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Dust depletion and abundance pattern in damped Lyman-alpha systems: a sample of Mn and Ti abundances at z<2.2

C. Ledoux·J. Bergeron·P. Petitjean
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Abstract

We analyse a sample of 24 damped Lyman-alpha (DLA)/moderate DLA systems at 0.3 ~-0.5, the intrinsic (dust-corrected) abundance pattern of Si, Ti, Cr and Mn in DLA absorbers closely follows the trends observed in Galactic stars and these absorbers should thus have a chemical evolution similar to that of our Galaxy. At lower metallicity, some absorbers do follow the trends present in Galactic stars but a substantial fraction of them have elemental ratios (in particular [Si/Fe]dc and [Mn/Fe]dc) closer to the solar values than Galactic stars. This could be explained by a larger contribution of type Ia supernovae to the chemical enrichment of these DLA absorbers than in Galactic stars of similar metallicity. This metal-poor DLA absorber population could trace HI-rich dwarf galaxies. (Abridged)

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C. Ledoux, J. Bergeron, P. Petitjean. 2002-02-06. Dust depletion and abundance pattern in damped Lyman-alpha systems: a sample of Mn and Ti abundances at z<2.2. https://doi.org/10.1051/0004-6361%3A20020198

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