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Journal articles on the topic 'Deuterium abundance'

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Published: 4 June 2021

Last updated: 5 February 2022

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1

Prodanović, Tijana, Gary Steigman, and Brian D. Fields. "(Un)true deuterium abundance in the Galactic disk." Proceedings of the International Astronomical Union 5, S268 (November 2009): 65–70. http://dx.doi.org/10.1017/s1743921310003881.

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AbstractDeuterium has a special place in cosmology, nuclear astrophysics, and galactic chemical evolution, because of its unique property that it is only created in the big bang nucleosynthesis while all other processes result in its net destruction. For this reason, among other things, deuterium abundance measurements in the interstellar medium (ISM) allow us to determine the fraction of interstellar gas that has been cycled through stars, and set constraints and learn about different Galactic chemical evolution (GCE) models. However, recent indications that deuterium might be preferentially depleted onto dust grains complicate our understanding about the meaning of measured ISM deuterium abundances. For this reason, recent estimates by Linsky et al. (2006) have yielded a lower bound to the “true”, undepleted, ISM deuterium abundance that is very close to the primordial abundance, indicating a small deuterium astration factor contrary to the demands of many GCE models. To avoid any prejudice about deuterium dust depletion along different lines of sight that are used to determine the “true” D abundance, we propose a model-independent, statistical Bayesian method to address this issue and determine in a model-independent manner the undepleted ISM D abundance. We find the best estimate for the gas-phase ISM deuterium abundance to be (D/H)ISM ≥ (2.0 ± 0.1) × 10−5. Presented are the results of Prodanović et al. (2009).

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2

Scully, Sean Thomas, and Keith A. Olive. "The Deuterium Abundance and Nucleocosmochronology." Astrophysical Journal 446 (June 1995): 272. http://dx.doi.org/10.1086/175786.

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3

Ramadurai, S. "Population III Objects and Lithium Abundance." Publications of the Astronomical Society of Australia 9, no. 1 (1991): 138. http://dx.doi.org/10.1017/s132335800002525x.

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AbstractThe earlier work on the production of deuterium in the accretion tori around Population III objects has been criticised on the basis of relative production ratios of deuterium, helium-3 and 7Li. It is shown here that the criticism on the basis of helium-3 over-production is unjustified, as no measurement of helium-3 and lithium abundances for the same stars is available. It is predicted that indeed the helium-3 abundance determination will be the best means to verify the original hypothesis.

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4

L. Linsky, Jeffrey, and Brian E. Wood. "Deuterium Abundance in the Local ISM." Symposium - International Astronomical Union 187 (2002): 75–79. http://dx.doi.org/10.1017/s0074180900113762.

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Excellent HST/GHRS spectra of interstellar hydrogen and deuterium Lyman-α absorption toward nearby stars allow us to identify systematic errors that have plagued earlier work and to measure accurate values of the D/H ratio in local interstellar gas. Analysis of 12 sightlines through the Local Interstellar Cloud leads to a mean value of D/H = (1.50 ± 0.10) x 10−5 with all data points lying within ±1σ of the mean. Deciding whether or not the D/H ratio has different values elsewhere in the Galaxy and beyond will be one of the major objectives of the FUSE mission.

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5

Poupko, R., Z. Olender, D. Reichert, and Z. Luz. "Deuterium MAS NMR in Natural Abundance." Journal of Magnetic Resonance, Series A 106, no. 1 (January 1994): 113–15. http://dx.doi.org/10.1006/jmra.1994.1010.

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6

Ramadurai, S., and M. J. Rees. "Deuterium abundance and Population III remnants." Monthly Notices of the Royal Astronomical Society 215, no. 1 (July 1, 1985): 53P—56P. http://dx.doi.org/10.1093/mnras/215.1.53p.

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7

Burles, Scott, and David Tytler. "The Deuterium Abundance toward Q1937−1009." Astrophysical Journal 499, no. 2 (June 1998): 699–712. http://dx.doi.org/10.1086/305667.

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8

Vanýsek, Vladimír, and Petr Vanýsek. "Prediction of deuterium abundance in comets." Icarus 61, no. 1 (January 1985): 57–59. http://dx.doi.org/10.1016/0019-1035(85)90154-x.

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9

Pitrou, Cyril, Alain Coc, Jean-Philippe Uzan, and Elisabeth Vangioni. "A new tension in the cosmological model from primordial deuterium?" Monthly Notices of the Royal Astronomical Society 502, no. 2 (January 20, 2021): 2474–81. http://dx.doi.org/10.1093/mnras/stab135.

