Breathless BEARS: [Oiii] 88µm emission of dusty star-forming galaxies at z = 3−4
Journal article, 2026
We present [O iii] 88 μm observationstowardsfour Herschel-selected dusty star-forming galaxies(DSFGs; log10 μLIR /L☉ = 13.5–14 at z = 2.9–4) using the Atacama Compact Array (ACA) in Bands 9 and 10. We detect [O iii] emission in all four targets at > 3σ, finding line luminosity ratios (L[OIII] /LIR = 10−4.2 to 10−3) similar to local spiral galaxies, and an order of magnitude lower when compared with local dwarf galaxies as well as high-redshift Lyman-break galaxies. Using the short-wavelength capabilities of the ACA, these observations bridge the populations of galaxies with [O iii] emission at low redshift from space missions and at high redshift from ground-based studies. The difference in [O iii] emission between these DSFGs and other high-redshift galaxies reflects their more evolved stellar populations (>10 Myr), larger dustreservoirs(Mdust ∼ 109−11 M☉ ), metal-rich interstellar medium (Z ∼ 0.5–2 Z☉ ), and likely weakerionization radiation fields. Ancillary [C ii] emission on two targets provide L[O iii] /L[C ii] ratios at 0.3–0.9, suggesting that ionized gas represents a smaller fraction of the total gas reservoir in DSFGs, consistent with theoretical models of DSFGs as transitional systems between gas-rich, turbulent disks and more evolved, gas-poor galaxies. Expanding samples of DSFGs with [O iii] emission will be key to place this heterogeneous, poorly understood galactic phase in its astrophysical context.
galaxies: high-redshift
submillimetre: galaxies
galaxies: ISM
Author
Tom Bakx
Chalmers, Space, Earth and Environment, Astronomy and Plasmaphysics
H. Algera
Academia Sinica
Prachi Prajapati
Max Planck Society
University of Cologne
G. J. Bendo
University of Manchester
S. Berta
Institut de Radioastronomie Millimétrique (IRAM)
L. Bonavera
ICTEA
University of Oviedo
P. Cox
Institut d 'Astrophysique de Paris
J. González-Nuevo
University of Oviedo
ICTEA
Masato Hagimoto
Nagoya University
K. C. Harrington
Atacama Large Millimeter-submillimeter Array (ALMA)
National Astronomical Observatory of Japan
European Southern Observatory Santiago
Diego Portales University
M. Lehnert
Institut d 'Astrophysique de Paris
Université de Lyon
S. Serjeant
The Open University
P. Temi
National Aeronautics and Space Administration (NASA)
P. van der Werf
Leiden University
C. Yang
G. De Zotti
Istituto nazionale di astrofisica (INAF)
Monthly Notices of the Royal Astronomical Society
0035-8711 (ISSN) 1365-2966 (eISSN)
Vol. 546 3 stag106Subject Categories (SSIF 2025)
Astronomy, Astrophysics, and Cosmology
DOI
10.1093/mnras/stag106