Ultraviolet-to-far infrared properties of Lyman break galaxies and luminous infrared galaxies at z ~ 1

¹ Observatoire Astronomique Marseille Provence, Laboratoire d'Astrophysique de Marseille, traverse du siphon, 13376 Marseille Cedex 12, France e-mail: [denis.burgarella;veronique.buat;tsutomu.takeuchi;sebastien.lauger]@oamp.fr
² Steward Observatory, University of Arizona, 933 North Cherry Avenue, Tucson, AZ 85721, USA e-mail: [pgperez;ktyler;grieke]@as.arizona.edu
³ Osservatorio Astronomico di Bologna, via Ranzani, 1 - 47 Bologna, Italy e-mail: olivier.ilbert1@bo.astro.it
⁴ California Institute of Technology, MC 405-47, 1200 E. California Boulevard, Pasadena, CA 91125, USA e-mail: tab@srl.caltech.edu
⁵ Center for Astrophysical Sciences, The Johns Hopkins University, 3400 North Charles St., Baltimore, MD 21218, USA e-mail: bianchi@skyrv.pha.jhu.edu
⁶ Center for Space Astrophysics, Yonsei University, Seoul 120-749, Korea e-mail: [ywlee;yi]@galaxy.yonsei.ac.kr
⁷ Observatories of the Carnegie Institution of Washington, 813 Santa Barbara Street, Pasadena 91101, USA e-mail: barry@ipac.caltech.edu
⁸ NASA/IPAC Extragalactic Database, California Institute of Technology, Mail Code 100-22, 770 S. Wilson Ave., Pasadena, CA 91125, USA
⁹ Department of Physics and Astronomy, Johns Hopkins University, 3400 North Charles Street, Baltimore, MD 21218, USA e-mail: szalay@tardis.pha.jhu.edu

Received: 5 October 2005
Accepted: 5 January 2006

Abstract

Aims.We present the first large, unbiased sample of Lyman Break Galaxies (LBGs) at . Far ultraviolet-dropout (1530 Å) galaxies in the Chandra Deep Field South have been selected using GALEX data. This first large sample in the universe provides us with a high quality reference sample of LBGs. Methods.We analyzed the sample from the UV to the IR using GALEX, SPITZER, ESO and HST data.Results.The morphology (obtained from GOODS data) of 75% of our LBGs is consistent with a disk. The vast majority of LBGs with an IR detection are also Luminous Infrared Galaxies (LIRGs). As a class, the galaxies not detected at 24 μm are an order of magnitude fainter relative to the UV compared with those detected individually, suggesting that there may be two types of behavior within the sample. For the IR-bright galaxies, there is an apparent upper limit for the UV dust attenuation and this upper limit is anti-correlated with the observed UV luminosity. Previous estimates of dust attenuations based on the ultraviolet slope are compared to new ones based on the FIR/UV ratio (for LBGs detected at 24 μm), which is usually a more reliable estimator. Depending on the calibration we use to estimate the total IR luminosity, β-based attenuations A_FUV are larger by 0.2 to 0.6 mag. than the ones estimated from FIR/UV ratio. Finally, for IR-bright LBGs, median estimated β-based SFRs are 2-3 times larger than the total SFRs estimated as while IR-based SFRs provide values below by 15-20%. We use a stacking method to statistically constrain the m flux of LBGs non individually detected. The results suggest that these LBGs do not contain large amounts of dust.