{"keyword":["Space and Planetary Science","Astronomy and Astrophysics"],"date_published":"2021-07-20T00:00:00Z","year":"2021","publisher":"IOP Publishing","article_type":"original","day":"20","intvolume":"       916","language":[{"iso":"eng"}],"issue":"1","oa_version":"Preprint","main_file_link":[{"open_access":"1","url":"https://arxiv.org/abs/2105.12489"}],"scopus_import":"1","quality_controlled":"1","title":"Measuring the average molecular gas content of star-forming galaxies at z = 3–4","citation":{"mla":"Boogaard, Leindert A., et al. “Measuring the Average Molecular Gas Content of Star-Forming Galaxies at z = 3–4.” <i>The Astrophysical Journal</i>, vol. 916, no. 1, 12, IOP Publishing, 2021, doi:<a href=\"https://doi.org/10.3847/1538-4357/ac01d7\">10.3847/1538-4357/ac01d7</a>.","ama":"Boogaard LA, Bouwens RJ, Riechers D, et al. Measuring the average molecular gas content of star-forming galaxies at z = 3–4. <i>The Astrophysical Journal</i>. 2021;916(1). doi:<a href=\"https://doi.org/10.3847/1538-4357/ac01d7\">10.3847/1538-4357/ac01d7</a>","short":"L.A. Boogaard, R.J. Bouwens, D. Riechers, P. van der Werf, R. Bacon, J.J. Matthee, M. Stefanon, A. Feltre, M. Maseda, H. Inami, M. Aravena, J. Brinchmann, C. Carilli, T. Contini, R. Decarli, J. González-López, T. Nanayakkara, F. Walter, The Astrophysical Journal 916 (2021).","ieee":"L. A. Boogaard <i>et al.</i>, “Measuring the average molecular gas content of star-forming galaxies at z = 3–4,” <i>The Astrophysical Journal</i>, vol. 916, no. 1. IOP Publishing, 2021.","ista":"Boogaard LA, Bouwens RJ, Riechers D, van der Werf P, Bacon R, Matthee JJ, Stefanon M, Feltre A, Maseda M, Inami H, Aravena M, Brinchmann J, Carilli C, Contini T, Decarli R, González-López J, Nanayakkara T, Walter F. 2021. Measuring the average molecular gas content of star-forming galaxies at z = 3–4. The Astrophysical Journal. 916(1), 12.","chicago":"Boogaard, Leindert A., Rychard J. Bouwens, Dominik Riechers, Paul van der Werf, Roland Bacon, Jorryt J Matthee, Mauro Stefanon, et al. “Measuring the Average Molecular Gas Content of Star-Forming Galaxies at z = 3–4.” <i>The Astrophysical Journal</i>. IOP Publishing, 2021. <a href=\"https://doi.org/10.3847/1538-4357/ac01d7\">https://doi.org/10.3847/1538-4357/ac01d7</a>.","apa":"Boogaard, L. A., Bouwens, R. J., Riechers, D., van der Werf, P., Bacon, R., Matthee, J. J., … Walter, F. (2021). Measuring the average molecular gas content of star-forming galaxies at z = 3–4. <i>The Astrophysical Journal</i>. IOP Publishing. <a href=\"https://doi.org/10.3847/1538-4357/ac01d7\">https://doi.org/10.3847/1538-4357/ac01d7</a>"},"month":"07","date_created":"2022-07-06T13:05:50Z","acknowledgement":"We would like to thank the referee for a constructive and helpful report. L.A.B. is grateful to Corentin Schreiber for assisting with the near-infrared spectroscopy during the early stages of this work. L.A.B. acknowledges support from the Leids Kerkhoven-Bosscha Fonds under subsidy numbers 18.2.074 and 19.1.147. D.R. acknowledges support from the National Science Foundation under grant numbers AST-1614213 and AST-1910107. D.R. also acknowledges support from the Alexander von Humboldt Foundation through a Humboldt Research Fellowship for Experienced Researchers. A.F. acknowledges the support from grant PRIN MIUR 201720173ML3WW_001. J.B. acknowledges support by Fundação para a Ciência e a Tecnologia (FCT) through the research grants UID/FIS/04434/2019, UIDB/04434/2020, UIDP/04434/2020. H.I. acknowledges support from JSPS KAKENHI grant No. JP19K23462. This work is based on observations collected at the European Southern Observatory under ESO programs 094.A-2089(B), 095.A-0010(A), 096.A-0045(A), 096.A-0045(B), 099.A-0858(A), and 0101.A-0725(A). This paper makes use of the following ALMA data: ADS/JAO.ALMA#2016.1.00324.L. ALMA is a partnership of ESO (representing its member states), NSF (USA), and NINS (Japan), together with NRC (Canada), NSC 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. The National Radio Astronomy Observatory is a facility of the National Science Foundation operated under cooperative agreement by Associated Universities, Inc. This work was supported by a NASA Keck PI Data Award, administered by the NASA Exoplanet Science Institute. Data presented herein