EDP Sciences
Free Access
Volume 402, Number 1, April IV 2003
Page(s) 79 - 85
Section Galactic structure and dynamics
DOI https://doi.org/10.1051/0004-6361:20030265
Published online 07 April 2003

A&A 402, 79-85 (2003)
DOI: 10.1051/0004-6361:20030265

Constraints to the evolution of Ly- $\alpha$ bright galaxies between z = 3 and z = 6

C. Maier1, K. Meisenheimer1, E. Thommes1, 2, H. Hippelein1, H. J. Röser1, J. Fried1, B. von Kuhlmann1, S. Phleps1 and C. Wolf1, 3

1  Max-Planck-Institut für Astronomie, Königstuhl 17, 69117 Heidelberg, Germany
2  Insitut für Theoretische Physik, Universität Heidelberg, 69111 Heidelberg, Germany
3  Department of Physics, Denys Wilkinson Bldg., University of Oxford, Keble Road, Oxford, OX1 3RH, UK

(Received 6 November 2002 / Accepted 4 February 2003 )

Galaxies at high redshift with a strong Ly- $\alpha$ emission line trace massive star formation in the absence of dust, and can therefore be regarded as a prime signature of the first major starburst in galaxies. We report results of the Ly- $\alpha$ search within the Calar Alto Deep Imaging Survey (CADIS). With the imaging Fabry-Perot interferometer, CADIS can detect emission lines in three waveband windows free of night-sky emission lines at 700 nm, 820 nm, and 920 nm. The typical flux detection limit for Ly- $\alpha$ emission redshifted into these windows, $F_{\rm lim} \ga 3
\times 10^{-20} ~\rm {W}\,\rm {m}^{-2}$ , corresponds to (unobscured) star formation rates of $\ga$ $ 10\, {M}_{\odot}$/yr at z=6. Candidate Ly- $\alpha$-emitting galaxies are selected from the total emission line sample, which contains more than 97% of objects at z<1.2, by the absence of flux below the Lyman limit ( B-band "dropouts"), and the non-detection of secondary emission lines in narrow band filters. We have detected 5 bright Ly- $\alpha$-emitting galaxy candidates at $z \simeq 4.8$, and 11 candidates at $z \simeq 5.7$. For two of four observed Ly- $\alpha$ candidates, one candidate at $z \simeq 4.8$ , and the other at $z \simeq 5.7$, the emission line detected with the Fabry-Perot interferometer has been verified spectroscopically at the VLT.

When compared to Ly- $\alpha$ surveys at $z\leq3.5$, even the upper limits set by our list of candidates show that bright Ly- $\alpha$ galaxies are significantly rarer at $z\ga 5$ than the assumption of a non-evolving population would predict. Therefore we conclude that the Ly- $\alpha$ bright phase of primeval star formation episodes reached its peak at redshifts 3<z<6.

Key words: galaxies: evolution -- galaxies: formation -- galaxies: high-redshift

Offprint request: C. Maier, maier@mpia-hd.mpg.de

SIMBAD Objects

© ESO 2003

Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.

Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.

Initial download of the metrics may take a while.