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ABSTRACT Recent measurements of the D(p,γ)3He nuclear reaction cross-section and of the neutron lifetime, along with the reevaluation of the cosmological baryon abundance from cosmic microwave background (CMB) analysis, call for an update of abundance predictions for light elements produced during the big-bang nucleosynthesis (BBN). While considered as a pillar of the hot big-bang model in its early days, BBN constraining power mostly rests on deuterium abundance. We point out a new ≃1.8σ tension on the baryonic density, or equivalently on the D/H abundance, between the value inferred on one hand from the analysis of the primordial abundances of light elements and, on the other hand, from the combination of CMB and baryonic oscillation data. This draws the attention on this sector of the theory and gives us the opportunity to reevaluate the status of BBN in the context of precision cosmology. Finally, this paper presents an upgrade of the BBN code primat.

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10

S. Friaça, Amancio C. "Implications of Early Cooling Flows and Galactic Winds for the Evolution of Deuterium." Symposium - International Astronomical Union 198 (2000): 535–39. http://dx.doi.org/10.1017/s0074180900167282.

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The deuterium abundances in high-redshift QSO absorption-line systems could be an important constraint in models of galaxy formation. Here we investigate the role of galactic winds and massive cooling flows present during the formation of galaxies on the evolution of deuterium abundance. Destruction factors are calculated and the time and spatial scales for the dispersal through galactic winds of the processed deuterium-depleted gas are presented and related to the D/H determinations for QSO absorption-line systems. The calculations are derived from a chemodynamical model within a scenario in which the absorbers are located inside the hot halo of a young galaxy.

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11

Burles, Scott, and David Tytler. "The Deuterium Abundance toward QSO 1009+2956." Astrophysical Journal 507, no. 2 (November 10, 1998): 732–44. http://dx.doi.org/10.1086/306341.

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12

Cooke, Ryan, and Max Pettini. "The primordial abundance of deuterium: ionization correction." Monthly Notices of the Royal Astronomical Society 455, no. 2 (November 17, 2015): 1512–21. http://dx.doi.org/10.1093/mnras/stv2343.

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13

Davis, Timothy A., and Freeke van de Voort. "Stellar initial mass function variation in massive early-type galaxies: the potential role of the deuterium abundance." Monthly Notices of the Royal Astronomical Society 498, no. 3 (September 7, 2020): 4051–59. http://dx.doi.org/10.1093/mnras/staa2679.

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ABSTRACT The observed stellar initial mass function (IMF) appears to vary, becoming bottom-heavy in the centres of the most massive, metal-rich early-type galaxies. It is still unclear what physical processes might cause this IMF variation. In this paper, we demonstrate that the abundance of deuterium in the birth clouds of forming stars may be important in setting the IMF. We use models of disc accretion on to low-mass protostars to show that those forming from deuterium-poor gas are expected to have zero-age main-sequence masses significantly lower than those forming from primordial (high deuterium fraction) material. This deuterium abundance effect depends on stellar mass in our simple models, such that the resulting IMF would become bottom-heavy – as seen in observations. Stellar mass loss is entirely deuterium free and is important in fuelling star formation across cosmic time. Using the Evolution and Assembly of GaLaxies and their Environments (EAGLE) simulation we show that stellar mass-loss-induced deuterium variations are strongest in the same regions where IMF variations are observed: at the centres of the most massive, metal-rich, passive galaxies. While our analysis cannot prove that the deuterium abundance is the root cause of the observed IMF variation, it sets the stage for future theoretical and observational attempts to study this possibility.

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14

Tatner, P. "Deuterium and oxygen-18 abundance in birds: implications for DLW energetics studies." American Journal of Physiology-Regulatory, Integrative and Comparative Physiology 258, no. 3 (March 1, 1990): R804—R812. http://dx.doi.org/10.1152/ajpregu.1990.258.3.r804.

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The doubly labeled water (DLW) technique for measuring energy expenditure may employ one (18O) or two (18O and deuterium) stable isotopes as tracers. These occur naturally in the environment, so when they are used as tracers it is necessary to subtract the background levels. Few studies report data on background concentrations. This work provides such data for a range of avian species. Overall, there was a strong positive correlation (r = 0.63) between the 18O and deuterium concentrations in birds' body water. Variation in the deuterium concentration was less extensive than in the 18O concentration (1:2.7 parts/million). In the European robin, there was a linked, seasonal variation in 18O and deuterium abundance producing high summer and low winter values. Throughout the year, a high individual variability was greater in 18O than in deuterium. A difference between the European robin and the dipper suggests that habitat may also influence background abundance. Investigation of the effect of variation in background abundance on measures of energy expenditure for small passerines (20 g) revealed that employing estimates, instead of direct measurements, had a minor influence over an experimental period of 1 day but could potentially introduce errors as large as 54% over a 2-day period.

