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Do old globular clusters in low-mass galaxies disprove modified gravity?

Published online by Cambridge University Press:  30 October 2025

M. Bílek*
Affiliation:
LERMA, Observatoire de Paris, CNRS, PSL Univ., Sorbonne Univ., 75014 Paris, France Collège de France, 11 place Marcelin Berthelot, 75005 Paris, France Université de Strasbourg, CNRS, Observatoire astronomique de Strasbourg, UMR 7550, F-67000 Strasbourg, France
H. Zhao
Affiliation:
Scottish Universities Physics Alliance, University of St Andrews, North Haugh, St Andrews, Fife KY16 9SS, UK
B. Famaey
Affiliation:
Université de Strasbourg, CNRS, Observatoire astronomique de Strasbourg, UMR 7550, F-67000 Strasbourg, France
S. T. Nagesh
Affiliation:
Université de Strasbourg, CNRS, Observatoire astronomique de Strasbourg, UMR 7550, F-67000 Strasbourg, France
F. Combes
Affiliation:
LERMA, Observatoire de Paris, CNRS, PSL Univ., Sorbonne Univ., 75014 Paris, France Collège de France, 11 place Marcelin Berthelot, 75005 Paris, France
O. Müller
Affiliation:
Institute of Physics, Laboratory of Astrophysics, Ecole Polytechnique Fèdèrale de Lausanne (EPFL), 1290 Sauverny, Switzerland
M. Hilker
Affiliation:
European Southern Observatory, Karl-Schwarzschild-Strasse 2, 85748 Garching bei München, Germany
P. Kroupa
Affiliation:
Helmholtz-Institut für Strahlen- und Kernphysik (HISKP), Universität Bonn, Nußallee 14-16, D-53115 Bonn, Germany Astronomical Institute, Faculty of Mathematics and Physics, Charles University in Prague, V Holešovičkách 2, CZ-18000 Praha, Czech Republic
R. Ibata
Affiliation:
Université de Strasbourg, CNRS, Observatoire astronomique de Strasbourg, UMR 7550, F-67000 Strasbourg, France

Abstract

The controversy “dark matter vs. modified gravity” constitutes a major topic of discussion. It was proposed that dynamical friction could be used to discriminate between the two alternatives. Analytic calculations indicate that, with modified gravity, globular clusters (GCs) of low-mass galaxies experience much stronger dynamical friction than in the equivalent system with Newtonian gravity and dark matter. As a result, in modified gravity the old GCs of low mass galaxies should have already settled in the centers of the galaxies. This is not observed. Here we report on our efforts to verify the analytic results by self-consistent simulations with the MOND-type (modified Newtonian dynamics) gravity. The core stalling mechanism, that was not considered in the analytic calculations, prevents GCs to settle in centers of ultra-diffuse galaxies. For isolated dwarf galaxies, which are gas-rich objects, supernova explosions prevent the GCs from settling.

Information

Type
Poster Paper
Copyright
© The Author(s), 2025. Published by Cambridge University Press on behalf of International Astronomical Union

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References

Bekenstein, J., Milgrom, M., 1984, ApJ, 286, 7.CrossRefGoogle Scholar
Blek, M., Samurovič, S., Renaud, F., 2019, A&A, 625, A32.CrossRefGoogle Scholar
Blek, M., Zhao, H., Famaey, B., Müller, O., Kroupa, P., Ibata, R., 2021, A&A, 653, A170.CrossRefGoogle Scholar
Chan, R., Mamon, G. A., Gerbal, D., 1997, ApL&C, 36, 47 CrossRefGoogle Scholar
Ciotti, L., Binney, J., 2004, MNRAS, 351, 285.CrossRefGoogle Scholar
Dutta Chowdhury, D., van den Bosch, F. C., van Dokkum, P., 2020, ApJ, 903, 149. doi: 10.3847/1538-4357/abb947 CrossRefGoogle Scholar
Famaey, B., McGaugh, S., Milgrom, M., 2018, MNRAS, 480, 473.CrossRefGoogle Scholar
Haghi, H., Kroupa, P., Banik, I., Wu, X., Zonoozi, A. H., Javanmardi, B., Ghari, A., et al., 2019, MNRAS, 487, 2441.CrossRefGoogle Scholar
Kroupa, P., 2015, CaJPh, 93, 169.CrossRefGoogle Scholar
Lelli, F., McGaugh, S. S., Schombert, J. M., Pawlowski, M. S., 2017, ApJ, 836, 152.CrossRefGoogle Scholar
Lüghausen, F., Famaey, B., Kroupa, P., 2015, CaJPh, 93, 232.CrossRefGoogle Scholar
McGaugh, S. S., Lelli, F., Schombert, J. M., 2016, PhRvL, 117, 201101.CrossRefGoogle Scholar
Milgrom, M., 1983, ApJ 270, 365.CrossRefGoogle Scholar
Milgrom, M., 2010, MNRAS, 403, 886.Google Scholar
Milgrom, M., 2019, PRD 99, 044041.CrossRefGoogle Scholar
Sánchez-Salcedo, F. J., Reyes-Iturbide, J., Hernandez, X., 2006, MNRAS, 370, 1829.CrossRefGoogle Scholar
Teyssier, R., 2002, A&A, 385, 337.CrossRefGoogle Scholar