A&A 455, 835-843 (2006)
DOI: 10.1051/0004-6361:20054066

Medium-resolution spectroscopy of galaxies with redshifts 2.3 < z < 3.5

D. Mehlert^{1, 2}, C. Tapken^{1, 2}, I. Appenzeller², S. Noll³, D. de Mello^{4, 5} and T. M. Heckman<sup>6

1</sup>  Max-Planck-Institut für Astronomie, Königstuhl 17, 69117 Heidelberg, Germany
²  Landessternwarte Heidelberg, Königstuhl 12, 69117 Heidelberg, Germany
    e-mail: tapken@mpia.de
³  MPE Garching, Gießenbachstrasse, 85748 Garching, Germany
⁴  Laboratory for Astronomy and Solar Physics, GSFC, Greenbelt, MD 20771, USA
⁵  Department of Physics, Catholic University of America, DC 20064, USA
⁶  Department of Physics and Astronomy, Johns Hopkins University, Baltimore, MD 21218, USA

(Received 18 August 2005 / Accepted 12 April 2006)

Abstract
Using FORS2 at the ESO VLT we obtained medium-resolution ( ) spectra of 12 galaxies with in the FORS Deep Field. Two individual spectra with good S/N and a composite of all 12 spectra were used to derive properties of the stellar and interstellar absorption lines of galaxies in this redshift range. Systematic differences between the individual spectra were found for the strength and profiles of the intrinsic interstellar lines. For eight spectra with sufficient S/N, we measured the "1370" and "1425" metallicity indices, from which we find for our sample that galaxies at z > 3 have lower mean metallicity than galaxies at 2.3 < z < 3. However uncertainties remain concerning the absolute calibration of the metallicity tracers in use for high-redshift galaxies. Additional modeling will be needed to resolve these uncertainties.

Key words: galaxies: high-redshift -- galaxies: starburst -- galaxies: abundances -- galaxies: evolution

© ESO 2006

The OpenURL standard is a protocol for transmission of metadata describing the resource that you wish to access. An OpenURL link contains article metadata and directs it to the OpenURL server of your choice. The OpenURL server can provide access to the resource and also offer complementary services (specific search engine, export of references...). The OpenURL link can be generated by different means.

• If your librarian has set up your subscription with an OpenURL resolver, OpenURL links appear automatically on the abstract pages.
• You can define your own OpenURL resolver with your EDPS Account. In this case your choice will be given priority over that of your library.
• You can use an add-on for your browser (Firefox or I.E.) to display OpenURL links on a page (see http://www.openly.com/openurlref/). You should disable this module if you wish to use the OpenURL server that you or your library have defined.