The fraction of dark matter within galaxies from the IllustrisTNG simulations

We use the IllustrisTNG (TNG) cosmological simulations to provide theoretical expectations for the dark matter mass fractions (DMFs) and circular velocity profiles of galaxies. TNG predicts flat circular velocity curves for z = 0 Milky Way (MW)-like galaxies beyond a few kpc from the galaxy centre,...

Full description

Bibliographic Details
Main Authors: Lovell, Mark R., Pillepich, Annalisa, Genel, Shy, Nelson, Dylan, Springel, Volker, Pakmor, Ru ̈diger, Marinacci, Federico, Torrey, Paul, Vogelsberger, Mark, Alabi, Adebusola, Hernquist, Lars
Other Authors: Massachusetts Institute of Technology. Department of Physics
Format: Article
Language:English
Published: Oxford University Press (OUP) 2019
Online Access:https://hdl.handle.net/1721.1/121226
_version_ 1826202412381110272
author Lovell, Mark R.
Pillepich, Annalisa
Genel, Shy
Nelson, Dylan
Springel, Volker
Pakmor, Ru ̈diger
Marinacci, Federico
Torrey, Paul
Vogelsberger, Mark
Alabi, Adebusola
Hernquist, Lars
author2 Massachusetts Institute of Technology. Department of Physics
author_facet Massachusetts Institute of Technology. Department of Physics
Lovell, Mark R.
Pillepich, Annalisa
Genel, Shy
Nelson, Dylan
Springel, Volker
Pakmor, Ru ̈diger
Marinacci, Federico
Torrey, Paul
Vogelsberger, Mark
Alabi, Adebusola
Hernquist, Lars
author_sort Lovell, Mark R.
collection MIT
description We use the IllustrisTNG (TNG) cosmological simulations to provide theoretical expectations for the dark matter mass fractions (DMFs) and circular velocity profiles of galaxies. TNG predicts flat circular velocity curves for z = 0 Milky Way (MW)-like galaxies beyond a few kpc from the galaxy centre, in better agreement with observational constraints than its predecessor, Illustris. TNG also predicts an enhancement of the dark matter mass within the 3D stellar half-mass radius (r half ; M 200c = 10¹⁰-10¹³ M[subscript ⊙], z ≤ 2) compared to its dark matter only and Illustris counterparts. This enhancement leads TNG present-day galaxies to be dominated by dark matter within their inner regions, with f DM (< r half ) ≳ 0.5 at all masses and with a minimum for MW-mass galaxies. The 1σ scatter is ≲10 per cent at all apertures, which is smaller than that inferred by some observational data sets, e.g. 40 per cent from the SLUGGS survey. TNG agrees with the majority of the observationally inferred values for elliptical galaxies once a consistent initial mass function is adopted (Chabrier) and the DMFs are measured within the same apertures. The DMFs measured within rhalf increase towards lower redshifts: this evolution is dominated by the increase in galaxy size with time. At z ~ 2, the DMF in disc-like TNG galaxies decreases with increasing galaxy mass, with f[subscript DM] (< r[subscript half ]) ~ 0.10-0.65 for 10 ¹⁰ ≲ M[subscript stars] /M[subscript ⊙] ≲ 10 ¹² , and are two times higher than if TNG galaxies resided in Navarro-Frenk-White dark matter haloes unaffected by baryonic physics. It remains to be properly assessed whether recent observational estimates of the DMFs at z ~2 rule out the contraction of the dark matter haloes predicted by the TNG model.
first_indexed 2024-09-23T12:07:03Z
format Article
id mit-1721.1/121226
institution Massachusetts Institute of Technology
language English
last_indexed 2024-09-23T12:07:03Z
publishDate 2019
publisher Oxford University Press (OUP)
record_format dspace
spelling mit-1721.1/1212262022-10-01T08:18:11Z The fraction of dark matter within galaxies from the IllustrisTNG simulations Lovell, Mark R. Pillepich, Annalisa Genel, Shy Nelson, Dylan Springel, Volker Pakmor, Ru ̈diger Marinacci, Federico Torrey, Paul Vogelsberger, Mark Alabi, Adebusola Hernquist, Lars Massachusetts Institute of Technology. Department of Physics MIT Kavli Institute for Astrophysics and Space Research We use the IllustrisTNG (TNG) cosmological simulations to provide theoretical expectations for the dark matter mass fractions (DMFs) and circular velocity profiles of galaxies. TNG predicts flat circular velocity curves for z = 0 Milky Way (MW)-like galaxies beyond a few kpc from the galaxy centre, in better agreement with observational constraints than its predecessor, Illustris. TNG also predicts an enhancement of the dark matter mass within the 3D stellar half-mass radius (r half ; M 200c = 10¹⁰-10¹³ M[subscript ⊙], z ≤ 2) compared to its dark matter only and Illustris counterparts. This enhancement leads TNG