Issue |
A&A
Volume 699, July 2025
|
|
---|---|---|
Article Number | A164 | |
Number of page(s) | 28 | |
Section | Extragalactic astronomy | |
DOI | https://doi.org/10.1051/0004-6361/202347922 | |
Published online | 04 July 2025 |
Dark matter fraction in disk-like galaxies over the past 10 Gyr
1
Department of Physics and Astronomy, University of the Western Cape, Cape Town, 7535
South Africa
2
SISSA International School for Advanced Studies, Via Bonomea 265, I-34136
Trieste, Italy
3
INFN-Sezione di Trieste, Via Valerio 2, I-34127
Trieste, Italy
4
IFPU Institute for Fundamental Physics of the Universe, Via Beirut, 2, 34151
Trieste, Italy
5
University of Strasbourg, CNRS UMR 7550, Observatoire astronomique de Strasbourg, F-67000
Strasbourg, France
6
University of Strasbourg Institute for Advanced Study, 5 allée du Général Rouvillois, F-67083
Strasbourg, France
7
Department of Astrophysics, University of Vienna, Türkenschanzstraße 17, 1180
Vienna, Austria
8
Sterrenkundig Observatorium, Universiteit Gent, Krijgslaan 281 S9, 9000
Gent, Belgium
⋆ Corresponding author: gsharma@unistra.fr, gsharma@uwc.ac.za
Received:
8
September
2023
Accepted:
10
May
2025
We present an observational study of the dark matter fraction in star-forming disk-like galaxies up to redshift z ∼ 2.5 selected from publicly available integral field spectroscopic surveys: KMOS3D, KGES, and KROSS. To model the Hα kinematics of these galaxies, we employed 3D forward modeling, which incorporates beam-smearing and inclination corrections and yields rotation curves. Subsequently, we corrected these rotation curves for gas pressure gradients, resulting in circular velocity curves or ‘intrinsic’ rotation curves. Our final sample comprises 263 rotationally supported galaxies with redshifts ranging from 0.6 ≤ z < 2.5, stellar masses within the range 9.0 ≤ log(Mstar [M⊙]) < 11.5, and star formation rates between 0.49 ≤ log(SFR [M⊙ yr−1]) ≤ 2.5. We estimated the dark matter fraction of these galaxies by subtracting the baryonic mass from the total mass, where the total mass is derived from the intrinsic rotation curves. We provide novel observational evidence suggesting that at a fixed redshift, the dark matter fraction gradually increases with radius such that the outskirts of galaxies are dark matter dominated, similarly to local star-forming disk galaxies. This observed dark matter fraction exhibits a decreasing trend with increasing redshift, and on average, the fraction within the effective radius (up to the outskirts) remains above 50%, similar to the galaxies in the local Universe. We investigated the relationships between dark matter, baryon surface density, and the circular velocity of galaxies. We observed that low stellar mass galaxies, with log(Mstar [M⊙]) ≤ 10.0, undergo a higher degree of evolution, which may be attributed to the hierarchical merging of galaxies. We discuss several sources of uncertainties and current limitations in the field as well as their impact on the measurements of the dark matter fraction and its trend across galactic scales and cosmic time.
Key words: Galaxy: disk / Galaxy: evolution / Galaxy: kinematics and dynamics / galaxies: halos / galaxies: high-redshift
© The Authors 2025
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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