The Deuterium to Hydrogen Abundance Ratio toward a Fourth QSO: HS 0105+1619

O’Meara, John M.; Tytler, David; Kirkman, David; Suzuki, N.; Prochaska, J. Xavier; Lubin, Dan; Wolfe, Arthur M.

doi:10.1086/320579

Cited by 312 publications

(209 citation statements)

References 37 publications

(30 reference statements)

Supporting

Mentioning

179

Contrasting

Unclassified

Order By: Relevance

“…This figure differs slightly from the family of allowed solutions given in [24] in that we have adopted the newer D/H constraint from [39] Figure 1 will be adopted as weak top-hat priors in the CMB likelihood analysis described below. These regions include both the uncertainties from the abundance constraints described above and the uncertainties in the BBN model predictions [42].…”

Section: Neutrino-degenerate Bbnmentioning

confidence: 96%

Constraints on neutrino degeneracy from the cosmic microwave background and primordial nucleosynthesis

et al. 2002

View full text Add to dashboard Cite

We reanalyze the cosmological constraints on the existence of a net universal lepton asymmetry and neutrino degeneracy based upon the latest high resolution CMB sky maps from BOOMERANG, DASI, and MAXIMA-1. We generate likelihood functions by marginalizing over (Ω b h 2 , ξν µ,τ , ξν e , ΩΛ, h, n) plus the calibaration uncertainties. We consider flat ΩM + ΩΛ = 1 cosmological models with two identical degenerate neutrino species, ξν µ,τ ≡ |ξν µ | = |ξν τ | and a small ξν e . We assign weak top-hat priors on the electron-neutrino degeneracy parameter ξν e and Ω b h 2 based upon allowed values consistent with the nucleosynthesis constraints as a function of ξν µ,τ . The change in the background neutrino temperature with degeneracy is also explicitly included, and Gaussian priors for h = 0.72±0.08 and the experimental calibration uncertainties are adopted. The marginalized likelihood functions show a slight (0.5σ) preference for neutrino degeneracy. Optimum values with two equally degenerate µ and τ neutrinos imply ξν µ,τ = 1.

show abstract

Section: Neutrino-degenerate Bbnmentioning

confidence: 96%

Constraints on neutrino degeneracy from the cosmic microwave background and primordial nucleosynthesis

et al. 2002

View full text Add to dashboard Cite

show abstract

“…If we assume that microlensing is caused by stars we have to take into account cosmological constraints on baryon density. Big Bang Nucleosynthesis (BBN) calculations together with observational data about the abundance of 2 D give the following constraints on the cosmic baryon density (O'Meara et al 2001;Burles et al 2001;Turner 2002)…”

Section: Cosmological Distribution Of Microlensesmentioning

confidence: 99%

On the contribution of microlensing to X-ray variability of high-redshifted QSOs

Popovic

Jovanović

2004

A&A

View full text Add to dashboard Cite

Abstract. We consider a contribution of microlensing to the X-ray variability of high-redshifted QSOs. Such an effect could be caused by stellar mass objects (SMO) located in a bulge or/and in a halo of this quasar as well as at cosmological distances between an observer and a quasar. Here, we not consider microlensing caused by deflectors in our Galaxy since it is wellknown from recent MACHO, EROS and OGLE observations that the corresponding optical depth for the Galactic halo and the Galactic bulge is lower than 10 −6 . Cosmologically distributed gravitational microlenses could be localized in galaxies (or even in bulge or halo of gravitational macrolenses) or could be distributed in a uniform way. We have analyzed both cases of such distributions. As a result of our analysis, we obtained that the optical depth for microlensing caused by stellar mass objects is usually small for quasar bulge and quasar halo gravitational microlens distributions (τ ∼ 10 −4 ). On the other hand, the optical depth for gravitational microlensing caused by cosmologically distributed deflectors could be significant and could reach 10 −2 −0.1 at z ∼ 2. This means that cosmologically distributed deflectors may contribute significantlly to the X-ray variability of high-redshifted QSOs (z > 2). Considering that the upper limit of the optical depth (τ ∼ 0.1) corresponds to the case where dark matter forms cosmologically distributed deflectors, observations of the X-ray variations of unlensed QSOs can be used for the estimation of the dark matter fraction of microlenses.

