Year: 2026
Type: article
Abstract: Luminosity functions (LF) are some of the most basic quantities providing insights into galaxy evolution across cosmic time and enabling a direct comparison between observations and simulations. Here, we present the first [C ii] 158 μm LF at z ∼ 7 from a sizeable UV-selected ALMA sample. Our analysis makes use of 27 galaxies with significant [C ii] emission line detections in the epoch of reionization from the REBELS (Reionization Era Bright Emission Line Survey) ALMA Large Program and its pilot programs. We used these line detections and similar from ALPINE to calibrate UV luminosity-$L_\mathrm{[C\, {\small ii}] }$ and stellar mass-$L_\mathrm{[C\, {\small ii}] }$ relations at z ∼ 7. Given the challenge in precisely defining a selection volume for the REBELS sample itself, we rely on published UV LF and stellar mass function (SMF) determinations at z ∼ 7 and three complementary approaches to derive the [C ii] LF. The UV LF-based method provides a lower limit on the [C ii] LF, due to its missing the most dust-obscured systems. Our SMF-based estimate yields a Schechter function with a characteristic luminosity of $L^*_\mathrm{[C\, {\small ii}] }=10^{9.11_{-0.27}^{+0.11}}\, L_\odot$ and a steep faint-end slope. From z ∼ 7 to z ∼ 5, our inferred [C ii] LF shows an evolution of +0.3 dex in normalisation and +0.1 dex in $L^*_\mathrm{[C\, {\small ii}] }$. Our results indicate a general underprediction from models of the abundance of [C ii] emitters at high-redshift and thus potentially the number densities of massive yet UV-faint systems implied by our SMF-based method. Additionally, they suggest that 63% of the star formation rate density occurs in massive [C ii]-bright systems and that ∼60–90% of [C ii] emitters at z ∼ 7 may be missed by bright UV selections. This highlights the importance of surveys focusing on especially massive, UV-faint sources at z > 6.
Authors: Thomas Herard-Demanche, Pascal A Oesch, Rychard Bouwens, Jacqueline A Hodge, Hiddo S B Algera, Manuel Aravena, Karin Cescon, Elisabete da Cunha, Pratika Dayal, Andrea Ferrara, Rebecca Fisher, Yoshinobu Fudamoto, Kasper E Heintz, Hanae Inami, Andrea Pallottini, Lucie E Rowland, Renske Smit, Laura Sommovigo, Mauro Stefanon, Michael W Topping, Paul van der Werf, Ivana F van Leeuwen
Institutions: Leiden University, Leiden Observatory, University of Geneva, University of Copenhagen, Institute of Astronomy and Astrophysics, Academia Sinica, Academia Sinica, Universidad Diego Portales, The University of Western Australia, ASTRO-3D, ARC Centre of Excellence for All-sky Astrophysics, International Centre for Radio Astronomy Research, University of Toronto, Canadian Institute for Theoretical Astrophysics, Scuola Normale Superiore, University of Manchester, Center for Frontier Science, Chiba University, Hiroshima University, Hiroshima Astrophysical Science Center, University of Pisa, Liverpool John Moores University, Flatiron Institute, Columbia University, Universitat de València, Instituto de Física de Cantabria, University of Arizona
Language: English
Subfield: Astronomy and Astrophysics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $3,046
Funders: National Science Foundation, Alexander von Humboldt-Stiftung, Aix-Marseille Université, National Radio Astronomy Observatory, European Commission, Schweizerischer Nationalfonds zur Förderung der Wissenschaftlichen Forschung, Rijksuniversiteit Groningen, Danmarks Grundforskningsfond, Academia Sinica, Nederlandse Organisatie voor Wetenschappelijk Onderzoek, Generalitat Valenciana, Korea Astronomy and Space Science Institute, National Astronomical Observatory of Japan, Agencia Nacional de Investigación y Desarrollo, Horizon 2020 Framework Programme, Science and Technology Facilities Council, Japan Society for the Promotion of Science, National Institutes of Natural Sciences, European Regional Development Fund, Agencia Estatal de Investigación
Awards: G1424166960, G2093941826, G2421315707, G3157600471, G3725028289, G457452161, G4781425868, MILLENIUM NUCLEUS FOR GALAXIES, G5376842035, G5850839165, G6033112984, G6347159581, 口腔粘膜の代謝について, Galaxy Build-up at Cosmic Dawn, A Revolutionary New Window on the First Galaxies, G7461836537, 古代説話における諸寺縁起の研究, Dissecting galaxies at the cosmic dawn, ORCHIDS: ORIGIN OF THE [CII] HALOS IN DISTANT SYSTEMS, CENTRO DE ASTROFISICA Y TECNOLOGIAS AFINES (CATA), G8784550270, G8999107647, G90960917
OpenAlex ID: W7223377586