The ARTEMIS simulations: stellar haloes of Milky Way-mass galaxies

Font, A.S.; McCarthy, I.G.; Poole-Mckenzie, R.; Stafford, S.G.; Brown, S.T.; Schaye, J.; Crain, R.A.; Theuns, T.

doi:10.1093/mnras/staa2463

The ARTEMIS simulations: stellar haloes of Milky Way-mass galaxies Thumbnail

Authors

A.S. Font

I.G. McCarthy

R. Poole-Mckenzie

S.G. Stafford

Mr Shaun Brown shaun.t.brown@durham.ac.uk
Post Doctoral Research Associate

J. Schaye

R.A. Crain

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

Abstract

We introduce the Assembly of high-ResoluTion Eagle-simulations of MIlky Way-type galaxieS (ARTEMIS) simulations, a new set of 42 zoomed-in, high-resolution (baryon particle mass of ≈2×104M⊙h−1⁠), hydrodynamical simulations of galaxies residing in haloes of Milky Way mass, simulated with the EAGLE galaxy formation code with re-calibrated stellar feedback. In this study, we analyse the structure of stellar haloes, specifically the mass density, surface brightness, metallicity, colour, and age radial profiles, finding generally very good agreement with recent observations of local galaxies. The stellar density profiles are well fitted by broken power laws, with inner slopes of ≈−3, outer slopes of ≈−4, and break radii that are typically ≈20–40 kpc. The break radii generally mark the transition between in situ formation and accretion-driven formation of the halo. The metallicity, colour, and age profiles show mild large-scale gradients, particularly when spherically averaged or viewed along the major axes. Along the minor axes, however, the profiles are nearly flat, in agreement with observations. Overall, the structural properties can be understood by two factors: that in situ stars dominate the inner regions and that they reside in a spatially flattened distribution that is aligned with the disc. Observations targeting both the major and minor axes of galaxies are thus required to obtain a complete picture of stellar haloes.

Citation

Font, A., McCarthy, I., Poole-Mckenzie, R., Stafford, S., Brown, S., Schaye, J., …Theuns, T. (2020). The ARTEMIS simulations: stellar haloes of Milky Way-mass galaxies. Monthly Notices of the Royal Astronomical Society, 498(2), 1765-1785. https://doi.org/10.1093/mnras/staa2463

Journal Article Type	Article
Acceptance Date	Aug 12, 2020
Online Publication Date	Aug 17, 2020
Publication Date	2020-10
Deposit Date	Oct 20, 2020
Publicly Available Date	Oct 22, 2020
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	498
Issue	2
Pages	1765-1785
DOI	https://doi.org/10.1093/mnras/staa2463

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Copyright Statement
This article has been accepted for publication in Monthly notices of the Royal Astronomical Society. ©: 2020 The Author(s). Published by Oxford University Press on behalf of the Royal Astronomical Society. All rights reserved.