EDP Sciences
Free access
Issue
A&A
Volume 407, Number 1, August III 2003
Page(s) 147 - 157
Section Galactic structure and dynamics
DOI http://dx.doi.org/10.1051/0004-6361:20030840


A&A 407, 147-157 (2003)
DOI: 10.1051/0004-6361:20030840

The Building the Bridge survey for z = 3 Ly $\alpha$ emitting galaxies

I. Method and first results
J. P. U. Fynbo1, 2, 3, C. Ledoux4, P. Møller3, B. Thomsen1 and I. Burud5

1  Department of Physics and Astronomy, University of Århus, 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 by München, Germany
4  European Southern Observatory, Casilla 19001, Santiago 19, Chile
5  Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD21218, USA

(Received 17 March 2003 / Accepted 22 May 2003 )

Abstract
We present the first results of an observational programme at the ESO Very Large Telescope aimed at detecting a large sample of high-redshift galaxies fainter than the current spectroscopic limit of R=25.5 for Lyman-Break galaxies. In this paper, we describe the results of deep narrow and broad-band imaging and subsequent follow-up multi-object spectroscopy of faint high-redshift galaxies in the fields of the QSOs BRI 1346-0322 and Q 2138-4427. These QSOs have intervening high neutral hydrogen column density absorbers, at redshifts z=2.85 and z=3.15 respectively, for which redshifted Ly $\alpha$ emission falls within less than a few Å from the central wavelengths of existing VLT (~60 Å-wide) narrow-band filters. We selected 37 and 27 candidate emission-line galaxies in the two fields respectively. Most (~85%) of the candidates have R-band magnitudes fainter than R=25.5. The first spectroscopic follow-up of a sub-sample of the candidates resulted in 41 confirmed candidates and 4 foreground emission line galaxies (three [ $\ion{O}{ii}$] emitters and one $\ion{C}{iv}$ emitter). The confirmation rate for Ly $\alpha$ emitters is 82% and 68% in the field of BRI 1346-0322 and Q 2138-4427 respectively. In addition, we serendipitously detect a number of other emission-line sources on some of the slitlets not used for candidates. Of these, 9 are also most likely Ly $\alpha$ emitters with redshifts ranging from 1.98 to 3.47. The redshift distribution of confirmed candidates in the field of BRI 1346-0322 is consistent with being drawn from a uniform distribution weighted by the filter response curve, whereas the galaxies in the field of Q 2138-4427 have redshifts clustering very close to the redshift of the damped Ly $\alpha$ absorber. This latter fact indicates the existence of a large "pancake"-like structure confirming the earlier suggestions of Francis & Hewitt (1993).


Key words: cosmology: observations -- quasars: individual BRI 1346-0322, Q 2138-4427 -- galaxies: high redshift

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.