V z -GAL: Probing Cold Molecular Gas in Dusty Star-forming Galaxies at z = 1–6
Year: 2026
Type: article
Abstract: We present the first results of V z -GAL, a high-redshift CO( J = 1–0) large survey with the Karl G. Jansky Very Large Array, targeting 92 Herschel-selected, infrared-luminous, dusty star-forming galaxies at redshifts 1–6. These sources are selected based on having redshifts and mid-/high- J CO transitions from the NOrthern Extended Millimeter Array z –GAL survey. We successfully detect CO( J = 1–0) emission in 90/92 galaxies at the expected positions and redshifts, including nine tentative detections at 2 σ –3 σ significance, and CO( J = 2–1) emission in 10 of these galaxies. The CO( J = 1–0) luminosities suggest apparent gas masses in the range μ M H 2 = (2–20) × 10 11 ( α CO /4.0) M ⊙ , which implies gas depletion times of 50–600 Myr. These timescales show similar spread as local ULIRGs, suggesting a self-regulatory mechanism that maintains a consistent star formation rate per unit gas mass in starbursts across redshifts. To quantify the contribution of “excitation correction” factors to gas mass estimates, we calculate median CO line brightness temperature ratios of r 21 = 0.88 ± 0.25, r 31 = 0.61 ± 0.22, r 41 = 0.49 ± 0.15, r 51 = 0.47 ± 0.13, and r 61 = 0.28 ± 0.13. Accounting for these corrections results in a reduced scatter in “gas mass–star formation rate” relations. We also find a median log( L ′ [ CI ] ( 3 P 1 − 3 P 0 ) / L ′ CO ( J = 1 − 0 ) ) = − 0.71 ± 0.12 for a subsample of 23 sources, consistent with the ratios derived for local star-forming galaxies. Together, our findings are in agreement with common conditions in the cold gas reservoirs among star-forming galaxies over a broad range in star formation modes, efficiencies, and scales.
Authors: Prachi Prajapati, Dominik Riechers, Pierre Cox, Axel Weiss, Amélie Saintonge, Bethany Jones, Tom J. L. C. Bakx, Stefano Berta, Paul van der Werf, Roberto Neri, Kirsty M. Butler, Asantha Cooray, Diana Ismail, Andrew J. Baker, Edoardo Borsato, Andrew Harris, Rob Ivison, Matthew Lehnert, Lucia Marchetti, Hugo Messias, Alain Omont, Catherine Vlahakis, Chentao Yang
Institutions: University of Cologne, Max Planck Institute for Radio Astronomy, Centre National de la Recherche Scientifique, Institut d'Astrophysique de Paris, Sorbonne Université, Chalmers University of Technology, Institut de Radioastronomie Millimétrique, Leiden University, Leiden Observatory, University of California, Irvine, Observatoire astronomique de Strasbourg, Université de Strasbourg, Rutgers, The State University of New Jersey, University of the Western Cape, University of Padua, University of Maryland, College Park, Dublin Institute For Advanced Studies, Royal Observatory, University of Edinburgh, Lyon 1 Université, Centre de Recherche Astrophysique de Lyon, University of Cape Town, Istituto di Radioastronomia di Bologna, Inter-university Institute for Data Intensive Astronomy, Atacama Large Millimeter Submillimeter Array, European Southern Observatory, National Radio Astronomy Observatory
Language: English
Subfield: Astronomy and Astrophysics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $4,499
Funders: National Science Foundation, National Radio Astronomy Observatory, Department of Science and Innovation, South Africa, International Max Planck Research School for Environmental, Cellular and Molecular Microbiology, National Research Foundation, Deutsche Forschungsgemeinschaft, Agence Nationale de la Recherche, International Max Planck Research School for Advanced Methods in Process and Systems Engineering
OpenAlex ID: W4417023931