The ALPINE-ALMA [C II] survey

Astronomy and Astrophysics, vol. 643, pp. A5

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 μ m 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 μ m luminosities extrapolated from the rest-frame 158 μ m 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) × 10 8 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 ∼10 13 M ⊙ halos and of more massive z = 0 galaxies in ∼10 14 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.

Authors 33

1. Miroslava Dessauges-Zavadsky

   University of Geneva

   Affiliation as printed

   Observatoire de Genève, Université de Genève, 51 Ch. des Maillettes, 1290 Versoix, Switzerland

2. M. Ginolfi

   University of Geneva

   Affiliation as printed

   Observatoire de Genève, Université de Genève, 51 Ch. des Maillettes, 1290 Versoix, Switzerland

3. Francesca Pozzi

   Osservatorio di Astrofisica e Scienza dello Spazio · University of Bologna

   Affiliation as printed

   INAF – Osservatorio di Astrofisica e Scienza dello Spazio di Bologna, Via Gobetti 93/3, 40129 Bologna, Italy

   Università di Bologna – Dipartimento di Fisica e Astronomia, Via Gobetti 93/2, 40129 Bologna, Italy

4. M. Béthermin

   Centre National de la Recherche Scientifique · Aix-Marseille Université · Laboratoire d’Astrophysique de Marseille

   Affiliation as printed

   Aix Marseille Université, CNRS, LAM (Laboratoire d’Astrophysique de Marseille) UMR 7326, 13388 Marseille, France

   Aix Marseille Université, CNRS, LAM (Laboratoire d'Astrophysique de Marseille) UMR 7326, 13388 Marseille, France

5. Olivier Le Fèvre

   Centre National de la Recherche Scientifique · Aix-Marseille Université · Laboratoire d’Astrophysique de Marseille

   Affiliation as printed

   Aix Marseille Université, CNRS, LAM (Laboratoire d’Astrophysique de Marseille) UMR 7326, 13388 Marseille, France

   Aix Marseille Université, CNRS, LAM (Laboratoire d'Astrophysique de Marseille) UMR 7326, 13388 Marseille, France

6. Seiji Fujimoto

   University of Copenhagen

   Affiliation as printed

   Niels Bohr Institute, University of Copenhagen, Lyngbyvej 2, 2100 Copenhagen, Denmark

   The Cosmic Dawn Center, University of Copenhagen, Vibenshuset, Lyngbyvej 2, 2100 Copenhagen, Denmark

7. John D. Silverman

   Kavli Institute for the Physics and Mathematics of the Universe · The University of Tokyo

   Affiliation as printed

   Department of Astronomy, School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo, Tokyo, 113-0033 Japan

   Kavli Institute for the Physics and Mathematics of the Universe, The University of Tokyo (Kavli IPMU, WPI), 277-8583 Kashiwa, Japan

8. Gareth C. Jones

   University of Cambridge

   Affiliation as printed

   Cavendish Laboratory, University of Cambridge, 19 J. J. Thomson Ave., Cambridge, CB3 0HE UK

   Kavli Institute for Cosmology, University of Cambridge, Madingley Road, Cambridge, CB3 0HA UK

9. Livia Vallini Aachen Leiden Observatory

   Leiden University · Leiden Observatory

   Affiliation as printed

   Leiden Observatory, Leiden University, PO Box 9500, 2300 RA Leiden, The Netherlands

10. D. Schaerer

    University of Geneva

    Affiliation as printed

    Observatoire de Genève, Université de Genève, 51 Ch. des Maillettes, 1290 Versoix, Switzerland

11. Andreas L. Faisst

    California Institute of Technology · Infrared Processing and Analysis Center

    Affiliation as printed

    IPAC, M/C 314-6, California Institute of Technology, 1200 East California Boulevard, Pasadena, CA, 91125 USA

12. Yana Khusanova

    Centre National de la Recherche Scientifique · Aix-Marseille Université · Laboratoire d’Astrophysique de Marseille · Max Planck Institute for Astronomy

    Affiliation as printed

    Aix Marseille Université, CNRS, LAM (Laboratoire d’Astrophysique de Marseille) UMR 7326, 13388 Marseille, France

    Max-Planck-Institut für Astronomie, Königstuhl 17, 69117 Heidelberg, Germany

    Aix Marseille Université, CNRS, LAM (Laboratoire d'Astrophysique de Marseille) UMR 7326, 13388 Marseille, France

13. Yoshinobu Fudamoto

    University of Geneva

    Affiliation as printed

    Observatoire de Genève, Université de Genève, 51 Ch. des Maillettes, 1290 Versoix, Switzerland

14. P. Cassata

    University of Padua · Osservatorio Astronomico di Padova · National Institute for Astrophysics

    Affiliation as printed

    Dipartimento di Fisica e Astronomia, Università di Padova, Vicolo dell’Osservatorio, 3, 35122 Padova, Italy

    INAF – Osservatorio Astronomico di Padova, Vicolo dell’Osservatorio 5, 35122 Padova, Italy

    Dipartimento di Fisica e Astronomia, Università di Padova, Vicolo dell'Osservatorio, 3, 35122 Padova, Italy

    INAF – Osservatorio Astronomico di Padova, Vicolo dell'Osservatorio 5, 35122 Padova, Italy

15. F. Loiacono

    Osservatorio di Astrofisica e Scienza dello Spazio · University of Bologna

    Affiliation as printed

    INAF – Osservatorio di Astrofisica e Scienza dello Spazio di Bologna, Via Gobetti 93/3, 40129 Bologna, Italy

