CaltechAUTHORS
Published November 2020 | Version Accepted Version + Published
Journal Article Open

The ALPINE-ALMA [C II] survey. Molecular gas budget in the early Universe as traced by [C II]

Creators

  • 1. ROR icon University of Geneva
  • 2. ROR icon University of Bologna
  • 3. ROR icon Aix-Marseille University
  • 4. ROR icon University of Copenhagen
  • 5. ROR icon Kavli Institute for the Physics and Mathematics of the Universe
  • 6. ROR icon University of Tokyo
  • 7. ROR icon University of Cambridge
  • 8. ROR icon Leiden University
  • 9. ROR icon Infrared Processing and Analysis Center
  • 10. ROR icon Max Planck Institute for Astronomy
  • 11. ROR icon University of Padua
  • 12. ROR icon Osservatorio Astronomico di Padova
  • 13. ROR icon California Institute of Technology
  • 14. ROR icon University of La Serena
  • 15. ROR icon University of Antofagasta
  • 16. ROR icon Arcetri Astrophysical Observatory
  • 17. ROR icon Space Telescope Science Institute
  • 18. ROR icon University of Valparaíso
  • 19. ROR icon University of California, Davis
  • 20. ROR icon University of Florida

Abstract

The molecular gas content of normal galaxies at z >  4 is poorly constrained because the commonly used molecular gas tracers become hard to detect at these high redshifts. We use the [C II] 158 μm luminosity, which was recently proposed as a molecular gas tracer, to estimate the molecular gas content in a large sample of main sequence star-forming galaxies at z = 4.4 − 5.9, with a median stellar mass of 10^(9.7) M_⊙, drawn from the ALMA Large Program to INvestigate [C II] at Early times survey. The agreement between the molecular gas masses derived from [C II] luminosities, dynamical masses, and rest-frame 850 μm luminosities extrapolated from the rest-frame 158 μm continuum supports [C II] as a reliable tracer of molecular gas in our sample. We find a continuous decline of the molecular gas depletion timescale from z = 0 to z = 5.9, which reaches a mean value of (4.6 ± 0.8) × 10⁸ yr at z ∼ 5.5, only a factor of between two and three shorter than in present-day galaxies. This suggests a mild enhancement of the star formation efficiency toward high redshifts. Our estimates also show that the previously reported rise in the molecular gas fraction flattens off above z ∼ 3.7 to achieve a mean value of 63%±3% over z = 4.4 − 5.9. This redshift evolution of the gas fraction is in line with that of the specific star formation rate. We use multi-epoch abundance-matching to follow the gas fraction evolution across cosmic time of progenitors of z = 0 Milky Way-like galaxies in ∼10¹³ M_⊙ halos and of more massive z = 0 galaxies in ∼10¹⁴ M⊙ halos. Interestingly, the former progenitors show a monotonic increase of the gas fraction with redshift, while the latter show a steep rise from z = 0 to z ∼ 2 followed by a constant gas fraction from z ∼ 2 to z = 5.9. We discuss three possible effects, namely outflows, a pause in gas supply, and over-efficient star formation, which may jointly contribute to the gas fraction plateau of the latter massive galaxies.

Additional Information

© 2020 ESO. Article published by EDP Sciences. Received 22 April 2020; Accepted 17 July 2020; Published online 27 October 2020. This paper is dedicated to the memory of Olivier Le Fèvre, PI of the ALPINE survey. The ALPINE survey is based on data obtained with the ALMA Observatory, under Large Program 2017.1.00428.L. ALMA is a partnership of ESO (representing its member states), NSF (USA) and NINS (Japan), together with NRC (Canada), MOST and ASIAA (Taiwan), and KASI (Republic of Korea), in cooperation with the Republic of Chile. The Joint ALMA Observatory is operated by ESO, AUI/NRAO and NAOJ. This program receives financial support from the French CNRS-INSU Programme National Cosmologie et Galaxies. F.P., F.L., A.C., C.G., and M.T. acknowledge the support from grant PRIN MIUR 2017 – 20173ML3WW_s. S.F. is supported by the Cosmic Dawn Center of Excellence funded by the Danish National Research Foundation under the grant No. 140. J.D.S is supported by the JSPS KAKENHI Grant Number JP18H04346, and the World Premier International Research Center Initiative (WPI Initiative), MEXT, Japan. G.C.J. acknowledges ERC Advanced Grant 695671 "QUENCH" and support by the Science and Technology Facilities Council (STFC). M.B. acknowledges FONDECYT regular grant 1170618. E.I. acknowledges partial support from FONDECYT through grant No. 1171710. S.T. acknowledges support from the European Research Council (ERC) Consolidator Grant funding scheme (project "ConTExt", grant number: 648179). The Cosmic Dawn Center (DAWN) is funded by the Danish National Research Foundation under grant No. 140. L.V. acknowledges funding from the European Union's Horizon 2020 research and innovation program under the Marie Sklodowska-Curie Grant agreement No. 746119. We are grateful to the anonymous referee for providing a thorough report, which contributed to improve the quality paper.

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Published - aa38231-20.pdf

Accepted Version - 2004.10771.pdf

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Additional details

Identifiers

Eprint ID
106330
Resolver ID
CaltechAUTHORS:20201028-123903558

Related works

Describes
https://arxiv.org/abs/2004.10771 (URL)

Funding

Centre National de la Recherche Scientifique (CNRS)
Institut National des Sciences de l'Univers (INSU)
Ministero dell'Istruzione, dell'Università e della Ricerca (MIUR)
20173ML3WW_s
Danish National Research Foundation
140
Japan Society for the Promotion of Science (JSPS)
JP18H04346
Ministry of Education, Culture, Sports, Science and Technology (MEXT)
European Research Council (ERC)
695671
Science and Technology Facilities Council (STFC)
Fondo Nacional de Desarrollo Científico y Tecnológico (FONDECYT)
1170618
Fondo Nacional de Desarrollo Científico y Tecnológico (FONDECYT)
1171710
European Research Council (ERC)
648179
Marie Curie Fellowship
746119

Dates

Created
2020-10-29
Created from EPrint's datestamp field
Updated
2021-11-16
Created from EPrint's last_modified field

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Infrared Processing and Analysis Center (IPAC)