ALMA Chemical Evolution (ACE) survey: dust-to-gas ratios in sub-solar metallicity galaxies at cosmic noon
Abstract
Dust is a fundamental component of the interstellar medium and provides a key tracer of the baryon cycle that regulates galaxy evolution. The dust-to-gas ratio links metals in the gas phase to those locked into dust grains, making it a sensitive diagnostic of dust production, grain growth, and destruction. We present measurements of the dust-to-molecular-gas ratio (DGRmol), for typical star-forming galaxies (log M⋆ ≈ 10) at sub-solar metallicites, at z≃2−2.5 from the ALMA Chemical Evolution (ACE) survey. By combining ALMA CO and dust-continuum observations with robust gas-phase metallicity measurements, ACE extends direct dust and molecular-gas measurements to lower stellar masses and lower metallicities than previously available at this epoch, reaching down to 0.4 Z⊙. This enables the first constraints on the DGRmol--metallicity relation for typical unlensed galaxies at cosmic noon. We find that DGRmol increases with metallicity, with a log-space slope of 1.2 ± 0.7, indicating that metal-poor galaxies have systematically lower DGRmol than their more metal-rich counterparts. For the detected ACE galaxies, we measure a mean value of log10(Mdust/Mmol)=−2.37±0.05 for a mean metallicity of 12+log (O/H) = 8.45 ± 0.02. We find agreement with DGRmol in the local Universe at fixed metallicities, indicating that the same dust-growth physics, likely grain growth in the ISM, dominates at metallicities of 8.3 ≤ 12+log(O/H) ≤ 8.7 at cosmic noon. These measurements provide novel empirical constraints for models of dust enrichment and galaxy evolution during the peak epoch of cosmic star formation. Additionally, ACE provides a sub-solar metallicity reference for the calibration of dust continuum as tracer of molecular gas, essential for studying metal-poor, high-redshift systems.
Related
- ALMA Chemical Evolution (ACE) Survey: Molecular gas properties of low-mass, low-metallicity galaxies at cosmic noon
- ALMA Chemical Evolution (ACE) survey: the dust content of subsolar metallicity galaxies at cosmic noon
- ALMA Chemical Evolution (ACE) survey: The gas fundamental metallicity relation at cosmic noon
- JADES: the mass-metallicity relation at z=1−10. New calibrations, extremely metal-poor galaxies, and chemical diversity
- Constraints on the Metallicity-dependent Explodability of Massive Stars from Galactic Chemical Evolution: Toward Alleviating the Red Supergiant Problem
BibTeX
@misc{geesink2026alma,
title = {{ALMA Chemical Evolution (ACE) survey: dust-to-gas ratios in sub-solar metallicity galaxies at cosmic noon}},
author = {N. N. Geesink and G. Popping and L. A. Boogaard and I. Langan and A. Pope and R. Popescu and I. Shivaei and M. Solimano and M. Kaasinen and B. Mobasher and D. Narayanan and M. Parente and N. Reddy and R. L. Sanders},
howpublished = {arXiv},
year = {2026},
month = sep,
doi = {10.48550/arxiv.2609.20926},
eprint = {2609.20926},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2609.20926},
note = {CC BY 4.0},
}
RIS
TY - UNPB
TI - ALMA Chemical Evolution (ACE) survey: dust-to-gas ratios in sub-solar metallicity galaxies at cosmic noon
AU - N. N. Geesink
AU - G. Popping
AU - L. A. Boogaard
AU - I. Langan
AU - A. Pope
AU - R. Popescu
AU - I. Shivaei
AU - M. Solimano
AU - M. Kaasinen
AU - B. Mobasher
AU - D. Narayanan
AU - M. Parente
AU - N. Reddy
AU - R. L. Sanders
PY - 2026
DA - 2026/09/17
PB - arXiv
DO - 10.48550/arxiv.2609.20926
UR - https://arxiv.org/abs/2609.20926
AB - Dust is a fundamental component of the interstellar medium and provides a key tracer of the baryon cycle that regulates galaxy evolution. The dust-to-gas ratio links metals in the gas phase to those locked into dust grains, making it a sensitive diagnostic of dust production, grain growth, and destruction. We present measurements of the dust-to-molecular-gas ratio (DGR_mol), for typical star-forming galaxies (log M_⋆ ≈ 10) at sub-solar metallicites, at z≃2−2.5 from the ALMA Chemical Evolution (ACE) survey. By combining ALMA CO and dust-continuum observations with robust gas-phase metallicity measurements, ACE extends direct dust and molecular-gas measurements to lower stellar masses and lower metallicities than previously available at this epoch, reaching down to 0.4 Z_⊙. This enables the first constraints on the DGR_mol--metallicity relation for typical unlensed galaxies at cosmic noon. We find that DGR_mol increases with metallicity, with a log-space slope of 1.2 ± 0.7, indicating that metal-poor galaxies have systematically lower DGR_mol than their more metal-rich counterparts. For the detected ACE galaxies, we measure a mean value of log_10(M_dust/M_mol)=−2.37±0.05 for a mean metallicity of 12+log (O/H) = 8.45 ± 0.02. We find agreement with DGR_mol in the local Universe at fixed metallicities, indicating that the same dust-growth physics, likely grain growth in the ISM, dominates at metallicities of 8.3 ≤ 12+log(O/H) ≤ 8.7 at cosmic noon. These measurements provide novel empirical constraints for models of dust enrichment and galaxy evolution during the peak epoch of cosmic star formation. Additionally, ACE provides a sub-solar metallicity reference for the calibration of dust continuum as tracer of molecular gas, essential for studying metal-poor, high-redshift systems.
ER -