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15

Hébrard, G., D. Péquignot, J. R. Walsh, C. Morisset, A. Vidal-Madjar, and R. Ferlet. "Upper Limit to the Deuterium Abundance in Planetary Nebulae." Symposium - International Astronomical Union 209 (2003): 371. http://dx.doi.org/10.1017/s0074180900209030.

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We recently reported the first detection of the deuterium Balmer series in emission in H II regions, performed at the CFHT (Hébrard et al. 2000a) and at the VLT (Hébrard et al. 2000b). These narrow lines are excited by UV continuum fuorescence and arise at the atomic interface between H II regions and molecular clouds.Following this discovery, we used the CFHT with the Gecko spectrograph to observe Balmer lines in planetary nebulae. The non-detection of the deuterium Balmer lines in planetary nebulae represents the first observational evidence that this isotope was, as expected, destroyed in the parent stars.

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16

Bacmann, A., A. Faure, P. Hily-Blant, K. Kobayashi, H. Ozeki, S. Yamamoto, L. Pagani, and F. Lique. "Deuterium fractionation of nitrogen hydrides: detections of NHD and ND2." Monthly Notices of the Royal Astronomical Society 499, no. 2 (September 23, 2020): 1795–804. http://dx.doi.org/10.1093/mnras/staa2903.

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ABSTRACT Although ammonia is an abundant molecule commonly observed towards the dense interstellar medium, it has not yet been established whether its main formation route is from gas-phase ion–molecule reactions or grain-surface hydrogen additions on adsorbed nitrogen atoms. Deuterium fractionation can be used as a tool to constrain formation mechanisms. High abundances of deuterated molecules are routinely observed in the dense interstellar medium, with the ratio between deuterated molecules and the main isotopologue enhanced by several orders of magnitude with respect to the elemental D/H ratio. In the case of ammonia, the detection of its triply deuterated isotopologue hints at high abundances of the deuterated intermediate nitrogen radicals, ND, NHD, and ND2. So far however, only ND has been detected in the interstellar medium. In this paper, to constrain the formation of ammonia, we aim at determining the NHD/NH2 and ND2/NHD abundance ratios, and compare them with the predictions of both pure gas-phase and grain-surface chemical models. We searched for the fundamental rotational transitions of NHD and ND2 towards the class 0 protostar IRAS16293−2422, towards which NH, NH2 and ND had been previously detected. Both NHD and ND2 are detected in absorption towards the source. The relative abundance ratios NH2:NHD:ND2 are close to 8:4:1. These ratios can be reproduced by our gas-phase chemical model within a factor of 2–3. Statistical ratios as expected from grain-surface chemistry are also consistent with our data. Further investigations of the ortho-to-para ratio in ND2 , both theoretical and observational, could bring new constraints to better understand nitrogen hydride chemistry.

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17

Landsman, Wayne. "White Dwarf Probes of Interstellar Deuterium." Symposium - International Astronomical Union 198 (2000): 485–86. http://dx.doi.org/10.1017/s0074180900167117.

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We review the advantages of using hot white dwarfs (WDs) as probes of the deuterium abundance in the local interstellar medium. We then discuss advantages of the Space Telescope Imaging Spectrograph (STIS) for such observations, as compared with earlier observations with the Goddard High Resolution Spectrograph (GHRS). The GHRS Ly α profile of the white dwarf HZ 43 is probably modified by the hot ‘hydrogen wall’ surrounding the Sun; but despite this complication, the sightline remains a promising one for an accurate determination of the deuterium abundance in the local interstellar medium.

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18

Hébrard, Guillaume. "What the D/O ratio tells us about the interstellar abundance of deuterium?" Proceedings of the International Astronomical Union 5, S268 (November 2009): 59–64. http://dx.doi.org/10.1017/s174392131000387x.

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AbstractThe ionization balances for HI, OI and DI being locked together by charge exchange, the deuterium-to-oxygen ratio is considered to be a good proxy for the deuterium-to-hydrogen ratio, in particular within the interstellar medium. As the DI and OI column densities are of similar orders of magnitude for a given sight line, comparisons of the two values are generally less subject to systematic errors than comparisons of DI and HI. Moreover, D/O is additionally sensitive to astration, because as stars destroy deuterium, they should produce oxygen. D/O measurements are now available for tens of lines of sight in the interstellar medium, most of them from FUSE observations. The D/H and D/O ratios show different pictures, D/H being clearly more dispersed than D/O. The low, homogeneous D/O ratio measured on distant lines of sight suggests a deuterium abundance representative of the present epoch that is about two times lower than this measured within the local interstellar medium.

