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VINTERGATAN-GM : How do mergers affect the satellite populations of MW-like galaxies?

Joshi, Gandhali D. ; Pontzen, Andrew ; Agertz, Oscar LU ; Rey, Martin P. LU ; Read, Justin and Renaud, Florent LU (2024) In Monthly Notices of the Royal Astronomical Society 528(2). p.2346-2357
Abstract

We investigate the impact of a galaxy’s merger history on its system of satellites using the new VINTERGATAN-GM suite of zoom-in hydrodynamical simulations of Milky Way-mass systems. The suite simulates five realizations of the same halo with targeted ‘genetic modifications’ of a z ≈ 2 merger, but resulting in the same halo mass at z = 0. We find that differences in the satellite stellar mass functions last for 2.25−4.25 Gyr after the z ≈ 2 merger; specifically, the haloes that have undergone smaller mergers host up to 60 per cent more satellites than those of the larger merger scenarios. However, by z = 0 these differences in the satellite stellar mass functions have been erased. The differences in satellite numbers seen soon after the... (More)

We investigate the impact of a galaxy’s merger history on its system of satellites using the new VINTERGATAN-GM suite of zoom-in hydrodynamical simulations of Milky Way-mass systems. The suite simulates five realizations of the same halo with targeted ‘genetic modifications’ of a z ≈ 2 merger, but resulting in the same halo mass at z = 0. We find that differences in the satellite stellar mass functions last for 2.25−4.25 Gyr after the z ≈ 2 merger; specifically, the haloes that have undergone smaller mergers host up to 60 per cent more satellites than those of the larger merger scenarios. However, by z = 0 these differences in the satellite stellar mass functions have been erased. The differences in satellite numbers seen soon after the mergers are driven by several factors, including the timings of significant mergers (with M200c mass ratios >1:30 and bringing in M∗ ≥ 108 M☉ at infall), the masses and satellite populations of the central and merging systems, and the subsequent extended history of smaller mergers. The results persist when measured at fixed central stellar mass rather than fixed time, implying that a host’s recent merger history can be a significant source of scatter when reconstructing its dynamical properties from its satellite population.

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author
; ; ; ; and
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
galaxies: dwarf, galaxies: evolution, galaxies: formation, galaxies: interactions
in
Monthly Notices of the Royal Astronomical Society
volume
528
issue
2
pages
12 pages
publisher
Oxford University Press
external identifiers
  • scopus:85184358806
ISSN
0035-8711
DOI
10.1093/mnras/stae129
language
English
LU publication?
yes
id
b82d4241-ce80-4586-b607-b6c53fdf8b0f
date added to LUP
2024-03-08 13:29:43
date last changed
2024-03-08 13:29:43
@article{b82d4241-ce80-4586-b607-b6c53fdf8b0f,
  abstract     = {{<p>We investigate the impact of a galaxy’s merger history on its system of satellites using the new VINTERGATAN-GM suite of zoom-in hydrodynamical simulations of Milky Way-mass systems. The suite simulates five realizations of the same halo with targeted ‘genetic modifications’ of a z ≈ 2 merger, but resulting in the same halo mass at z = 0. We find that differences in the satellite stellar mass functions last for 2.25−4.25 Gyr after the z ≈ 2 merger; specifically, the haloes that have undergone smaller mergers host up to 60 per cent more satellites than those of the larger merger scenarios. However, by z = 0 these differences in the satellite stellar mass functions have been erased. The differences in satellite numbers seen soon after the mergers are driven by several factors, including the timings of significant mergers (with M<sub>200c</sub> mass ratios &gt;1:30 and bringing in M<sub>∗</sub> ≥ 10<sup>8</sup> M<sub>☉</sub> at infall), the masses and satellite populations of the central and merging systems, and the subsequent extended history of smaller mergers. The results persist when measured at fixed central stellar mass rather than fixed time, implying that a host’s recent merger history can be a significant source of scatter when reconstructing its dynamical properties from its satellite population.</p>}},
  author       = {{Joshi, Gandhali D. and Pontzen, Andrew and Agertz, Oscar and Rey, Martin P. and Read, Justin and Renaud, Florent}},
  issn         = {{0035-8711}},
  keywords     = {{galaxies: dwarf; galaxies: evolution; galaxies: formation; galaxies: interactions}},
  language     = {{eng}},
  number       = {{2}},
  pages        = {{2346--2357}},
  publisher    = {{Oxford University Press}},
  series       = {{Monthly Notices of the Royal Astronomical Society}},
  title        = {{VINTERGATAN-GM : How do mergers affect the satellite populations of MW-like galaxies?}},
  url          = {{http://dx.doi.org/10.1093/mnras/stae129}},
  doi          = {{10.1093/mnras/stae129}},
  volume       = {{528}},
  year         = {{2024}},
}