    Università di Bologna – Dipartimento di Fisica e Astronomia, Via Gobetti 93/2, 40129 Bologna, Italy

16. P. Capak

    California Institute of Technology · University of Copenhagen · Infrared Processing and Analysis Center

    Affiliation as printed

    IPAC, M/C 314-6, California Institute of Technology, 1200 East California Boulevard, Pasadena, CA, 91125 USA

    Niels Bohr Institute, University of Copenhagen, Lyngbyvej 2, 2100 Copenhagen, Denmark

    The Cosmic Dawn Center, University of Copenhagen, Vibenshuset, Lyngbyvej 2, 2100 Copenhagen, Denmark

17. L. Yan

    California Institute of Technology

    Affiliation as printed

    The Caltech Optical Observatories, California Institute of Technology, Pasadena, CA, 91125 USA

18. R. Amorín

    University of La Serena

    Affiliation as printed

    Departamento de Astronomía, Universidad de La Serena, Av. Juan Cisternas 1200 Norte, La Serena, Chile

    Instituto de Investigación Multidisciplinar en Ciencia y Tecnología, Universidad de La Serena, Raúl Bitrán, 1305 La Serena, Chile

19. S. Bardelli

    Osservatorio di Astrofisica e Scienza dello Spazio

    Affiliation as printed

    INAF – Osservatorio di Astrofisica e Scienza dello Spazio di Bologna, Via Gobetti 93/3, 40129 Bologna, Italy

20. Médéric Boquien

    Universidad de Antofagasta

    Affiliation as printed

    Centro de Astronomía (CITEVA), Universidad de Antofagasta, Avenida Angamos 601, Antofagasta, Chile

21. A. Cimatti

    Arcetri Astrophysical Observatory · University of Bologna

    Affiliation as printed

    INAF – Osservatorio Astrofisico di Arcetri, Largo E. Fermi 5, 50125 Firenze, Italy

    Università di Bologna – Dipartimento di Fisica e Astronomia, Via Gobetti 93/2, 40129 Bologna, Italy

22. Nimish P. Hathi

    Space Telescope Science Institute

    Affiliation as printed

    Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD, 21218 USA

23. E. Ibar

    University of Valparaíso

    Affiliation as printed

    Instituto de Física y Astronomía, Universidad de Valparaíso, Avda. Gran Bretaña 1111, Valparaíso, Chile

24. Anton M. Koekemoer

    Space Telescope Science Institute

    Affiliation as printed

    Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD, 21218 USA

25. Brian C. Lemaux

    University of California, Davis

    Affiliation as printed

    Department of Physics, University of California, Davis, One Shields Ave., Davis, CA, 95616 USA

26. D. Narayanan

    University of Florida

    Affiliation as printed

    Department of Astronomy, University of Florida, 211 Bryant Space Sciences Center, Gainesville, FL, 32611 USA

27. Pascal A. Oesch

    University of Geneva · University of Copenhagen

    Affiliation as printed

    Observatoire de Genève, Université de Genève, 51 Ch. des Maillettes, 1290 Versoix, Switzerland

    The Cosmic Dawn Center, University of Copenhagen, Vibenshuset, Lyngbyvej 2, 2100 Copenhagen, Denmark

28. Giulia Rodighiero

    University of Padua · Osservatorio Astronomico di Padova · National Institute for Astrophysics

    Affiliation as printed

    Dipartimento di Fisica e Astronomia, Università di Padova, Vicolo dell’Osservatorio, 3, 35122 Padova, Italy

    INAF – Osservatorio Astronomico di Padova, Vicolo dell’Osservatorio 5, 35122 Padova, Italy

    Dipartimento di Fisica e Astronomia, Università di Padova, Vicolo dell'Osservatorio, 3, 35122 Padova, Italy

    INAF – Osservatorio Astronomico di Padova, Vicolo dell'Osservatorio 5, 35122 Padova, Italy

29. M. Talia

    Osservatorio di Astrofisica e Scienza dello Spazio · University of Bologna

    Affiliation as printed

    INAF – Osservatorio di Astrofisica e Scienza dello Spazio di Bologna, Via Gobetti 93/3, 40129 Bologna, Italy

    Università di Bologna – Dipartimento di Fisica e Astronomia, Via Gobetti 93/2, 40129 Bologna, Italy

30. Sune Toft

    University of Copenhagen

    Affiliation as printed

    Niels Bohr Institute, University of Copenhagen, Lyngbyvej 2, 2100 Copenhagen, Denmark

    The Cosmic Dawn Center, University of Copenhagen, Vibenshuset, Lyngbyvej 2, 2100 Copenhagen, Denmark

31. Daniela Vergani

    Osservatorio di Astrofisica e Scienza dello Spazio

    Affiliation as printed

    INAF – Osservatorio di Astrofisica e Scienza dello Spazio di Bologna, Via Gobetti 93/3, 40129 Bologna, Italy

32. G. Zamorani

    Osservatorio di Astrofisica e Scienza dello Spazio

    Affiliation as printed

    INAF – Osservatorio di Astrofisica e Scienza dello Spazio di Bologna, Via Gobetti 93/3, 40129 Bologna, Italy

33. Elena Zucca

    Osservatorio di Astrofisica e Scienza dello Spazio

    Affiliation as printed

    INAF – Osservatorio di Astrofisica e Scienza dello Spazio di Bologna, Via Gobetti 93/3, 40129 Bologna, Italy