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19

Cooke, Ryan J., Max Pettini, and Charles C. Steidel. "One Percent Determination of the Primordial Deuterium Abundance." Astrophysical Journal 855, no. 2 (March 12, 2018): 102. http://dx.doi.org/10.3847/1538-4357/aaab53.

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20

Linsky, Jeffrey L. "The Deuterium Abundance in the Local Interstellar Medium." Highlights of Astronomy 9 (1992): 455–58. http://dx.doi.org/10.1017/s1539299600009539.

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AbstractAccurate measurements of the interstellar deuterium/hydrogen ratio along different lines of sight are needed to test predictions of contemporary cosmologies. I describe our GHRS observations of the Lyman-α, 2600 Å and 2800 Å spectral regions for the spectroscopic binary system Capella, obtained with 3.57 km s resolution and high signal/noise. We are now analyzing these data to infer the column densities of H I, D I, Mg II, and Fe II along this 13 pc line of sight.

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21

Cooke, Ryan J., Max Pettini, Regina A. Jorgenson, Michael T. Murphy, and Charles C. Steidel. "PRECISION MEASURES OF THE PRIMORDIAL ABUNDANCE OF DEUTERIUM." Astrophysical Journal 781, no. 1 (January 3, 2014): 31. http://dx.doi.org/10.1088/0004-637x/781/1/31.

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22

Webb, J. K., R. F. Carswell, K. M. Lanzetta, R. Ferlet, M. Lemoine, A. Vidal-Madjar, and D. V. Bowen. "A high deuterium abundance at redshift z = 0.7." Nature 388, no. 6639 (July 1997): 250–52. http://dx.doi.org/10.1038/40814.

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23

Songaila, Antoinette, E. Joseph Wampler, and Lennox L. Cowie. "A high deuterium abundance in the early Universe." Nature 385, no. 6612 (January 1997): 137–39. http://dx.doi.org/10.1038/385137a0.

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24

Dvorkin, Irina, Elisabeth Vangioni, Joseph Silk, Patrick Petitjean, and Keith A. Olive. "Evolution of dispersion in the cosmic deuterium abundance." Monthly Notices of the Royal Astronomical Society: Letters 458, no. 1 (February 19, 2016): L104—L108. http://dx.doi.org/10.1093/mnrasl/slw028.

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25

Rugers, Martin, and Craig J. Hogan. "High Deuterium Abundance in a New Quasar Absorber." Astronomical Journal 111 (June 1996): 2135. http://dx.doi.org/10.1086/117949.

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26

Hébrard, Guillaume. "The Deuterium Balmer Series." Highlights of Astronomy 13 (2005): 811–12. http://dx.doi.org/10.1017/s1539299600017202.

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AbstractThe first detection and identification of deuterium Balmer lines were recently reported in H ii regions, using high spectral resolution data secured at CFHT and VLT. The Di lines appear as faint, narrow emission features in the blue wings of the H i Balmer lines and can be distinguished from high-velocity Hi emission. The identification as deuterium and the excitation mechanism as fluorescence are both established beyond doubt. The deuterium Balmer series might lead to a new, optical method of deuterium abundance measurement in the interstellar medium. This may be the only way to observe atomic deuterium in objects like the Magellanic Clouds or low metallicity blue compact galaxies.

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27

Butner, Harold M. "Abundance of DCO+ in Nearby Molecular Clouds." Symposium - International Astronomical Union 150 (1992): 169–70. http://dx.doi.org/10.1017/s0074180900089932.

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DCO+ is one of the most common deuterated molecules in cold (TK ~ 10 K) molecular cloud cores such as TMC-1. We report the results of a survey for DCO+ and H13CO+ emission regions among a sample of low mass cloud cores. We compare the derived DCO+/HCO+ ratio (0.046±0.014) with current chemistry models for deuterium fractionation.

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28

Dvorkin, Irina, Joseph Silk, Elisabeth Vangioni, Patrick Petitjean, and Keith A. Olive. "Dispersion in DLA metallicities and deuterium abundances." Proceedings of the International Astronomical Union 11, S321 (March 2016): 354–56. http://dx.doi.org/10.1017/s1743921316011418.