present-day galaxies to be dominated by dark matter within their inner regions, with f DM (< r half ) ≳ 0.5 at all masses and with a minimum for MW-mass galaxies. The 1σ scatter is ≲10 per cent at all apertures, which is smaller than that inferred by some observational data sets, e.g. 40 per cent from the SLUGGS survey. TNG agrees with the majority of the observationally inferred values for elliptical galaxies once a consistent initial mass function is adopted (Chabrier) and the DMFs are measured within the same apertures. The DMFs measured within rhalf increase towards lower redshifts: this evolution is dominated by the increase in galaxy size with time. At z ~ 2, the DMF in disc-like TNG galaxies decreases with increasing galaxy mass, with f[subscript DM] (< r[subscript half ]) ~ 0.10-0.65 for 10 ¹⁰ ≲ M[subscript stars] /M[subscript ⊙] ≲ 10 ¹² , and are two times higher than if TNG galaxies resided in Navarro-Frenk-White dark matter haloes unaffected by baryonic physics. It remains to be properly assessed whether recent observational estimates of the DMFs at z ~2 rule out the contraction of the dark matter haloes predicted by the TNG model. 2019-06-07T20:42:19Z 2019-06-07T20:42:19Z 2018-08 2018-08 2019-06-07T19:07:15Z Article http://purl.org/eprint/type/JournalArticle 0035-8711 1365-2966 https://hdl.handle.net/1721.1/121226 Lovell, Mark R. et al. "The fraction of dark matter within galaxies from the IllustrisTNG simulations." Monthly Notices of the Royal Astronomical Society 481, 2 (August 2018): 1950–1975 © 2018 The Author(s) en http://dx.doi.org/10.1093/MNRAS/STY2339 Monthly Notices of the Royal Astronomical Society Creative Commons Attribution-Noncommercial-Share Alike http://creativecommons.org/licenses/by-nc-sa/4.0/ application/pdf Oxford University Press (OUP) arXiv
spellingShingle Lovell, Mark R.
Pillepich, Annalisa
Genel, Shy
Nelson, Dylan
Springel, Volker
Pakmor, Ru ̈diger
Marinacci, Federico
Torrey, Paul
Vogelsberger, Mark
Alabi, Adebusola
Hernquist, Lars
The fraction of dark matter within galaxies from the IllustrisTNG simulations
title The fraction of dark matter within galaxies from the IllustrisTNG simulations
title_full The fraction of dark matter within galaxies from the IllustrisTNG simulations
title_fullStr The fraction of dark matter within galaxies from the IllustrisTNG simulations
title_full_unstemmed The fraction of dark matter within galaxies from the IllustrisTNG simulations
title_short The fraction of dark matter within galaxies from the IllustrisTNG simulations
title_sort fraction of dark matter within galaxies from the illustristng simulations
url https://hdl.handle.net/1721.1/121226
work_keys_str_mv AT lovellmarkr thefractionofdarkmatterwithingalaxiesfromtheillustristngsimulations
AT pillepichannalisa thefractionofdarkmatterwithingalaxiesfromtheillustristngsimulations
AT genelshy thefractionofdarkmatterwithingalaxiesfromtheillustristngsimulations
AT nelsondylan thefractionofdarkmatterwithingalaxiesfromtheillustristngsimulations
AT springelvolker thefractionofdarkmatterwithingalaxiesfromtheillustristngsimulations
AT pakmorrudiger thefractionofdarkmatterwithingalaxiesfromtheillustristngsimulations
AT marinaccifederico thefractionofdarkmatterwithingalaxiesfromtheillustristngsimulations
AT torreypaul thefractionofdarkmatterwithingalaxiesfromtheillustristngsimulations
AT vogelsbergermark thefractionofdarkmatterwithingalaxiesfromtheillustristngsimulations
AT alabiadebusola thefractionofdarkmatterwithingalaxiesfromtheillustristngsimulations
AT hernquistlars thefractionofdarkmatterwithingalaxiesfromtheillustristngsimulations
AT lovellmarkr fractionofdarkmatterwithingalaxiesfromtheillustristngsimulations
AT pillepichannalisa fractionofdarkmatterwithingalaxiesfromtheillustristngsimulations
AT genelshy fractionofdarkmatterwithingalaxiesfromtheillustristngsimulations
AT nelsondylan fractionofdarkmatterwithingalaxiesfromtheillustristngsimulations
AT springelvolker fractionofdarkmatterwithingalaxiesfromtheillustristngsimulations
AT pakmorrudiger fractionofdarkmatterwithingalaxiesfromtheillustristngsimulations
AT marinaccifederico fractionofdarkmatterwithingalaxiesfromtheillustristngsimulations
AT torreypaul fractionofdarkmatterwithingalaxiesfromtheillustristngsimulations
AT vogelsbergermark fractionofdarkmatterwithingalaxiesfromtheillustristngsimulations
AT alabiadebusola fractionofdarkmatterwithingalaxiesfromtheillustristngsimulations
AT hernquistlars fractionofdarkmatterwithingalaxiesfromtheillustristngsimulations