Characterising the contribution of dust-obscured star formation at <i>z</i> ≳ 5 using 18 serendipitously identified [<scp>C ii</scp>] emitters
ABSTRACT We present a new method to determine the star formation rate density (SFRD) of the Universe at $z \gtrsim 5$ that includes the contribution of dust-obscured star formation. For this purpose, we use a [C ii] (158 $\mu$m) selected sample of galaxies serendipitously identified in the fields of known $z\gtrsim 4.5$ objects to characterise the fraction of obscured star formation rate (SFR). The advantage of a [C ii] selection is that our sample is SFR-selected, in contrast to an ultraviolet (UV)-selection that would be biased towards unobscured star formation. We obtain a sample of 23 [C ii] emitters near star-forming (SF) galaxies and quasi-stellar objects (QSOs) – three of which we identify for the first time – using previous literature and archival Atacama Large Millimeter/submillimeter Array data. 18 of these serendipitously identified galaxies have sufficiently deep rest-UV data and are used to characterise the obscured fraction of the star formation in galaxies with SFRs $\gtrsim 30\ \text{M}_{\odot } \ \text{yr}^{-1}$. We find that [C ii] emitters identified around SF galaxies have $\approx$63 per cent of their SFR obscured, while [C ii] emitters around QSOs have $\approx$93 per cent of their SFR obscured. By forward modelling existing wide-area UV luminosity function (LF) determinations, we derive the intrinsic UV LF using our characterisation of the obscured SFR. Integrating the intrinsic LF to $M_{\mathrm{ UV}}$ = $-$20, we find that the obscured SFRD contributes to $\gt 3~{{\ \rm per\ cent}}$ and $\gt 10~{{\ \rm per\ cent}}$ of the total SFRD at $z \sim 5$ and $z \sim 6$ based on our sample of companions galaxies near SF galaxies and QSOs, respectively. Our results suggest that dust obscuration is not negligible at $z\gtrsim 5$, further underlining the importance of far-infrared observations of the $z\gtrsim 5$ Universe.
Authors
- Pratika Dayal (ORCID: https://orcid.org/0000-0001-8460-1564)
- Raffaella Schneider (ORCID: https://orcid.org/0000-0001-9317-2888)
- Luca Graziani (ORCID: https://orcid.org/0000-0002-9231-1505)
- Fabian Walter (ORCID: https://orcid.org/0000-0003-4793-7880)
- Laia Barrufet (ORCID: https://orcid.org/0000-0003-1641-6185)
- A. P. S. Hygate (ORCID: https://orcid.org/0000-0002-6488-471X)
- Jacqueline Hodge (ORCID: https://orcid.org/0000-0001-6586-8845)
- Sander Schouws (ORCID: https://orcid.org/0000-0001-9746-0924)
- R. J. Bouwens (ORCID: https://orcid.org/0000-0002-4989-2471)
- Marco Palla (ORCID: https://orcid.org/0000-0002-3574-9578)
- Mauro Stefanon (ORCID: https://orcid.org/0000-0001-7768-5309)
- Hanae Inami (ORCID: https://orcid.org/0000-0003-4268-0393)
- Bram Venemans (ORCID: https://orcid.org/0000-0001-9024-8322)
- Andrea Ferrara (ORCID: https://orcid.org/0000-0002-9400-7312)
- Leindert Boogaard (ORCID: https://orcid.org/0000-0002-3952-8588)
- Lucie E. Rowland (ORCID: https://orcid.org/0009-0009-2671-4160)
- Hiddo Algera (ORCID: https://orcid.org/0000-0002-4205-9567)
- P. van der Werf
- R. A. A. Bowler (ORCID: https://orcid.org/0000-0003-3917-1678)
- Pascal A. Oesch (ORCID: https://orcid.org/0000-0001-5851-6649)
- Manuel Aravena (ORCID: https://orcid.org/0000-0002-6290-3198)
- Laura Sommovigo (ORCID: https://orcid.org/0000-0002-2906-2200)
- Roberto Decarli (ORCID: https://orcid.org/0000-0002-2662-8803)
Institutions
- Hiroshima University (JP)
- University of Geneva (CH)
- Leiden University (NL)
- University of Copenhagen (DK)
- Scuola Normale Superiore (IT)
- Universitat de València (ES)
- University of Groningen (NL)
- The University of Western Australia (AU)
- National Radio Astronomy Observatory (US)
- Astronomical Observatory of Rome (IT)
- University of Manchester (GB)
- Ghent University (BE)
- Royal Observatory (GB)
- Max Planck Institute for Astronomy (DE)
- Astronomical Institute of the Slovak Academy of Sciences (SK)
- Instituto de Física de Cantabria (ES)
- Istituto Nazionale di Fisica Nucleare, Sezione di Roma I (IT)
- National Astronomical Observatory of Japan (JP)
- International Centre for Radio Astronomy Research (AU)
- Osservatorio di Astrofisica e Scienza dello Spazio
- University of Chile (CL)
- Sapienza University of Rome (IT)
- Universidad Diego Portales (CL)
- University of Edinburgh (GB)
Publication Details
- Journal
- Monthly Notices of the Royal Astronomical Society
- Published
- 2024-09-19
- DOI
- https://doi.org/10.1093/mnras/stae2171
- Citations
- 5
- Primary Topic
- Galaxies: Formation, Evolution, Phenomena
- Type
- article
- Field-Weighted Citation Impact
- 1.66
Funders
- Technology Opportunities Program
- European Commission
- Rijksuniversiteit Groningen
- Nederlandse Organisatie voor Wetenschappelijk Onderzoek
- Ministero dell’Istruzione, dell’Università e della Ricerca
- National Astronomical Observatory of Japan
- Agencia Nacional de Investigación y Desarrollo
- Horizon 2020 Framework Programme
- Science and Technology Facilities Council
- Amaldi Research Center
- H2020 European Research Council