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AbstractRecent chemical abundance measurements of damped Lyman-alpha absorbers (DLAs) revealed a large intrinsic scatter in their metallicities. We discuss a semi-analytic model that was specifically designed to study this scatter by tracing the chemical evolution of the interstellar matter in small regions of the Universe with different mean density, from over- to underdense regions. It is shown that different histories of structure formation in these regions are reflected in the chemical properties of the proto-galaxies. We also address deuterium abundance measurements, which constitute a complementary probe of the star formation and infall histories.

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29

Friedman, S. D., G. Hebrard, T. M. Tripp, P. Chayer, and K. R. Sembach. "The Deuterium, Oxygen, and Nitrogen Abundance toward LSE 44." Astrophysical Journal 638, no. 2 (February 20, 2006): 847–59. http://dx.doi.org/10.1086/498969.

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30

Webb, J. K., R. F. Carswell, M. J. Irwin, and M. V. Penston. "On measuring the deuterium abundance in QSO absorption systems." Monthly Notices of the Royal Astronomical Society 250, no. 4 (June 15, 1991): 657–65. http://dx.doi.org/10.1093/mnras/250.4.657.

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31

Owen, Tobias, Jean Pierre Maillard, Catherine de Bergh, and Barry L. Lutz. "Deuterium on Mars: The Abundance of HDO and the Value of D/H." Science 240, no. 4860 (June 24, 1988): 1767. http://dx.doi.org/10.1126/science.240.4860.1767.

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Deuterium on Mars has been detected by the resolution of several Doppler-shifted lines ofHDO near 3.7 micrometers in the planet's spectrum. The ratio of deuterium to hydrogen is (9 ± 4) x 10-4; the abundance of H20 was derived from lines near 1.1 micrometers. This ratio is enriched on Mars over the teiluric value by a factor of6 ± 3. The enrichment implies that hydrogen escaped more rapidly from Mars in the past than it does now, consistent with a dense and warm ancient atmosphere on the planet.

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32

Walmsley, C. M. "Dust and the Gas Phase Composition of Dense Clouds." Symposium - International Astronomical Union 135 (1989): 263–74. http://dx.doi.org/10.1017/s0074180900125288.

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A review is given of our current knowledge of the gas phase abundance of interstellar molecules. A comparison is made between cold dust clouds, where presumably gas phase processes dominate the chemistry, and regions of high mass star formation such as Orion where both shocks and evaporation of dust grain mantles may play a role. In dust clouds, carbon rich molecules often show enhanced abundances, whereas in hot turbulent star formation regions, saturated species such as methanol and ammonia are often favored. In both types of source, there is evidence for abundance gradients and inhomogeneities. A probable cause is that the chemistry is far from a steady state situation. A useful diagnostic in such cases is the relative abundance of deuterated species and our current knowledge concerning deuterium fractionation is discussed. Recent results show that the observed degree of deuterium enhancement in species such as water, methanol, and ammonia in the Orion-KL region is much too great to be explained on the basis of normal gas phase chemistry. It is argued that a plausible explanation of the observations is that one is observing material which has recently been evaporated from dust grain mantles. One important consequence of this hypothesis is that molecular line observations may yield important information on the composition of the solid phase.

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33

Bodor, G., R. Roggeman, and J. Turk. "Variations in abundance of the molecular ion of the derivatized cocaine metabolite benzoylecgonine." Clinical Chemistry 36, no. 5 (May 1, 1990): 742–47. http://dx.doi.org/10.1093/clinchem/36.5.742.

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Abstract Benzoylecgonine (BEG) is the principal urinary metabolite of cocaine. For forensic drug testing, the presence of BEG in urine, suggested by a positive result for a screening immunoassay, must be confirmed by quantitative gas chromatographic/mass spectrometric (GC/MS) analysis, i.e., stable isotope dilution with a deuterium-labeled internal standard. GC/MS criteria for positivity also require appropriate relative abundances of qualifier ions, including the molecular ion, but there is little published information on the observed absolute values for qualifier ion ratios or on the variability of these values. This lack of information creates uncertainty for laboratories initiating programs testing urine for drugs of abuse as to performance criteria for run acceptability and sample positivity. We have observed substantial variability (CV = 50%) in the abundance of the molecular ion of derivatized BEG relative to the base ion in reference materials. This variability can result in a high rate of repetition of runs and generate confusion in the defense of forensic drug-testing results. Normalization of the abundance of the molecular ion of derivatized BEG to that of the deuterium-labeled internal standard in the same sample greatly reduces the apparent variability in this measurement; it is also more reliable than the absolute value of the relative abundance of the molecular ion in determining run acceptability and positive or negative results for a sample.

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34

Ferlet, R. "Deuterium in the Diffuse Interstellar Medium." Symposium - International Astronomical Union 150 (1992): 85–90. http://dx.doi.org/10.1017/s0074180900089750.

