurement of the deuterium-to-hydrogen (D/H)Expand
HD molecules at high redshift: the absorption system at z = 2.3377 towards Q 1232 + 082★
We present a detailed analysis of the H 2 and HD absorption lines detected in the damped Lyman α (DLA) system at z abs = 2.3377 towards the quasar Q 1232 + 082. We show that this intervening cloudExpand
Cosmological Parameters σ8, the Baryon Density Ωb, the Vacuum Energy Density ΩΛ, the Hubble Constant and the UV Background Intensity from a Calibrated Measurement of H I Lyα Absorption at z = 1.9
We identify a concordant model for the intergalactic medium (IGM) at redshift z = 1.9 that uses popular values for cosmological and astrophysical parameters and accounts for all baryons with anExpand
Deuterium at high-redshift: Primordial abundance in the zabs = 2.621 damped Ly-alpha system towards CTQ247
We report the detection of neutral deuterium in the low-metallicity damped Lyman-α system at zabs = 2.621 towards the quasar CTQ 247. Using a high signal-to-noise and high spectral resolution (R = 60Expand
The Abundance of Deuterium in the Warm Neutral Medium of the Lower Galactic Halo
We use high-resolution ultraviolet spectra to obtain Milky Way interstellar column densities of H I, D I, O I, S II, Fe II, and P II toward the QSO HE 0226-4110 in the Galactic direction l = 253.4?Expand
A one percent determination of the primordial deuterium abundance
We report a reanalysis of a near-pristine absorption system, located at a redshift z_abs=2.52564 towards the quasar Q1243+307, based on the combination of archival and new data obtained with theExpand
What Is the Total Deuterium Abundance in the Local Galactic Disk
Analyses of spectra obtained with the Far Ultraviolet Spectroscopic Explorer (FUSE) satellite, together with spectra from the Copernicus and interstellar medium absorption profile spectrographExpand


The Deuterium abundance toward QSO 1009+2956
We present a measurement of the deuterium to hydrogen ratio (D/H) in a metal-poor absorption system at redshift z = 2.504 toward the QSO 1009+2956. We apply the new method of Burles & Tytler toExpand
Cosmological baryon density derived from the deuterium abundance at redshift z = 3.57
A baryon density that is 5% of the critical density required to close the Universe is calculated, consistent with that in the interstellar medium (after allowing for Galactic chemical evolution). Expand
A New Measurement of the Primordial Abundance of Deuterium: Toward Convergence with the Baryon Density from the Cosmic Microwave Background?
From the analysis of the near-UV spectrum of the quasar (QSO)2206-199, obtained with a long series of exposures with the Space Telescope Imaging Spectrograph on the Hubble Space Telescope, we deduceExpand
The Deuterium to Hydrogen Abundance Ratio toward a Fourth QSO: HS 0105+1619
We report the measurement of the primordial D/H abundance ratio toward QSO HS 0105+1619. The column density of the neutral hydrogen in the z 2.536 Lyman limit system is high, log N = 19.422 ± 0.009Expand
The Deuterium Abundance toward Q1937–1009
We present a new measurement of the deuterium-to-hydrogen ratio (D/H) in the Lyman limit absorption system at z = 3.572 toward Q1937-1009. Tytler, Fan & Burles (TFB) made the first extragalacticExpand
Qso 0130-4021: a third qso showing a low deuterium to hydrogen abundance ratio
We have discovered a third quasar absorption system which is consistent with a low deuterium-to-hydrogen abundance ratio, D/H = 3.4 × 10-5. The zabs ~ 2.8 partial Lyman limit system toward Q0130-4021Expand
Molecular hydrogen, deuterium and metal abundances in the damped Ly-alpha system at z = 3.025 toward QSO 0347-3819
We have detected in high-resolution spectra of the quasar Q0347-3819 obtained with the UV-Visual Echelle Spectrograph (UVES) at the VLT/Kueyen telescope over 80 absorption features in the Lyman andExpand
Deuterium toward Quasar Q0014+813
We present new Keck telescope spectra of the first QSO claimed to show deuterium absorption: Q0014+813. Improved signal on the Lyman series absorption lines gives more accurate information on theExpand
New Hubble Space Telescope Spectra of QSO PG 1718+4807: No Evidence for Strong Deuterium Absorption*
The zabs ~ 0.701 absorption system toward QSO PG 1718+4807 is the only example of a QSO absorption system which might have a deuterium/hydrogen ratio approximately 10 times the value found towardExpand
Deuterium at high redshift: Primordial or evolved?
On the basis of arguments from galactic chemical evolution we suggest that the recent observations of D=H vs. metallicity in several high redshift absorbers are best understood if the primordial DExpand