Skip to main content

Research Repository

Advanced Search

Optical colours and spectral indices of z = 0.1 eagle galaxies with the 3D dust radiative transfer code skirt

Trayford, J.W.; Camps, P.; Theuns, T.; Baes, M.; Bower, R.G.; Crain, R.A.; Gunawardhana, M.L.P.; Schaller, M.; Schaye, J.; Frenk, C.S.

Optical colours and spectral indices of z = 0.1 eagle galaxies with the 3D dust radiative transfer code skirt Thumbnail


Authors

J.W. Trayford

P. Camps

M. Baes

R.G. Bower

R.A. Crain

M.L.P. Gunawardhana

M. Schaller

J. Schaye



Abstract

We present mock optical images, broad-band and H α fluxes, and D4000 spectral indices for 30 145 galaxies from the EAGLE hydrodynamical simulation at redshift z = 0.1, modelling dust with the SKIRT Monte Carlo radiative transfer code. The modelling includes a subgrid prescription for dusty star-forming regions, with both the subgrid obscuration of these regions and the fraction of metals in diffuse interstellar dust calibrated against far-infrared fluxes of local galaxies. The predicted optical colours as a function of stellar mass agree well with observation, with the SKIRT model showing marked improvement over a simple dust-screen model. The orientation dependence of attenuation is weaker than observed because EAGLE galaxies are generally puffier than real galaxies, due to the pressure floor imposed on the interstellar medium (ISM). The mock H α luminosity function agrees reasonably well with the data, and we quantify the extent to which dust obscuration affects observed H α fluxes. The distribution of D4000 break values is bimodal, as observed. In the simulation, 20 per cent of galaxies deemed ‘passive' for the SKIRT model, i.e. exhibiting D4000 >1.8, are classified ‘active' when ISM dust attenuation is not included. The fraction of galaxies with stellar mass greater than 1010 M⊙ that are deemed passive is slightly smaller than observed, which is due to low levels of residual star formation in these simulated galaxies. Colour images, fluxes and spectra of EAGLE galaxies are to be made available through the public EAGLE data base.

Citation

Trayford, J., Camps, P., Theuns, T., Baes, M., Bower, R., Crain, R., …Frenk, C. (2017). Optical colours and spectral indices of z = 0.1 eagle galaxies with the 3D dust radiative transfer code skirt. Monthly Notices of the Royal Astronomical Society, 470(1), 771-799. https://doi.org/10.1093/mnras/stx1051

Journal Article Type Article
Acceptance Date Apr 28, 2017
Online Publication Date May 9, 2017
Publication Date Sep 1, 2017
Deposit Date Jul 18, 2017
Publicly Available Date Jul 18, 2017
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 470
Issue 1
Pages 771-799
DOI https://doi.org/10.1093/mnras/stx1051

Files

Published Journal Article (5 Mb)
PDF

Copyright Statement
This article has been accepted for publication in Monthly Notices of the Royal Astronomical Society © 2017. The Authors. Published by Oxford University Press on behalf of the Royal Astronomical Society.







You might also like



Downloadable Citations