Issue |
A&A
Volume 690, October 2024
|
|
---|---|---|
Article Number | A119 | |
Number of page(s) | 18 | |
Section | Extragalactic astronomy | |
DOI | https://doi.org/10.1051/0004-6361/202449666 | |
Published online | 03 October 2024 |
Globular cluster orbital decay in dwarf galaxies with MOND and CDM: Impact of supernova feedback
1
Observatoire de Paris, LERMA, Collège de France, CNRS, PSL University, Sorbonne University F-75014, Paris
2
FZU – Institute of Physics of the Czech Academy of Sciences, Na Slovance 1999/2 Prague 182 21, Czech Republic
3
Strasbourg University, CNRS, Observatoire astronomique de Strasbourg, F-67000 Strasbourg, France
4
European Southern Observatory, Karl-Schwarzschild-Strasse 2, 85748 Garching bei München, Germany
Received:
19
February 2024
Accepted:
11
June 2024
Dynamical friction works very differently for Newtonian gravity with dark matter and in modified Newtonian dynamics (MOND). While the absence of dark matter considerably reduces the friction in major galaxy mergers, analytic calculations indicate the opposite for very small perturbations, such as globular clusters (GCs) sinking in dwarf galaxies. Here, we study the decay of GCs in isolated gas-rich dwarf galaxies using simulations with the Phantom of Ramses code, which enables both the Newtonian and the QUMOND MOND gravity. We modeled the GCs as point masses, and we simulated the full hydrodynamics, with star formation and supernovae feedback. We explored whether the fluctuations in gravitational potential caused by the supernovae can prevent GCs from sinking toward the nucleus. For GCs of typical mass or lighter, we find that this indeed works in both Newtonian and MOND simulations. The GC can even make a random walk. However, we find that supernovae cannot prevent massive GCs (M ≥ 4 × 105 M⊙) from sinking in MOND. The resulting object looks similar to a galaxy with an offset core, which embeds the sunk GC. The problem is much milder in the Newtonian simulations. This result thus favors Newtonian over QUMOND gravity, but we note that it relies on the correctness of the difficult modeling of baryonic feedback. We propose that the fluctuations in the gravitational potential could be responsible for the thickness of the stellar disks of dwarf galaxies and that strong supernova winds in modified gravity can transform dwarf galaxies into ultra-diffuse galaxies.
Key words: galaxies: dwarf / galaxies: evolution / galaxies: kinematics and dynamics / galaxies: star clusters: general / dark matter
© The Authors 2024
Open Access article, published by EDP Sciences, under the terms of the Creative Commons Attribution License (https://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
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