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Colours and luminosities of z = 0.1 galaxies in the EAGLE simulation

Trayford, J.W.; Theuns, T.; Bower, R.G.; Schaye, J.; Furlong, M.; Schaller, M.; Frenk, C.S.; Crain, R.A.; Dalla Vecchia, C.; McCarthy, I.G.

Colours and luminosities of z = 0.1 galaxies in the EAGLE simulation Thumbnail


J.W. Trayford

R.G. Bower

J. Schaye

M. Furlong

M. Schaller

R.A. Crain

C. Dalla Vecchia

I.G. McCarthy


We calculate the colours and luminosities of redshift z = 0.1 galaxies from the eagle simulation suite using the galaxev population synthesis models. We take into account obscuration by dust in birth clouds and diffuse interstellar medium using a two-component screen model, following the prescription of Charlot and Fall. We compare models in which the dust optical depth is constant to models where it depends on gas metallicity, gas fraction and orientation. The colours of eagle galaxies for the more sophisticated models are in broad agreement with those of observed galaxies. In particular, eagle produces a red sequence of passive galaxies and a blue cloud of star-forming galaxies, with approximately the correct fraction of galaxies in each population and with g − r colours within 0.1 mag of those observed. Luminosity functions from ultraviolet to near-infrared wavelengths differ from observations at a level comparable to systematic shifts resulting from a choice between Petrosian and Kron photometric apertures. Despite the generally good agreement there are clear discrepancies with observations. The blue cloud of eagle galaxies extends to somewhat higher luminosities than in the data, consistent with the modest underestimate of the passive fraction in massive eagle galaxies. There is also a moderate excess of bright blue galaxies compared to observations. The overall level of agreement with the observed colour distribution suggests that eagle galaxies at z = 0.1 have ages, metallicities and levels of obscuration that are comparable to those of observed galaxies.


Trayford, J., Theuns, T., Bower, R., Schaye, J., Furlong, M., Schaller, M., …McCarthy, I. (2015). Colours and luminosities of z = 0.1 galaxies in the EAGLE simulation. Monthly Notices of the Royal Astronomical Society, 452(3), 2879-2896.

Journal Article Type Article
Acceptance Date Jun 30, 2015
Online Publication Date Jul 29, 2015
Publication Date Sep 21, 2015
Deposit Date Feb 10, 2016
Publicly Available Date Feb 18, 2016
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 452
Issue 3
Pages 2879-2896
Keywords Galaxies: general, Galaxies: luminosity function, mass function.


Published Journal Article (2.1 Mb)

Copyright Statement
This article has been accepted for publication in Monthly notices of the Royal Astronomical Society ©: 2015 The Authors Published by Oxford University Press on behalf of the Royal Astronomical Society. All rights reserved.

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