Journal Article

Metal abundances at <i>z</i> < 1.5: new measurements in sub-damped Lyman α absorbers*

C. Péroux, J. D. Meiring, V. P. Kulkarni, P. Khare, J. T. Lauroesch, G. Vladilo and D. G. York

in Monthly Notices of the Royal Astronomical Society

Published on behalf of The Royal Astronomical Society

Volume 386, issue 4, pages 2209-2220
Published in print June 2008 | ISSN: 0035-8711
Published online April 2008 | e-ISSN: 1365-2966 | DOI: http://dx.doi.org/10.1111/j.1365-2966.2008.13186.x
Metal abundances at z < 1.5: new measurements in sub-damped Lyman α absorbers*

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Damped Lyman α systems (DLAs) and sub-DLAs seen towards background quasars provide the most detailed probes of elemental abundances. Somewhat paradoxically these measurements are more difficult at lower redshifts due to the atmospheric cut-off, and so a few years ago our group began a program to study abundances at z < 1.5 in quasar absorbers. In this paper, we present new Ultraviolet and Visual Echelle Spectrograph (UVES) observations of six additional quasar absorption-line systems at z < 1.5, five of which are sub-DLAs. We find solar or above solar metallicity, as measured by the abundance of zinc, assumed not to be affected by dust, in two sub-DLAs: one, towards Q0138−0005 with [Zn/H]=+0.28 ± 0.16; the other towards Q2335+1501 with [Zn/H]=+0.07 ± 0.34. Relatively high metallicity was observed in another system: Q0123−0058 with [Zn/H]=−0.45 ± 0.20. Only for the one DLA in our sample, in Q0449−1645, do we find a low metallicity, [Zn/H]=−0.96 ± 0.08. We also note that in some of these systems large relative abundance variations from component to component are observed in Si, Mn, Cr and Zn.

Keywords: galaxies: abundances; intergalactic medium; quasars: absorption lines; quasars: general

Journal Article.  7324 words.  Illustrated.

Subjects: Astronomy and Astrophysics

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