were obtained at the W. M. Keck Observatory from telescope time allocated to the National Aeronautics and Space Administration through the agency's scientific partnership with the California Institute of Technology and the University of California. The Observatory was made possible by the generous financial support of the W. M. Keck Foundation. The authors wish to recognize and acknowledge the very significant cultural role and reverence that the summit of Maunakea has always had within the indigenous Hawaiian community. We are most fortunate to have the opportunity to conduct observations from this mountain.","article_processing_charge":"No","user_id":"2DF688A6-F248-11E8-B48F-1D18A9856A87","oa":1,"status":"public","external_id":{"arxiv":["2105.12489"]},"publication_identifier":{"issn":["0004-637X"],"eissn":["1538-4357"]},"date_updated":"2022-07-19T09:32:48Z","volume":916,"extern":"1","type":"journal_article","publication_status":"published","publication":"The Astrophysical Journal","abstract":[{"text":"We study the molecular gas content of 24 star-forming galaxies at z = 3–4, with a median stellar mass of 109.1 M⊙, from the MUSE Hubble Ultra Deep Field (HUDF) Survey. Selected by their Lyα λ1216 emission and HF160W-band magnitude, the galaxies show an average $\\langle {\\mathrm{EW}}_{\\mathrm{Ly}\\alpha }^{0}\\rangle \\approx 20$ Å, below the typical selection threshold for Lyα emitters (${\\mathrm{EW}}_{\\mathrm{Ly}\\alpha }^{0}\\gt 25$ Å), and a rest-frame UV spectrum similar to Lyman-break galaxies. We use rest-frame optical spectroscopy from KMOS and MOSFIRE, and the UV features observed with MUSE, to determine the systemic redshifts, which are offset from Lyα by 〈Δv(Lyα)〉 = 346 km s−1, with a 100 to 600 km s−1 range. Stacking 12CO J = 4 → 3 and [C i]3P1 → 3P0 (and higher-J CO lines) from the ALMA Spectroscopic Survey of the HUDF, we determine 3σ upper limits on the line luminosities of 4.0 × 108 K km s−1pc2 and 5.6 × 108 K km s−1pc2, respectively (for a 300 km s−1 line width). Stacking the 1.2 mm and 3 mm dust-continuum flux densities, we find a 3σ upper limits of 9 μJy and 1.2 μJy, respectively. The inferred gas fractions, under the assumption of a \"Galactic\" CO-to-H2 conversion factor and gas-to-dust ratio, are in tension with previously determined scaling relations. This implies a substantially higher αCO ≥ 10 and δGDR ≥ 1200, consistent with the subsolar metallicity estimated for these galaxies ($12+\\mathrm{log}({\\rm{O}}/{\\rm{H}})\\approx 7.8\\pm 0.2$). The low metallicity of z ≥ 3 star-forming galaxies may thus make it very challenging to unveil their cold gas through CO or dust emission, warranting further exploration of alternative tracers, such as [C ii].","lang":"eng"}],"article_number":"12","_id":"11512","doi":"10.3847/1538-4357/ac01d7","author":[{"full_name":"Boogaard, Leindert A.","first_name":"Leindert A.","last_name":"Boogaard"},{"first_name":"Rychard J.","full_name":"Bouwens, Rychard J.","last_name":"Bouwens"},{"first_name":"Dominik","full_name":"Riechers, Dominik","last_name":"Riechers"},{"last_name":"van der Werf","full_name":"van der Werf, Paul","first_name":"Paul"},{"last_name":"Bacon","full_name":"Bacon, Roland","first_name":"Roland"},{"first_name":"Jorryt J","full_name":"Matthee, Jorryt J","orcid":"0000-0003-2871-127X","last_name":"Matthee","id":"7439a258-f3c0-11ec-9501-9df22fe06720"},{"last_name":"Stefanon","full_name":"Stefanon, Mauro","first_name":"Mauro"},{"last_name":"Feltre","full_name":"Feltre, Anna","first_name":"Anna"},{"first_name":"Michael","full_name":"Maseda, Michael","last_name":"Maseda"},{"last_name":"Inami","full_name":"Inami, Hanae","first_name":"Hanae"},{"full_name":"Aravena, Manuel","first_name":"Manuel","last_name":"Aravena"},{"full_name":"Brinchmann, Jarle","first_name":"Jarle","last_name":"Brinchmann"},{"first_name":"Chris","full_name":"Carilli, Chris","last_name":"Carilli"},{"last_name":"Contini","first_name":"Thierry","full_name":"Contini, Thierry"},{"last_name":"Decarli","first_name":"Roberto","full_name":"Decarli, Roberto"},{"full_name":"González-López, Jorge","first_name":"Jorge","last_name":"González-López"},{"last_name":"Nanayakkara","first_name":"Themiya","full_name":"Nanayakkara, Themiya"},{"first_name":"Fabian","full_name":"Walter, Fabian","last_name":"Walter"}]}