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We review the observational status in evaluating the interstellar deuterium abundance and show that the most reasonable value is of the order of 10−5. Although in general agreement with the standard Big Bang nucleosynthesis, the situation is still unclear and deserves much more observations.

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35

Schramm, D. N. "Big Bang Nucleosynthesis." Symposium - International Astronomical Union 187 (2002): 1–15. http://dx.doi.org/10.1017/s0074180900113695.

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Big Bang Nucleosynthesis (BBN) is on the verge of undergoing a transformation now that extragalactic deuterium is being measured. Previously, the emphasis was on demonstrating the concordance of the Big Bang Nucleosynthesis model with the abundances of the light isotopes extrapolated back to their primordial values using stellar and Galactic evolution theories. Once the primordial deuterium abundance is converged upon, the nature of the field will shift to using the much more precise primordial D/H to constrain the more flexible stellar and Galactic evolution models (although the question of potential systematic error in 4He abundance determinations remains open). The remarkable success of the theory to date in establishing the concordance has led to the very robust conclusion of BBN regarding the baryon density. The BBN constraints on the cosmological baryon density are reviewed and demonstrate that the bulk of the baryons are dark and also that the bulk of the matter in the universe is non-baryonic. Comparison of baryonic density arguments from Lyman-α clouds, x-ray gas in clusters, the Sunyaev-Zeldovich effect, and the microwave anisotropy are made and shown to be consistent with the BBN value.

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36

Lubowich, Donald, and Jay M. Pasachoff. "The Galactic deuterium gradient." Proceedings of the International Astronomical Union 5, S268 (November 2009): 179–80. http://dx.doi.org/10.1017/s1743921310004072.

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AbstractThe Galactic deuterium abundance gradient has been determined from observations of DCN in Galactic molecular clouds. This is the only way to observe D throughout the Galaxy because the molecular clouds are not limited to the 2 kpc region around the Sun observed with FUSE and from DI. We used an astrochemistry model and the DCN/HCN ratios to estimate the underlying D/H ratios in 16 molecular clouds including five in the Galactic Center. The resulting positive Galactic D gradient and reduced Galactic Center D/H ratio imply that there are no significant Galactic sources of D, there is continuous infall of low-metallicity gas into the Galaxy, and that deuterium is cosmological.

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37

Hébrard, G., A. Vidal-Madjar, R. Ferlet, C. Mallouris, D. York, and M. Lemoine. "Interstellar D/H on the Sightline of Sirius." Symposium - International Astronomical Union 198 (2000): 236–37. http://dx.doi.org/10.1017/s007418090016663x.

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We present observations of the binary Sirius A / Sirius B performed with HST-GHRS. Two interstellar clouds are detected on this sightline, one of them being identified as the Local Interstellar Cloud (LIC). Lyman α interstellar lines are also observed, but whereas the deuterium Lyman α line is well detected in the LIC with an abundance in agreement with that obtained by Linsky et al. (1995), no significant D i line is detected in the second cloud. The deuterium abundance which we measured in this cloud is 0 < (D/H)ism < 1-6 × 10−5. Despite the large error bar, this sightline appears consequently as a good candidate for a low (D/H)ism.

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38

Carney, M. T., D. Fedele, M. R. Hogerheijde, C. Favre, C. Walsh, S. Bruderer, A. Miotello, et al. "Probing midplane CO abundance and gas temperature with DCO+ in the protoplanetary disk around HD 169142." Astronomy & Astrophysics 614 (June 2018): A106. http://dx.doi.org/10.1051/0004-6361/201732384.

