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The ultraviolet colours and dust attenuation of Lyman-break galaxies

Gonzalez-Perez, V.; Lacey, C.G.; Baugh, C.M.; Frenk, C.S.; Wilkins, S.M.

The ultraviolet colours and dust attenuation of Lyman-break galaxies Thumbnail


V. Gonzalez-Perez

S.M. Wilkins


Using GALFORM, a semi-analytical model of galaxy formation in the Λ cold dark matter cosmology, we study the rest-frame ultraviolet (UV) colours of Lyman-break galaxies (LBGs) in the redshift range 2.5 ≤ z ≤ 10. As the impact of dust on UV luminosity can be dramatic, our model includes a self-consistent computation of dust attenuation based on a radiative transfer model. We find that intrinsically brighter galaxies suffer stronger dust attenuation than fainter ones, though the relation has a large scatter. The model predicts galaxies with UV colours consistent with the colour selection regions designed to select LBGs in observational surveys. We find that the drop-out technique that selects LBGs based on two rest-frame UV colours is robust and effective, selecting more than 70 per cent of UV bright galaxies at a given redshift. We investigate the impact on the predicted UV colours of varying selected model parameters. We find that the UV colours are most sensitive to the modelling of dust attenuation and, in particular, to the extinction curve used in the radiative transfer calculation. If we assume a Milky Way dust extinction curve, the predicted UV continuum slopes are, in general, bluer than observed. However, we find that the opposite is true when using the Small Magellanic Cloud dust extinction curve. This demonstrates the strong dependence of UV colours on dust properties and highlights the inadequacy of using the UV continuum slope as a tracer of dust attenuation without any further knowledge of the galaxy inclination or dust characteristics in high-redshift galaxies.


Gonzalez-Perez, V., Lacey, C., Baugh, C., Frenk, C., & Wilkins, S. (2013). The ultraviolet colours and dust attenuation of Lyman-break galaxies. Monthly Notices of the Royal Astronomical Society, 429(2), 1609-1625.

Journal Article Type Article
Publication Date Feb 1, 2013
Deposit Date Mar 27, 2013
Publicly Available Date Jun 27, 2014
Journal Monthly Notices of the Royal Astronomical Society
Print ISSN 0035-8711
Electronic ISSN 1365-2966
Publisher Royal Astronomical Society
Peer Reviewed Peer Reviewed
Volume 429
Issue 2
Pages 1609-1625
Keywords Galaxies: evolution, Galaxies: formation, Galaxies: high-redshift.


Published Journal Article (1.1 Mb)

Copyright Statement
This article has been accepted for publication in Monthly notices of the Royal Astronomical Society © 2013 The Authors Published by Oxford University Press on behalf of Royal Astronomical Society. All rights reserved.

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