TY - JOUR
T1 - The Local Group on FIRE
T2 - Dwarf galaxy populations across a suite of hydrodynamic simulations
AU - Garrison-Kimmel, Shea
AU - Hopkins, Philip F.
AU - Wetzel, Andrew
AU - Bullock, James S.
AU - Boylan-Kolchin, Michael
AU - Kereš, Dušan
AU - Faucher-Giguère, Claude André
AU - El-Badry, Kareem
AU - Lamberts, Astrid
AU - Quataert, Eliot
AU - Sanderson, Robyn
N1 - Publisher Copyright:
© 2019 The Author(s).
PY - 2019/7/1
Y1 - 2019/7/1
N2 - We present a new set of high-resolution hydrodynamic cosmological zoom-in simulations that apply the Feedback In Realistic Environments physics to both Local Group (LG)-like and isolated MilkyWay (MW)-like volumes (10 host systems in total with a baryonic particle mass ≃3500-7000M⊙).We study the stellar mass functions, circular velocity or mass profiles, and velocity dispersions of the dwarf galaxy populations. The simulations reproduce the stellar mass function and central densities ofMWsatellite dwarfs forM∗≥105.5M⊙ and predict the existence of ∼3 unidentified galaxies with M∗∼ 105M⊙ within 300 kpc of the MW. Overall, we find no evidence for the classical missing satellites or too-big-to-fail (TBTF) problems for satellite galaxies in our sample. Among the satellites, TBTF is resolved primarily by subhalo disruption and overall mass-loss; central density profiles of subhaloes are of secondary importance. For non-satellite galaxies, our LG-like simulations predict as many as ∼10 as-ofyet unseen galaxies at distances 0.3-1Mpc from both hosts, with M∗≃ 105-6M⊙ (in haloes with Vmax ∼ 20 km s-1), albeit with large halo-to-halo variance. None of our simulations produces a compact, baryon-dominated, high-density dwarf elliptical-type galaxy (with Vcirc ≳ 35 km s-1 at r < 1 kpc), of which six may appear in the LG (but none in the MW). It may therefore remain a challenge to reproduce the full diversity of the dwarf population, including both the highest and lowest density systems.
AB - We present a new set of high-resolution hydrodynamic cosmological zoom-in simulations that apply the Feedback In Realistic Environments physics to both Local Group (LG)-like and isolated MilkyWay (MW)-like volumes (10 host systems in total with a baryonic particle mass ≃3500-7000M⊙).We study the stellar mass functions, circular velocity or mass profiles, and velocity dispersions of the dwarf galaxy populations. The simulations reproduce the stellar mass function and central densities ofMWsatellite dwarfs forM∗≥105.5M⊙ and predict the existence of ∼3 unidentified galaxies with M∗∼ 105M⊙ within 300 kpc of the MW. Overall, we find no evidence for the classical missing satellites or too-big-to-fail (TBTF) problems for satellite galaxies in our sample. Among the satellites, TBTF is resolved primarily by subhalo disruption and overall mass-loss; central density profiles of subhaloes are of secondary importance. For non-satellite galaxies, our LG-like simulations predict as many as ∼10 as-ofyet unseen galaxies at distances 0.3-1Mpc from both hosts, with M∗≃ 105-6M⊙ (in haloes with Vmax ∼ 20 km s-1), albeit with large halo-to-halo variance. None of our simulations produces a compact, baryon-dominated, high-density dwarf elliptical-type galaxy (with Vcirc ≳ 35 km s-1 at r < 1 kpc), of which six may appear in the LG (but none in the MW). It may therefore remain a challenge to reproduce the full diversity of the dwarf population, including both the highest and lowest density systems.
KW - Cosmology: Theory
KW - Galaxies: Dwarf
KW - Galaxies: Formation
KW - Galaxies: Local Group
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U2 - 10.1093/mnras/stz1317
DO - 10.1093/mnras/stz1317
M3 - Article
AN - SCOPUS:85069517505
SN - 0035-8711
VL - 487
SP - 1380
EP - 1399
JO - Monthly Notices of the Royal Astronomical Society
JF - Monthly Notices of the Royal Astronomical Society
IS - 1
ER -