Astronomy & Astrophysics

Issue		A&A Volume 507, Number 2, November IV 2009
Page(s)		693 - 704
Section		Extragalactic astronomy
DOI		10.1051/0004-6361/200912024
Published online		03 September 2009

A&A 507, 693-704 (2009)
DOI: 10.1051/0004-6361/200912024

The infrared emission of ultraviolet-selected galaxies from z = 0 to z = 1

V. Buat¹, T. T. Takeuchi², D. Burgarella¹, E. Giovannoli¹, and K. L. Murata³

¹ Laboratoire d'Astrophysique de Marseille, OAMP, Université Aix-Marseille, CNRS, 38 rue Frédéric Joliot-Curie, 13388 Marseille Cedex 13, France
    e-mail: [veronique.buat;denis.burgarella;elodie.giovannoli]@oamp.fr
² Institute for Advanced Research, Nagoya University, Japan
    e-mail: takeuchi@iar.nagoya-u.ac.jp
³ Division of Particle and Astrophysical Sciences, Nagoya University, Japan
    e-mail: murata.katsuhiro@g.mbox.nagoya-u.ac.jp

Received 10 March 2009 / Accepted 16 July 2009

Abstract
Aims. We want to study the IR (> $8\;\mu$ m) emission of galaxies selected on the basis of their rest-frame UV light in a very homogeneous way (wavelength and luminosity) from z = 0 to z=1. We compare their UV and IR rest-frame emission to study the evolution in dust attenuation with z as well as to check if a UV selection is capable of tracking all star formation. This UV selection will also be compared to a sample of Lyman break galaxies selected at $z \simeq 1$ .
Methods. We select galaxies in UV (1500–1800 Å) rest-frame at z=0, $z=0.6\mbox0.8$ , $z=0.8\mbox1.2$ , and with as Lyman break galaxies at $z=0.9\mbox1.3$ , the samples are compiled to sample the same range of luminosity at any redshift. The UV rest-frame data come from GALEX for z<1 and the U-band of the EIS survey (at z=1). The UV data are combined with the IRAS 60 $\mu$ m observations at z=0 and the Spitzer data at $24\;\mu$ m for z>0 sources. The evolution in the IR and UV luminosities with z is analysed for individual galaxies as well as in terms of luminosity functions.
Results. The $L_{\rm IR}/L_{\rm UV}$ ratio is used to measure dust attenuation. This ratio does not seem to evolve significantly with z for the bulk of our sample galaxies, but some trends are found for both galaxies with a strong dust attenuation and UV luminous sources: galaxies with $L_{\rm IR}/L_{\rm UV}>10$ are more frequent at z>0 than at z=0, and the largest values of $L_{\rm IR}/L_{\rm UV}$ are found for UV faint objects; in contrast, the most luminous galaxies of our samples ( $L_{\rm UV}> 2 \times 10^~L_\odot$ ), detected at z=1, exhibit a lower dust attenuation than fainter ones. The value of $L_{\rm IR}/L_{\rm UV}$ increases with the K rest-frame luminosity of the galaxies at all redshifts considered and shows a residual anticorrelation with $L_{\rm UV}$ . The most massive and UV luminous galaxies exhibit quite high specific star formation rates. Lyman break galaxies exhibit systematically lower dust attenuation than UV-selected galaxies of same luminosity, but similar specific star formation rates. The analysis of the UV + IR luminosity functions leads to the conclusion that up to z = 1, most of the star formation activity of UV-selected galaxies is emitted in IR. Although we are able to infer information about all the star formation from our UV selection at z=0.7, at z = 1 we miss a large fraction of galaxies more luminous than $\simeq$ $10^~L_{\odot}$ . The effect is found to be larger for Lyman break galaxies.

Key words: galaxies: evolution -- Galaxy: stellar content -- infrared: galaxies -- ultraviolet: galaxies

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