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Context. Physical and chemical processes in protoplanetary disks affect the disk structure and the midplane environment within which planets form. The simple deuterated molecular cation DCO+ has been proposed to act as a tracer of the disk midplane conditions. Aims. This work aims to understand which midplane conditions are probed by the DCO+ emission in the disk around the Herbig Ae star HD 169142. We explore the sensitivity of the DCO+ formation pathways to gas temperature and CO abundance. Methods. The DCO+ J = 3−2 transition was observed with Atacama Large Millimeter/submillimeter Array at a spatial resolution of ~0.3′′ (35 AU at 117 pc). We modeled the DCO+ emission in HD 169142 with a physical disk structure adapted from the literature, and employed a simple deuterium chemical network to investigate the formation of DCO+ through the cold deuterium fractionation pathway via H2D+. Parameterized models are used to modify the gas temperature and CO abundance structure of the disk midplane to test their effect on DCO+ production. Contributions from the warm deuterium fractionation pathway via CH2D+ are approximated using a constant abundance in the intermediate disk layers. Results. The DCO+ line is detected in the HD 169142 disk with a total integrated line flux of 730 ± 73 mJy km s−1. The radial intensity profile reveals a warm, inner component of the DCO+ emission at radii ≲30 AU and a broad, ring-like structure from ~50–230 AU with a peak at 100 AU just beyond the edge of the millimeter grain distribution. Parameterized models show that alterations to the midplane gas temperature and CO abundance are both needed to recover the observed DCO+ radial intensity profile. The alterations are relative to the fiducial physical structure of the literature model constrained by dust and CO observations. The best-fit model contains a shadowed, cold midplane in the region z∕r < 0.1 with an 8 K decrease in Tgas and a factor of five CO depletion just beyond the millimeter grains (r = 83 AU), and a 2 K decrease in Tgas for r > 120 AU. The warm deuterium fractionation pathway is implemented as a constant DCO+ abundance of 2.0 × 10−12 between 30–70 K and contributes >85% to the DCO+ emission at r < 83 AU in the best-fit model. Conclusions. The DCO+ emission probes a reservoir of cold material in the HD 169142 outer disk that is not probed by the millimeter continuum, the spectral energy distribution, nor the emission from the 12 CO, 13 CO, or C18O J = 2−1 lines. The DCO+ emission is a sensitive probe of gas temperature and CO abundance near the disk midplane and provides information about the outer disk beyond the millimeter continuum distribution that is largely absent in abundant gaseous tracers such as CO isotopologues.

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39

Romano, Donatella. "Galactic evolution of D, 3He and 4He." Proceedings of the International Astronomical Union 5, S268 (November 2009): 431–40. http://dx.doi.org/10.1017/s174392131000459x.

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AbstractThe uncertainties which still plague our understanding of the evolution of the light nuclides D, 3He and 4He in the Galaxy are described. Measurements of the local abundance of deuterium range over a factor of 3. The observed dispersion can be reconciled with the predictions on deuterium evolution from standard Galactic chemical evolution models, if the true local abundance of deuterium proves to be high, but not too high, and lower observed values are due to depletion onto dust grains. The nearly constancy of the 3He abundance with both time and position within the Galaxy implies a negligible production of this element in stars, at variance with predictions from standard stellar models which, however, do agree with the (few) measurements of 3He in planetary nebulae. Thermohaline mixing, inhibited by magnetic fields in a small fraction of low-mass stars, could in principle explain the complexity of the overall scenario. However, complete grids of stellar yields taking this mechanism into account are not available for use in chemical evolution models yet. Much effort has been devoted to unravel the origin of the extreme helium-rich stars which seem to inhabit the most massive Galactic globular clusters. Yet, the issue of 4He evolution is far from being fully settled even in the disc of the Milky Way.

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40

Levshakov, Sergei A. "The Deuterium Abundance in QSO Absorption Systems: A Mesoturbulent Approach." Symposium - International Astronomical Union 198 (2000): 135–40. http://dx.doi.org/10.1017/s0074180900166513.

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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 at za = 3.514 and 3.378 towards APM 08279+5255 are presented.

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41

Vangioni-Flam, Elisabeth, and Michel Casse. "Cosmological and astrophysical consequences of a high primordial deuterium abundance." Astrophysical Journal 441 (March 1995): 471. http://dx.doi.org/10.1086/175373.

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42

Lemoine, M., A. Vidal‐Madjar, G. Hebrard, J. ‐M Desert, R. Ferlet, A. Lecavelier des Etangs, J. C. Howk, et al. "Deuterium Abundance toward G191‐B2B: Results from the FUSE Mission." Astrophysical Journal Supplement Series 140, no. 1 (May 2002): 67–80. http://dx.doi.org/10.1086/339128.

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43

Zhang, Benli, and Maryvonne L. Martin. "Direct determination of equilibrium deuterium isotope effects at natural abundance." Journal of the American Chemical Society 114, no. 18 (August 1992): 7089–92. http://dx.doi.org/10.1021/ja00044a020.

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44

Linsky, Jeffrey L. "Accurate Measurements of the Local Deuterium Abundance from HST Spectra." Symposium - International Astronomical Union 168 (1996): 529–32. http://dx.doi.org/10.1017/s0074180900110599.

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An accurate measurement of the primordial value of D/H would provide a critical test of nucleosynthesis models for the early universe and the baryon density. I briefly summarize the ongoing HST observations of the interstellar H and D Lyman-α absorption for lines of sight to nearby stars and comment on recent reports of extragalactic D/H measurements.

