Issue |
A&A
Volume 649, May 2021
|
|
---|---|---|
Article Number | A152 | |
Number of page(s) | 18 | |
Section | Extragalactic astronomy | |
DOI | https://doi.org/10.1051/0004-6361/202038944 | |
Published online | 01 June 2021 |
The ALPINE-ALMA [CII] survey
Obscured star formation rate density and main sequence of star-forming galaxies at z > 4
1
Max-Planck-Institut für Astronomie, Königstuhl 17, 69117 Heidelberg, Germany
e-mail: khusanova@mpia.de
2
Aix Marseille Université, CNRS, LAM (Laboratoire d’Astrophysique de Marseille) UMR 7326, 13388 Marseille, France
3
IPAC, California Institute of Technology, MC 314-6, 1200 E. California Blvd., Pasadena, CA 91125, USA
4
Cosmic Dawn Center (DAWN), Copenhagen, Denmark
5
Observatoire de Genève, Université de Genève, 51 Ch. des Maillettes, 1290 Versoix, Switzerland
6
Kavli Institute for the Physics and Mathematics of the Universe, The University of Tokyo, 277-8583 Kashiwa, Japan
7
Department of Astronomy, School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo, Tokyo 113-0033, Japan
8
Dipartimento di Fisica e Astronomia, Università di Padova, Vicolo dell’Osservatorio 3, 35122 Padova, Italy
9
Caltech Optical Observatories, California Institute of Technology, Pasadena, CA 91125, USA
10
Università di Bologna, Dipartimento di Fisica e Astronomia, Via Gobetti 93/2, 40129 Bologna, Italy
11
Istituto Nazionale di Astrofisica: Osservatorio di Astrofisica e Scienza dello Spazio di Bologna, Via Gobetti 93/3, 40129 Bologna, Italy
12
Instituto de Investigación Multidisciplinar en Ciencia y Tecnología, Universidad de La Serena, Raúl Bitrán 1305, La Serena, Chile
13
Departamento de Astronomía, Universidad de La Serena, Av. Juan Cisternas 1200 Norte, La Serena, Chile
14
Centro de Astronomía (CITEVA), Universidad de Antofagasta, Avenida Angamos 601, Antofagasta, Chile
15
INAF – Osservatorio Astrofisico di Arcetri, Largo E. Fermi 5, 50125 Firenze, Italy
16
Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218, USA
17
Cavendish Laboratory, University of Cambridge, 19 J. J. Thomson Ave., Cambridge CB3 0HE, UK
18
Kavli Institute for Cosmology, University of Cambridge, Madingley Road, Cambridge CB3 0HA, UK
19
Department of Physics and Astronomy, University College London, Gower Street, London WC1E 6BT, UK
20
Department of Physics and Astronomy, University of California, Davis, One Shields Ave., Davis, CA 95616, USA
21
Department of Astronomy, Cornell University, Space Sciences Building, Ithaca, NY 14853, USA
22
INAF-Osservatorio Astronomico di Padova, Vicolo dell’Osservatorio 5, 35122 Padova, Italy
23
Niels Bohr Institute, University of Copenhagen, Lyngbyvej 2, 2100 Copenhagen, Denmark
Received:
16
July
2020
Accepted:
1
February
2021
Star formation rate (SFR) measurements at z > 4 have relied mostly on the rest-frame far-ultraviolet (FUV) observations. The corrections for dust attenuation based on the IRX-β relation are highly uncertain and are still debated in the literature. Hence, rest-frame far-infrared (FIR) observations are necessary to constrain the dust-obscured component of the SFR. In this paper, we exploit the rest-frame FIR continuum observations collected by the ALMA Large Program to INvestigate [CII] at Early times (ALPINE) to directly constrain the obscured SFR in galaxies at 4.4 < z < 5.9. We used stacks of continuum images to measure average infrared luminosities taking both detected and undetected sources into account. Based on these measurements, we measured the position of the main sequence of star-forming galaxies and the specific SFR (sSFR) at z ∼ 4.5 and z ∼ 5.5. We find that the main sequence and sSFR do not significantly evolve between z ∼ 4.5 and z ∼ 5.5, as opposed to lower redshifts. We developed a method to derive the obscured SFR density (SFRD) using the stellar masses or FUV-magnitudes as a proxy of FIR fluxes measured on the stacks and combining them with the galaxy stellar mass functions and FUV luminosity functions from the literature. We obtain consistent results independent of the chosen proxy. We find that the obscured fraction of SFRD is decreasing with increasing redshift, but even at z ∼ 5.5 it constitutes around 61% of the total SFRD.
Key words: galaxies: high-redshift / galaxies: evolution / galaxies: star formation / submillimeter: galaxies
© Y. Khusanova et al. 2021
Open Access article, published by EDP Sciences, under the terms of the Creative Commons Attribution License (https://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Open Access funding provided by Max Planck Society.
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