TY - JOUR
T1 - The ALPINE-ALMA [C II] survey
T2 - Molecular gas budget in the early Universe as traced by [C II]
AU - Dessauges-Zavadsky, M.
AU - Ginolfi, M.
AU - Pozzi, F.
AU - Béthermin, M.
AU - Le Fèvre, O.
AU - Fujimoto, S.
AU - Silverman, J. D.
AU - Jones, G. C.
AU - Vallini, L.
AU - Schaerer, D.
AU - Faisst, A. L.
AU - Khusanova, Y.
AU - Fudamoto, Y.
AU - Cassata, P.
AU - Loiacono, F.
AU - Capak, P. L.
AU - Yan, L.
AU - Amorin, R.
AU - Bardelli, S.
AU - Boquien, M.
AU - Cimatti, A.
AU - Gruppioni, C.
AU - Hathi, N. P.
AU - Ibar, E.
AU - Koekemoer, A. M.
AU - Lemaux, B. C.
AU - Narayanan, D.
AU - Oesch, P. A.
AU - Rodighiero, G.
AU - Romano, M.
AU - Talia, M.
AU - Toft, S.
AU - Vergani, D.
AU - Zamorani, G.
AU - Zucca, E.
N1 - Funding Information:
Acknowledgements. 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 Cosmolo-gie 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.
Publisher Copyright:
© 2020 ESO.
PY - 2020/11/1
Y1 - 2020/11/1
N2 - 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 109.7M·, 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 ∼1013M· halos and of more massive z = 0 galaxies in ∼1014M· 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.
AB - 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 109.7M·, 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 ∼1013M· halos and of more massive z = 0 galaxies in ∼1014M· 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.
KW - Galaxies: ISM
KW - Galaxies: evolution
KW - Galaxies: high-redshift
KW - ISM: molecules
UR - http://www.scopus.com/inward/record.url?scp=85095132436&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85095132436&partnerID=8YFLogxK
U2 - 10.1051/0004-6361/202038231
DO - 10.1051/0004-6361/202038231
M3 - Review article
AN - SCOPUS:85095132436
SN - 0004-6361
VL - 643
JO - Astronomy and Astrophysics
JF - Astronomy and Astrophysics
M1 - A5
ER -