Investigating the role of turbulence in the interstellar medium in z ∼ 3 dusty star-forming galaxies using kpc-resolution ALMA dust and gas maps
Journal article, 2026
We present ALMA high-resolution ((Formula presented) ) CO(5–4) and CO(4–3) observations of three (Formula presented) submillimetre-selected dusty galaxies from the ALESS survey. These data complement existing (sub)-kpc scale ALMA 870 μm continuum imaging and JWST NIRCam and MIRI imaging from the ALESS-JWST program, allowing us to trace the molecular gas, dust-obscured star formation, and stellar populations on similar spatial scales. We spectroscopically confirm that two of the sources lie at the same redshift and are likely interacting. We find that the molecular-gas distribution broadly follows the dusty star-forming structures seen in the 870 μm dust continuum imaging, but that the gas reservoirs are significantly more extended than the dust emission with a spatial extent comparable to the rest-frame near-infrared stellar emission. By modelling the kinematics for the two highest signal-to-noise sources, we find that the galaxies are well-fit by rotating disc models with high ratios of ordered-to-random motion ((Formula presented) and (Formula presented) ), although smaller-scale kinematic deviations cannot be ruled out at the current sensitivity and spatial resolution. Finally, utilizing the high-resolution 870 μm dust continuum and CO data, we investigate star formation scaling relations on kpc-scales in these high-redshift galaxies. Assuming a constant CO-to-H(Formula presented) conversion factor and excitation ratio, we find that the data are offset from theoretical star formation relation predictions that do not take turbulence into account, but consistent with gravo-turbulent models, thereby suggesting that turbulence plays a central role in regulating star formation at high redshift.
galaxies: star formation
galaxies: evolution
submillimetre: galaxies
Author
B. A. Westoby
Leiden University
J. Hodge
Leiden University
P. Sharda
Leiden University
P. E.Mancera Piña
Leiden University
M. Rybak
Delft University of Technology
Netherlands Institute for Space Research (SRON)
Leiden University
E. da Cunha
University of Western Australia
Australian National University
Juno Li
University of Western Australia
I. Smail
Durham University
A. M. Swinbank
Durham University
A. Battisti
Australian National University
University of Western Australia
Leindert Boogaard
Leiden University
W. N. Brandt
Pennsylvania State University
Eberly College of Science
G. Calistro Rivera
German Aerospace Center (DLR)
European Southern Observatory (ESO)
C. C. Chen
Academia Sinica
East Asian Observatory
P. Cox
Institut d 'Astrophysique de Paris
Misty Cracraft
Space Telescope Science Institute (STScI)
H. Dannerbauer
Instituto de Astrofísica de Canarias
University of La Laguna
R. Decarli
Istituto nazionale di astrofisica (INAF)
T. R. Greve
Cosmic Dawn Center (DAWN)
University College London (UCL)
Technical University of Denmark (DTU)
S. Kendrew
European Space Agency (ESA)
Kirsten Knudsen
Chalmers, Space, Earth and Environment, Astronomy and Plasmaphysics
C. L. Liao
Leiden University
Joshiwa Van Marrewijk
Leiden University
Omnarayani Nayak
National Aeronautics and Space Administration (NASA)
M. Neeleman
National Radio Astronomy Observatory
Lucie Rowland
Leiden University
E. Schinnerer
Max Planck Society
F. Walter
Max Planck Society
J. L. Wardlow
Lancaster University
A. Weiß
Max Planck Society
P. van der Werf
Leiden University
Monthly Notices of the Royal Astronomical Society
0035-8711 (ISSN) 1365-2966 (eISSN)
Vol. 550 4 stag1274Subject Categories (SSIF 2025)
Atom and Molecular Physics and Optics
Astronomy, Astrophysics, and Cosmology
DOI
10.1093/mnras/stag1274