Galaxies in the EAGLE hydrodynamical simulation and in the Durham and Munich semi-analytical models

Guo, Q.; Gonzalez-Perez, V.; Guo, Q.; Schaller, M.; Furlong, M.; Bower, R.G.; Cole, S.; Crain, R.A.; Frenk, C.S.; Helly, J.C.; Lacey, C.G.; Lagos, C. d. P.; Mitchell, P.; Schaye, J.; Theuns, T.

doi:10.1093/mnras/stw1525

Galaxies in the EAGLE hydrodynamical simulation and in the Durham and Munich semi-analytical models

Guo, Q.; Gonzalez-Perez, V.; Guo, Q.; Schaller, M.; Furlong, M.; Bower, R.G.; Cole, S.; Crain, R.A.; Frenk, C.S.; Helly, J.C.; Lacey, C.G.; Lagos, C. d. P.; Mitchell, P.; Schaye, J.; Theuns, T.

Authors

Q. Guo

V. Gonzalez-Perez

Q. Guo

M. Schaller

M. Furlong

R.G. Bower

Professor Shaun Cole shaun.cole@durham.ac.uk
Director of the Institute for Computational Cosmology

R.A. Crain

Professor Carlos Frenk c.s.frenk@durham.ac.uk
Professor

Dr John Helly j.c.helly@durham.ac.uk
Chief Experimental Officer

Professor Cedric Lacey cedric.lacey@durham.ac.uk
Professor

C. d. P. Lagos

P. Mitchell

J. Schaye

Professor Tom Theuns tom.theuns@durham.ac.uk
Professor

Abstract

We compare global predictions from the EAGLE hydrodynamical simulation, and two semi-analytic (SA) models of galaxy formation, L-GALAXIES and GALFORM. All three models include the key physical processes for the formation and evolution of galaxies and their parameters are calibrated against a small number of observables at z ≈ 0. The two SA models have been applied to merger trees constructed from the EAGLE dark matter only simulation. We find that at z ≤ 2, both the galaxy stellar mass functions for stellar masses M* < 1010.5 M⊙ and the median specific star formation rates (sSFRs) in the three models agree to better than 0.4 dex. The evolution of the sSFR predicted by the three models closely follows the mass assembly history of dark matter haloes. In both EAGLE and L-GALAXIES there are more central passive galaxies with M* < 109.5 M⊙ than in GALFORM. This difference is related to galaxies that have entered and then left a larger halo and which are treated as satellites in GALFORM. In the range 0 < z < 1, the slope of the evolution of the star formation rate density in EAGLE is a factor of ≈1.5 steeper than for the two SA models. The median sizes for galaxies with M* > 109.5 M⊙ differ in some instances by an order of magnitude, while the stellar mass–size relation in EAGLE is a factor of ≈2 tighter than for the two SA models. Our results suggest the need for a revision of how SA models treat the effect of baryonic self-gravity on the underlying dark matter. The treatment of gas flows in the models needs to be revised based on detailed comparison with observations to understand in particular the evolution of the stellar mass–metallicity relation.

Citation

Guo, Q., Gonzalez-Perez, V., Guo, Q., Schaller, M., Furlong, M., Bower, R., …Theuns, T. (2016). Galaxies in the EAGLE hydrodynamical simulation and in the Durham and Munich semi-analytical models. Monthly Notices of the Royal Astronomical Society, 461(4), 3457-3482. https://doi.org/10.1093/mnras/stw1525

Journal Article Type	Article
Acceptance Date	Jun 22, 2016
Online Publication Date	Jun 24, 2016
Publication Date	Oct 1, 2016
Deposit Date	Sep 28, 2016
Publicly Available Date	Oct 6, 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	461
Issue	4
Pages	3457-3482
DOI	https://doi.org/10.1093/mnras/stw1525
Related Public URLs	https://arxiv.org/abs/1512.00015

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This article has been published in Monthly Notices of the Royal Astronomical Society ©: 2016 The Authors Published by Oxford University Press on behalf of the Royal Astronomical Society. All rights reserved.