Skip to main content

Research Repository

Advanced Search

Ring galaxies in the EAGLE hydrodynamical simulations

Elagali, Ahmed; Lagos, Claudia D.P.; Wong, O. Ivy; Staveley-Smith, Lister; Trayford, James W.; Schaller, Matthieu; Yuan, Tiantian; Abadi, Mario G.

Ring galaxies in the EAGLE hydrodynamical simulations Thumbnail


Ahmed Elagali

Claudia D.P. Lagos

O. Ivy Wong

Lister Staveley-Smith

James W. Trayford

Tiantian Yuan

Mario G. Abadi


We study the formation and evolution of ring galaxies in the Evolution and Assembly of GaLaxies and their Environments (EAGLE) simulations. We use the largest reference model Ref-L100N1504, a cubic cosmological volume of 100 cMpc on a side, to identify and characterize these systems through cosmic time. The number density of ring galaxies in EAGLE is in broad agreement with the observations. The vast majority of ring galaxies identified in EAGLE (83 per cent) have an interaction origin, i.e. form when one or more companion galaxies drop-through a disc galaxy. The remainder (17 per cent) have very long-lived ring morphologies (>2 Gyr) and host strong bars. Ring galaxies are HI-rich galaxies, yet display inefficient star formation activity and tend to reside in the green valley particularly at z 0.5. This inefficiency is mainly due to the low pressure and metallicity of their interstellar medium (ISM) compared with the ISM of similar star-forming galaxies. We find that the interaction(s) is responsible for decreasing the ISM pressure by causing the ISM gas to flow from the inner regions to the outer disc, where the ring feature forms. At a fixed radius, the star formation efficiency of ring galaxies is indistinguishable from their star-forming counterparts, and thus the main reason for their integrated lower efficiency is the different gas surface density profiles. Since galaxy morphologies are not used to tune the parameters in hydrodynamical simulations, the experiment performed here demonstrates the success of the current numerical models in EAGLE.


Elagali, A., Lagos, C. D., Wong, O. I., Staveley-Smith, L., Trayford, J. W., Schaller, M., …Abadi, M. G. (2018). Ring galaxies in the EAGLE hydrodynamical simulations. Monthly Notices of the Royal Astronomical Society, 481(3), 2951-2969.

Journal Article Type Article
Acceptance Date Sep 5, 2018
Online Publication Date Sep 10, 2018
Publication Date Sep 10, 2018
Deposit Date Oct 18, 2018
Publicly Available Date Oct 19, 2018
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 481
Issue 3
Pages 2951-2969


Published Journal Article (12.8 Mb)

Copyright Statement
This article has been accepted for publication in Monthly Notices of the Royal Astronomical Society © 2018 The Authors. Published by Oxford University Press on behalf of the Royal Astronomical Society. All rights reserved.

You might also like

Downloadable Citations