The Cosmological Baryon Density from the Deuterium-to-Hydrogen Ratio in QSO Absorption Systems: D/H toward Q1243+3047

By D. Kirkman, D. Tytler, N. Suzuki, John M. O’Meara, D. Lubin. 2003

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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 of the continuum level and the amount of D absorption in a minor second component. The measured D/H is likely the primordial value because [O/H] = -2.79 ± 0.05. This absorption system has a neutral hydrogen column density log N = 19.73 ± 0.04 cm-2, shows five D lines, and is mostly ionized. The best estimate of the primordial D/H is 2.78 × 10-5, from the log D/H-values toward five QSOs. The dispersion in the five values is larger than we expect from their individual measurement errors, and we suspect this is because some of these errors were underestimated. We observe a trend in D/H with log N that we also suspect is spurious. The best value for D/H is 0.6 σ smaller than we quoted in O'Meara et al. from three QSOs, and although we have more values, the error is similar because the dispersion is larger. In standard big bang nucleosynthesis (SBBN), the best D/H corresponds to a baryon-to-photon ratio η = 5.9 ± 0.5 × 10-10 and gives precise predictions for the primordial abundances of the other light nuclei. We predict more 4He than is reported in most measurements, although not more than allowed by some estimates of the systematic errors. We predict a 3He abundance very similar to that reported by Bania et al., and we predict 3-4 times more 7Li than is seen in halo stars. It is unclear if those stars could have destroyed this much of their 7Li. The η-value from D/H corresponds to a cosmological baryon density Ωbh2 = 0.0214 ± 0.0020 (±9.3%), which agrees with the WMAP value of Ωbh2 = 0.0224 ± 0.001.

Subfields: Astronomy and Astrophysics, Nuclear and High Energy Physics

View Paper: https://www.semanticscholar.org/paper/41486cd06faae1d1c37c9c09774965aef0c46e03

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Citations in the corpus

The Observed Growth of Massive Galaxy Clusters I: Statistical Methods and Cosmological Constraints (2009, methodology): “…of the XLF data, we also use Gaussian priors to constrain the Hubble parameter and the mean baryon density, based on the results of the Hubble Key project (h = H0/100 km s−1 Mpc−1 = 0.72 ± 0.08, Freedman et al. 2001) and big bang nucleosynthesis studies ( bh2 = 0.0214 ± 0.002, Kirkman et al. 2003).”
One Percent Determination of the Primordial Deuterium Abundance (2017, methodology): “The best-fitting model profile has an H i column density of log10 N (H i)/cm −2 = 19.761 ± 0.026, which is in good agreement with the corresponding estimate reported by Kirkman et al. (2003), 19.73 ± 0.04.”
GALAXY CLUSTERS DISCOVERED VIA THE SUNYAEV–ZEL’DOVICH EFFECT IN THE FIRST 720 SQUARE DEGREES OF THE SOUTH POLE TELESCOPE SURVEY (2012, methodology): “Finally, we sometimes use a BBN prior on the baryon density from measurements of the abundances of deuterium (Kirkman et al. 2003).”
New constraints on dark energy from the observed growth of the most X-ray luminous galaxy clusters (2007, methodology): “In addition to the assumption of spatial flatness, we adopt the Gaussian priors h = 0.72 ± 0.08 (Freedman et al. 2001) and Ωbh 2 = 0.0214±0.002 (Kirkman et al. 2003) from the Hubble Key Project and Big Bang nucleosynthesis studies, respectively.”
A Realistic Determination of the Error on the Primordial Helium Abundance: Steps toward Nonparametric Nebular Helium Abundances (2004, methodology): “The D/H prediction is in excellent agreement with the average of the five best determined quasar absorption system abundances (Burles & Tytler 1998a, 1998b; O’Meara et al. 2001; Pettini & Bowen 2001; Kirkman et al. 2003), which give1 D=H ¼ (2:78 0:29) ; 10 5 (see Fig.”
A kinematical approach to dark energy studies (2006, background): “…priors on the present value of the Hubble parameter H0 = 72 ± 8 km(s Mpc)−1 (Freedman et al. 2001), the mean baryon density Ωbh 2 = 0.0214±0.0020 (Kirkman et al. 2003) and the X-ray bias factor b = 0.824±0.089 [determined from the hydrodynamical simulations of Eke et al. (1998), including a…”
COSMOLOGICAL CONSTRAINTS FROM SUNYAEV–ZEL'DOVICH-SELECTED CLUSTERS WITH X-RAY OBSERVATIONS IN THE FIRST 178 deg2 OF THE SOUTH POLE TELESCOPE SURVEY (2011, methodology): “Finally, we use a BBN prior from measurements of the abundances of 4He and deuterium (Kirkman et al. 2003), which we include as a Gaussian prior of Ωbh2 = 0.022 ± 0.002.”
Systematic Effects and a New Determination of the Primordial Abundance of 4He and dY/dZ from Observations of Blue Compact Galaxies (2003, background): “These values are lower at the 2 level than bh 2 ¼ 0:021 0:002 from recent measurements of the deuterium abundance in damped Ly systems (Kirkman et al. 2003).”