show abstract

“…The findings have important implications for our assessment of the total baryon density in the universe (Boesgaard & Steigman 1985;Walker et al 1991), but this goal has been elusive because various determinations seem to disagree with each other (and weaknesses in some have been pointed out; Lemoine et al 1999;O'Meara et al 2001;Pettini & Bowen 2001;Moos et al 2002). We now ask, '' can we measure D/H in the system at z abs ¼ 0:08093 in front of PHL 1811? ''…”

Section: Properties Of the Extragalactic Absorbing Systemsmentioning

confidence: 99%

Absorption-Line Systems and Galaxies in Front of the Second-brightest Quasar, PHL 1811

et al. 2003

View full text Add to dashboard Cite

The extraordinarily bright quasar PHL 1811, at a redshift z em ¼ 0:192, provides an attractive opportunity to use ultraviolet absorption-line spectroscopy to study the properties of gas systems in the local universe. A short (11.3 ks), exploratory spectrum of this object was obtained by the Far Ultraviolet Spectroscopic Explorer (FUSE) with a signal-to-noise ratio of 20 per /20,000 resolution element over the most relevant portions of the coverage from 907 to 1185 Å . This spectrum reveals seven extragalactic absorption systems, one of which is a Lyman limit system at z abs ¼ 0:08093 with 17:5 < log NðH iÞ < 19:5. Three of the remaining systems have z abs values that differ by less than 0.008 from that of the Lyman limit system. The abundance of O with respect to Fe in the Lyman limit system is not much different from the solar abundance ratio. The opacity of the Lyman limit system below 990 Å and the numerous features arising from Galactic H 2 block a moderate fraction of important extragalactic features in the FUSE wavelength band. Nevertheless, supplementary spectra at low resolution plus a moderate-resolution, near-UV spectrum over a limited wavelength range recorded by the Space Telescope Imaging Spectrograph (STIS) on the Hubble Space Telescope helped to substantiate our identifications of systems in the FUSE spectrum. The low-resolution STIS spectrum also revealed four absorption features shortward of the quasar's Ly emission, which we interpret as arising from additional systems showing only the Ly feature. Spectroscopy of seven galaxies with M R d À 20 within approximately 2 0 of PHL 1811 indicated that two of them are near the redshift of the quasar and four have redshifts within 850 km s À1 of the extragalactic absorption systems. The Lyman limit system is likely associated with an L* galaxy at z ¼ 0:0808 lying 23 00 (34 h À1 70 kpc) from the sight line, with absorption arising in the halo of the galaxy or in an unusually large galactic disk. It is also possible that the absorbing material may be tidal debris arising from the galaxy's interactions with a neighbor lying 88 h À1 70 kpc from the sight line or more extensive intragroup or intracluster gas. Finally, in addition to prominent features at very low velocities arising from the disk of our Galaxy, the strong resonance transitions of C ii and Mg ii show evidence of material at v % À200 km s À1 ; the column densities of these two species suggest that 17:7 < log NðH iÞ < 18:1 if the material has a solar composition.

show abstract

The Deuterium to Hydrogen Abundance Ratio toward a Fourth QSO: HS 0105+1619

Cited by 312 publications

References 37 publications

Constraints on neutrino degeneracy from the cosmic microwave background and primordial nucleosynthesis

Constraints on neutrino degeneracy from the cosmic microwave background and primordial nucleosynthesis

On the contribution of microlensing to X-ray variability of high-redshifted QSOs

Absorption-Line Systems and Galaxies in Front of the Second-brightest Quasar, PHL 1811

Contact Info

Product

Resources

About