2003/11/30 by S. J. Curran, Stephen J. Curran, John K. Webb +4
Physics and Astronomy · #Abundance (ecology) #Abundance of the chemical elements #Astronomy #Astrophysics #Astrophysics and Star Formation Studies #COSMIC cancer database #Chemical evolution #Cosmology #Dark energy #Ecology #Galaxies: Formation, Evolution, Phenomena #Galaxy #Heavy element #Metric expansion of space #Molecular cloud #Physics #Population #Quasar #Stars #Stellar, planetary, and galactic studies #Universe #astro-ph
paper · pdf · doi:10.1111/j.1365-2966.2004.07958.x
published as Mon.Not.Roy.Astron.Soc. 351 (2004) L24 · 5 pages, 2 figures. Accepted by MNRAS Letters. v2: Added table summarizing H2-bearing DLA properties, added figure showing [Fe/H] vs. redshift, added more discussion
arxiv created 2004/04/27 · openalex publication_date 2004/06/01 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
Spectroscopic observations of distant quasars have resulted in the detection of molecular hydrogen in intervening damped Lyman α absorption clouds (DLAs). We use observations compiled from different experimental groups to show that the molecular hydrogen abundance exhibits a dramatic increase over a cosmological time period corresponding to 13 to 24 per cent of the age of the Universe. We also tentatively show that the heavy-element abundances in the same gas clouds exhibit a faster and more well-defined cosmological evolution compared with the general DLA population over the same time baseline. We argue that this latter point is unsurprising, because the general DLA population arises in a wide variety of galaxy types and environments, and thus a spans broad range of ISM gas-phases and abundances at the same cosmic time. DLAs exhibiting H2 absorption may therefore circumvent this problem, efficiently identifying a narrower class of objects, and provide a more sensitive probe of cosmological chemical evolution.