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45

Krasnopolsky, V. "On the Deuterium Abundance on Mars and Some Related Problems." Icarus 148, no. 2 (December 2000): 597–602. http://dx.doi.org/10.1006/icar.2000.6534.

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46

Pettini, Max, and Ryan Cooke. "A new, precise measurement of the primordial abundance of deuterium." Monthly Notices of the Royal Astronomical Society 425, no. 4 (August 30, 2012): 2477–86. http://dx.doi.org/10.1111/j.1365-2966.2012.21665.x.

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47

Deal, M., and C. J. A. P. Martins. "Primordial nucleosynthesis with varying fundamental constants." Astronomy & Astrophysics 653 (September 2021): A48. http://dx.doi.org/10.1051/0004-6361/202140725.

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The success of primordial nucleosynthesis has been limited by the long-standing lithium problem. We use a self-consistent perturbative analysis of the effects of the relevant theoretical parameters on primordial nucleosynthesis, including variations of nature’s fundamental constants, to explore the problem and its possible solutions in the context of the latest observations and theoretical modeling. We quantify the amount of depletion needed to solve the lithium problem, and show that transport processes of chemical elements in stars are able to account for it. Specifically, the combination of atomic diffusion, rotation, and penetrative convection allows us to reproduce the lithium surface abundances of Population II stars, starting from the primordial lithium abundance. We also show that even with this depletion factor, a preference for a value of the fine-structure constant at this epoch remains that is larger than the value currently obtained in the laboratory by a few parts per million of relative variation at a statistical significance level of two to three standard deviations. This preference is driven by the recently reported discrepancy between the best-fit values for the baryon-to-photon ratio (or equivalently, the Deuterium abundance) inferred from cosmic microwave background and primordial nucleosynthesis analyses, and is largely insensitive to the Helium-4 abundance. We thus conclude that the lithium problem most likely has an astrophysical solution, while the Deuterium discrepancy provides a possible indication of new physics.

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48

Pascal, Robert A., Mary W. Baum, Carol K. Wagner, Lauren R. Rodgers, and Ded Shih Huang. "Measurement of deuterium kinetic isotope effects in organic and biochemical reactions by natural abundance deuterium NMR spectroscopy." Journal of the American Chemical Society 108, no. 21 (October 1986): 6477–82. http://dx.doi.org/10.1021/ja00281a005.

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49

Vanysek, V. "Isotopic Ratios in Comets." International Astronomical Union Colloquium 116, no. 2 (1991): 879–95. http://dx.doi.org/10.1017/s0252921100012756.

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Abstract.The isotopic abundances depend on the universal evolution of elements and on the individual history of particular objects. Since it is believed that unprocessed material of the solar nebula is preserved in comets, the data concerning the abundance of stable isotopes in these primitive bodies are of some importance in the cosmological context. The present status of this problem is reviewed. The reliability of results for nuclear species with cosmological and cosmogonical implications, such as D/H, C 12/13, N 14/15, O 16/18, and Mg 24/25/26, is discussed. Significant variation is found for the isotopic abundance of carbon, depending upon which carbon reservoir is sampled. Deuterium is probably enhanced relative to the interstellar ratio. For other isotopes, the ratios are close to those of the terrestrial data. The tendency of the D/H ratio to be at higher values indicates a low temperature in the environment of the comet’s formation, and, together with similar effects in the outer planets, suggests that there were two different primordial reservoirs of deuterium in the solar system. The 12C/13C ratio inferred from in situ mass spectrometry of the dust, as well as from the ground-based optical spectra of the Swan band, tends to be approximately equal to the average terrestrial ratio (89) or larger. Recent results obtained from the CN band provide a significantly lower value (about 65), which corresponds to the carbon isotopic ratio in the diffuse interstellar clouds. The enhancement of deuterium and the possible differences of the carbon isotopic ratio in different species and refractory material are indicative of chemical fractionation processes in the protosolar nebula.

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50

Hansen, Poul Erik. "Deuterium Isotope Effects on 14,15N Chemical Shifts of Ammonium Ions: A Solid State NMR Study." International Journal of Inorganic Chemistry 2011 (December 27, 2011): 1–4. http://dx.doi.org/10.1155/2011/696497.

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Deuterium isotope effects on N14,15 chemical shifts are measured in ammonium halides in the solid state using both enriched N15 salts and N14 natural abundance materials. The effects are correlated to N15 chemical shifts and to N···X distances. The deuterium isotope effects on N14,15 chemical shifts in the solid state are discussed in relation to effects observed in solution. No NH couplings are seen due to fast rotation in the solid, which leads to self-decoupling, whereas ND couplings are present.

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