TY - JOUR
T1 - NIHAo XV
T2 - The environmental impact of the host galaxy on galactic satellite and field dwarf galaxies
AU - Buck, Tobias
AU - Macciò, Andrea V.
AU - Dutton, Aaron A.
AU - Obreja, Aura
AU - Frings, Jonas
N1 - Funding Information:
We would like to thank Hans-Walter Rix for fruitful discussions and very helpful comments on this work. TB would like to thank Marcel Pawlowski, Anna Bonaca, and Nicolas Martin for helpful comments and suggestions on this work. This research made use of the PYN-BODY package Pontzen et al. (2013) to analyse the simulations and used the PYTHON package MATPLOTLIB (Hunter 2007) to display all the figures in this work. Data analysis for this work made intensive use of the PYTHON library SCIPY (Jones et al. 2001), in particular NUMPY AND IPYTHON (Pérez & Granger 2007; Walt, Colbert & Varoquaux 2011). TB acknowledges support from the Sonder-forschungsbereich SFB 881 ‘The Milky Way System’ (sub-project A2) of the German Research Foundation (DFG). AO is funded by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) – MO 2979/1-1. The authors gratefully acknowledge the Gauss Centre for Supercomputing e.V. (www.gauss-centre.eu) for funding this project by providing computing time on the GCS Supercomputer SuperMUC at the Leibniz Supercomputing Centre (http://www.lrz.de). This research was carried out on the High Performance Computing resources at New York University Abu Dhabi; simulations have been performed on the ISAAC cluster of the Max-Planck-Institut für Astronomie at the Rechenzentrum in Garching and the HYDRA and DRACO clusters at the Rechen-zentrum in Garching. We greatly appreciate the contributions of all these computing allocations.
Funding Information:
We would like to thank Hans-Walter Rix for fruitful discussions and very helpful comments on this work. TB would like to thank Marcel Pawlowski, Anna Bonaca, and Nicolas Martin for helpful comments and suggestions on this work. This research made use of the PYN-BODY package Pontzen et al. (2013) to analyse the simulations and used the PYTHON package MATPLOTLIB (Hunter 2007) to display all the figures in this work. Data analysis for this work made intensive use of the PYTHON library SCIPY (Jones et al. 2001), in particular NUMPY AND IPYTHON (Pérez & Granger 2007; Walt, Colbert & Varoquaux 2011). TB acknowledges support from the Sonder-forschungsbereich SFB 881 'The Milky Way System' (sub-project A2) of the German Research Foundation (DFG). AO is funded by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) - MO 2979/1-1. The authors gratefully acknowledge the Gauss Centre for Supercomputing e.V. (www.gauss-centre.eu) for funding this project by providing computing time on the GCS Supercomputer SuperMUC at the Leibniz Supercomputing Centre (http://www.lrz.de). This research was carried out on the High Performance Computing resources at New York University Abu Dhabi; simulations have been performed on the ISAAC cluster of the Max-Planck-Institut für Astronomie at the Rechenzentrum in Garching and the HYDRA and DRACO clusters at the Rechenzentrum in Garching. We greatly appreciate the contributions of all these computing allocations.
Publisher Copyright:
© 2018 The Author(s)
PY - 2019/2/11
Y1 - 2019/2/11
N2 - We study the impact of the host on dwarf galaxy properties using four new Milky Way (MW)like, ultra-high-resolution simulations (Npart > 107) from the NIHAO project. We split our sample into satellite (R < R200), nearby (1 < R/R200 < 2.5), and field (R > 2.5R200) galaxies. Simulated galaxies from all three groups are in excellent agreement with Local Group dwarf galaxies in terms of the stellar mass-velocity dispersion and stellar mass-metallicity relations, star formation histories, and stellar mass functions. Satellites and nearby galaxies show lower velocity dispersions and gas fractions compared to field galaxies. While field galaxies follow global abundance matching relations, satellites and nearby galaxies deviate from them, showing lower dark matter masses for a given stellar mass. The reason for this deficit in dark matter mass is the substantial mass loss experienced by satellites and ∼80 per cent of the nearby galaxies while orbiting inside R200 at earlier times. However, both satellites and nearby objects fall back on to the relation for field galaxies if we use the maximum of their virial mass instead of the present-day value. This allows us to provide estimates for the peak masses of observed Local Group galaxies. Finally, using radial velocities, distances, and the velocity dispersion-stellar mass relation from our simulations, we derive a metric to distinguish between galaxies harassed by the central object and unaffected ones. Applying this metric to observed objects, we find that even far-away dwarf galaxies like Eri II (D ≈ 370 kpc) have a strong probability (≈83 per cent) of having been affected by the MW in the past. This naturally explains the lack of gas and recent star formation seen in Eri II.
AB - We study the impact of the host on dwarf galaxy properties using four new Milky Way (MW)like, ultra-high-resolution simulations (Npart > 107) from the NIHAO project. We split our sample into satellite (R < R200), nearby (1 < R/R200 < 2.5), and field (R > 2.5R200) galaxies. Simulated galaxies from all three groups are in excellent agreement with Local Group dwarf galaxies in terms of the stellar mass-velocity dispersion and stellar mass-metallicity relations, star formation histories, and stellar mass functions. Satellites and nearby galaxies show lower velocity dispersions and gas fractions compared to field galaxies. While field galaxies follow global abundance matching relations, satellites and nearby galaxies deviate from them, showing lower dark matter masses for a given stellar mass. The reason for this deficit in dark matter mass is the substantial mass loss experienced by satellites and ∼80 per cent of the nearby galaxies while orbiting inside R200 at earlier times. However, both satellites and nearby objects fall back on to the relation for field galaxies if we use the maximum of their virial mass instead of the present-day value. This allows us to provide estimates for the peak masses of observed Local Group galaxies. Finally, using radial velocities, distances, and the velocity dispersion-stellar mass relation from our simulations, we derive a metric to distinguish between galaxies harassed by the central object and unaffected ones. Applying this metric to observed objects, we find that even far-away dwarf galaxies like Eri II (D ≈ 370 kpc) have a strong probability (≈83 per cent) of having been affected by the MW in the past. This naturally explains the lack of gas and recent star formation seen in Eri II.
KW - Dark matter
KW - Galaxies: kinematics and dynamics
KW - Galaxy: formation
KW - Local Group
KW - Methods: numerical
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U2 - 10.1093/mnras/sty2913
DO - 10.1093/mnras/sty2913
M3 - Article
AN - SCOPUS:85067002391
SN - 0035-8711
VL - 483
SP - 1314
EP - 1341
JO - Monthly Notices of the Royal Astronomical Society
JF - Monthly Notices of the Royal Astronomical Society
IS - 1
ER -