Volume 491, Number 2, November IV 2008
|Page(s)||397 - 400|
|Section||Cosmology (including clusters of galaxies)|
|Published online||01 October 2008|
HD molecules at high redshift*
A low astration factor of deuterium in a solar-metallicity DLA system at z = 2.418
Institut d'Astrophysique de Paris, CNRS - Université Pierre et Marie Curie, 98bis Bd Arago, 75014 Paris, France e-mail: [noterdaeme;petitjean]@iap.fr
2 European Southern Observatory, Alonso de Córdova 3107, Casilla 19001, Vitacura, Santiago 19, Chile e-mail: firstname.lastname@example.org
3 Inter University Centre for Astronomy and Astrophysics, Post Bag 4, Ganesh Khind, Pune 411 007, India e-mail: email@example.com
4 Ioffe Physical Technical Institute, St Petersburg 194021, Russia e-mail: firstname.lastname@example.org
Accepted: 20 September 2008
We present the detection of deuterated molecular hydrogen (HD) in the remote Universe in a damped Lyman-α cloud at toward the quasar SDSS J143912.04+111740.5. This is a unique system in which H2 and CO molecules are also detected. The chemical enrichment of this gas derived from Zn ii and S ii is as high as in the Sun. We measure , which is significantly higher than the same ratio measured in the Galaxy and close to the primordial D/H ratio estimated from the WMAP constraint on the baryonic matter density (). This indicates a low astration factor of deuterium that contrasts with the unusually high chemical enrichment of the gas. This can be interpreted as the consequence of an intense infall of primordial gas onto the associated galaxy. Detection of HD molecules at high-z also opens the possibility of obtaining an independent constraint on the cosmological-time variability of μ, the proton-to-electron mass ratio.
Key words: cosmology: observations / galaxies: high-redshift / galaxies: ISM / quasars: absorption lines / quasars: individual: SDSS J143912.04+111740.5
© ESO, 2008
Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.
Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.
Initial download of the metrics may take a while.