UCL Discovery
UCL home » Library Services » Electronic resources » UCL Discovery

Comparing semi-analytic particle tagging and hydrodynamical simulations of the Milky Way's stellar halo

Cooper, AP; Cole, S; Frenk, CS; Le Bret, T; Pontzen, A; (2017) Comparing semi-analytic particle tagging and hydrodynamical simulations of the Milky Way's stellar halo. Monthly Notices of the Royal Astronomical Society , 469 (2) pp. 1691-1712. 10.1093/mnras/stx955. Green open access

[thumbnail of Pontzen_stx955.pdf]
Preview
Text
Pontzen_stx955.pdf - Published Version

Download (4MB) | Preview

Abstract

Particle tagging is an efficient, but approximate, technique for using cosmological N-body simulations to model the phase-space evolution of the stellar populations predicted, for example, by a semi-analytic model of galaxy formation. We test the technique developed by Cooper et al. (which we call STINGS here) by comparing particle tags with stars in a smooth particle hydrodynamic (SPH) simulation. We focus on the spherically averaged density profile of stars accreted from satellite galaxies in a Milky Way (MW)-like system. The stellar profile in the SPH simulation can be recovered accurately by tagging dark matter (DM) particles in the same simulation according to a prescription based on the rank order of particle binding energy. Applying the same prescription to an N-body version of this simulation produces a density profile differing from that of the SPH simulation by ≲10 per cent on average between 1 and 200 kpc. This confirms that particle tagging can provide a faithful and robust approximation to a self-consistent hydrodynamical simulation in this regime (in contradiction to previous claims in the literature). We find only one systematic effect, likely due to the collisionless approximation, namely that massive satellites in the SPH simulation are disrupted somewhat earlier than their collisionless counterparts. In most cases, this makes remarkably little difference to the spherically averaged distribution of their stellar debris. We conclude that, for galaxy formation models that do not predict strong baryonic effects on the present-day DM distribution of MW-like galaxies or their satellites, differences in stellar halo predictions associated with the treatment of star formation and feedback are much more important than those associated with the dynamical limitations of collisionless particle tagging.

Type: Article
Title: Comparing semi-analytic particle tagging and hydrodynamical simulations of the Milky Way's stellar halo
Open access status: An open access version is available from UCL Discovery
DOI: 10.1093/mnras/stx955
Publisher version: http://doi.org/10.1093/mnras/stx955
Language: English
Additional information: © 2017 The Authors. Published by Oxford University Press on behalf of the Royal Astronomical Society. This version is the version of record. For information on re-use, please refer to the publisher’s terms and conditions.
Keywords: Science & Technology, Physical Sciences, Astronomy & Astrophysics, methods: numerical, galaxies: dwarf, galaxies: haloes, galaxies: structure, DWARF SPHEROIDAL GALAXIES, DARK-MATTER HALOES, SPIRAL GALAXIES, LOCAL GROUP, LAMBDA-CDM, EVOLUTION, STARS, MODEL, MASS, SUBSTRUCTURE
UCL classification: UCL
UCL > Provost and Vice Provost Offices > UCL BEAMS
UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences
UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences > Dept of Physics and Astronomy
URI: https://discovery.ucl.ac.uk/id/eprint/1546881
Downloads since deposit
60Downloads
Download activity - last month
Download activity - last 12 months
Downloads by country - last 12 months

Archive Staff Only

View Item View Item