EDP Sciences
Free access
Volume 406, Number 3, August II 2003
Page(s) L63 - L66
Section Letters
DOI http://dx.doi.org/10.1051/0004-6361:20030931

A&A 406, L63-L66 (2003)
DOI: 10.1051/0004-6361:20030931


On the Ly $\alpha$ emission from gamma-ray burst host galaxies: Evidence for low metallicities

J. P. U. Fynbo1, 2, P. Jakobsson2, P. Møller3, J. Hjorth2, B. Thomsen1, M. I. Andersen4, A. S. Fruchter5, J. Gorosabel6, 5, S. T. Holland7, C. Ledoux8, H. Pedersen2, J. Rhoads5, M. Weidinger1 and R. A. M. J. Wijers9

1  Department of Physics and Astronomy, University of Aarhus, Ny Munkegade, 8000 Århus C, Denmark
2  Astronomical Observatory, University of Copenhagen, Juliane Maries Vej 30, 2100 Copenhagen Ø, Denmark
3  European Southern Observatory, Karl Schwarzschild-Strasse 2, 85748 Garching, Germany
4  Astrophysikalisches Institut, 14482 Potsdam, Germany
5  Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218, USA
6  Instituto de Astrofísica de Andalucía (IAA-CSIC), PO Box 03004, 18080 Granada, Spain
7  Department of Physics, University of Notre Dame, Notre Dame, IN 46556-5670, USA
8  European Southern Observatory, Casilla 19001, Santiago 19, Chile
9  University of Amsterdam, Kruislaan 403, 1098 SJ Amsterdam, The Netherlands

(Received 30 April 2003 / Accepted 19 June 2003)

We report on the results of a search for Ly $\alpha$ emission from the host galaxy of the z=2.140 GRB 011211 and other galaxies in its surrounding field. We detect Ly $\alpha$ emission from the host as well as from six other galaxies in the field. The restframe equivalent width of the Ly $\alpha$ line from the GRB 011211 host is about 21 Å. This is the fifth detection of Ly $\alpha$ emission out of five possible detections from GRB host galaxies, strongly indicating that GRB hosts, at least at high redshifts, are Ly $\alpha$ emitters. This is intriguing as only ~25% of the Lyman-Break selected galaxies at similar redshifts have Ly $\alpha$ emission lines with restframe equivalent width larger than 20 Å. Possible explanations are i) a preference for GRB progenitors to be metal-poor as expected in the collapsar model, ii) an optical afterglow selection bias against dusty hosts, and iii) a higher fraction of Ly $\alpha$ emitters at the faint end of the luminosity function for high- z galaxies. Of these, the current evidence seems to favour i).

Key words:  gamma rays: bursts -- galaxies: high redshift -- techniques: photometric

Offprint request: J. P. U. Fynbo, jfynbo@phys.au.dk

SIMBAD Objects

© ESO 2003

What is OpenURL?

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.