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Galactoseismology in cosmological simulations Vertical perturbations by dark matter, satellite galaxies, and gas

García-Conde, B. ; Antoja, T. ; Roca-Fàbrega, S. LU orcid ; Gómez, F. ; Ramos, P. ; Garavito-Camargo, N. and Gómez-Flechoso, M. A. (2024) In Astronomy and Astrophysics 683.
Abstract

Context. Complex models recently became available for studying the dynamics of disk galaxies such as the Milky Way (MW). These models include the global dynamics from dwarf satellite galaxies, dark matter halo structure, gas infall, and stellar disks in a cosmological context. Aims. We use a MW model from a suite of high-resolution hydrodynamical cosmological simulations named GARROTXA to establish the relationship between the vertical disturbances seen in its galactic disk and multiple perturbations from the dark matter halo, satellites, and gas. Methods. We calculated the bending modes in the galactic disk in the last 6 Gyr of evolution. We computed the vertical acceleration exerted by dark matter and gas in order to quantify the... (More)

Context. Complex models recently became available for studying the dynamics of disk galaxies such as the Milky Way (MW). These models include the global dynamics from dwarf satellite galaxies, dark matter halo structure, gas infall, and stellar disks in a cosmological context. Aims. We use a MW model from a suite of high-resolution hydrodynamical cosmological simulations named GARROTXA to establish the relationship between the vertical disturbances seen in its galactic disk and multiple perturbations from the dark matter halo, satellites, and gas. Methods. We calculated the bending modes in the galactic disk in the last 6 Gyr of evolution. We computed the vertical acceleration exerted by dark matter and gas in order to quantify the impact of these components on the disk, and compared this with the bending behavior with Fourier analysis. Results. We find complex bending patterns at different radii and times, such as an inner retrograde mode with high frequency and an outer slower retrograde mode excited at different times. The amplitudes of these bending modes are highest during the early stages of formation of the thin disk (20 km s−1) and reach up to 8.5 km s−1 in the late disk evolution. We find that the infall of satellite galaxies leads to a tilt of the disk, and produces strong anisotropic gas accretion with a misalignment of 8 with subsequent star formation events and supernovae, creating significant vertical accelerations on the disk plane. The misalignment between the disk and the inner stellar and dark matter triaxial structure, which formed during the ancient assembly of the galaxy, also leads to a strong vertical acceleration of the stars. We also find dark matter subhalos that temporally coincide with the appearance of bending waves in certain periods. Conclusions. We conclude that several agents trigger the bending of the stellar disk and its phase spirals in this simulation, including satellite galaxies, dark subhalos, misaligned gaseous structures, and the inner dark matter profile. These phenomena coexist and influence each other, sometimes making it challenging to establish direct causality.

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author
; ; ; ; ; and
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
galaxies: evolution, Galaxy: kinematics and dynamics, methods: numerical, stars: kinematics and dynamics
in
Astronomy and Astrophysics
volume
683
publisher
EDP Sciences
external identifiers
  • scopus:85187119124
ISSN
0004-6361
DOI
10.1051/0004-6361/202347446
language
English
LU publication?
yes
id
c89872f0-3b03-4143-b368-a7e75f9b623e
date added to LUP
2024-04-12 10:41:11
date last changed
2024-05-16 11:09:20
@article{c89872f0-3b03-4143-b368-a7e75f9b623e,
  abstract     = {{<p>Context. Complex models recently became available for studying the dynamics of disk galaxies such as the Milky Way (MW). These models include the global dynamics from dwarf satellite galaxies, dark matter halo structure, gas infall, and stellar disks in a cosmological context. Aims. We use a MW model from a suite of high-resolution hydrodynamical cosmological simulations named GARROTXA to establish the relationship between the vertical disturbances seen in its galactic disk and multiple perturbations from the dark matter halo, satellites, and gas. Methods. We calculated the bending modes in the galactic disk in the last 6 Gyr of evolution. We computed the vertical acceleration exerted by dark matter and gas in order to quantify the impact of these components on the disk, and compared this with the bending behavior with Fourier analysis. Results. We find complex bending patterns at different radii and times, such as an inner retrograde mode with high frequency and an outer slower retrograde mode excited at different times. The amplitudes of these bending modes are highest during the early stages of formation of the thin disk (20 km s<sup>−1</sup>) and reach up to 8.5 km s<sup>−1</sup> in the late disk evolution. We find that the infall of satellite galaxies leads to a tilt of the disk, and produces strong anisotropic gas accretion with a misalignment of 8<sup>◦</sup> with subsequent star formation events and supernovae, creating significant vertical accelerations on the disk plane. The misalignment between the disk and the inner stellar and dark matter triaxial structure, which formed during the ancient assembly of the galaxy, also leads to a strong vertical acceleration of the stars. We also find dark matter subhalos that temporally coincide with the appearance of bending waves in certain periods. Conclusions. We conclude that several agents trigger the bending of the stellar disk and its phase spirals in this simulation, including satellite galaxies, dark subhalos, misaligned gaseous structures, and the inner dark matter profile. These phenomena coexist and influence each other, sometimes making it challenging to establish direct causality.</p>}},
  author       = {{García-Conde, B. and Antoja, T. and Roca-Fàbrega, S. and Gómez, F. and Ramos, P. and Garavito-Camargo, N. and Gómez-Flechoso, M. A.}},
  issn         = {{0004-6361}},
  keywords     = {{galaxies: evolution; Galaxy: kinematics and dynamics; methods: numerical; stars: kinematics and dynamics}},
  language     = {{eng}},
  month        = {{03}},
  publisher    = {{EDP Sciences}},
  series       = {{Astronomy and Astrophysics}},
  title        = {{Galactoseismology in cosmological simulations Vertical perturbations by dark matter, satellite galaxies, and gas}},
  url          = {{http://dx.doi.org/10.1051/0004-6361/202347446}},
  doi          = {{10.1051/0004-6361/202347446}},
  volume       = {{683}},
  year         = {{2024}},
}