MNRAS 000, 1–25 (2020) Preprint 5 March 2020 Compiled using MNRAS L A T E X style file v3.0 S2COSMOS: Evolution of Gas Mass with Redshift Using Dust Emission Jenifer S. Millard 1 ? , Stephen A. Eales 1 , M.W.L. Smith 1 , H.L. Gomez 1 , K. Malek 2 ,3 , J.M. Simpson 4 , Y. Peng 5 , M. Sawicki 6 , R. A. Beeston 1 , Andrew Bunker 7 , Y. Ao 8 , A. Babul 9 , L.C. Ho 5 ,10 , Ho Seong Hwang 11 , M. J. Michalowski 12 , N. Scoville 13 , H. Shim 14 , Y. Toba 15 ,16 ,17 1 School of Physics and Astronomy, Cardiff University, The Parade, Cardiff, CF24 3AA, UK 2 Aix Marseille Univ. CNRS, CNES, LAM, Marseille, France 3 National Centre for Nuclear Research, ul. Hoza 69, 00-681 Warszawa, Poland 4 EACOA fellow: Academia Sinica Institute of Astronomy and Astrophysics, No. 1, Sec. 4, Roosevelt Rd., Taipei 10617, Taiwan 5 The Kavli Institute for Astronomy and Astrophysics, Peking University, 5 Yiheyuan Road, Haidian District, Beijing 100871, PR China 6 Institute for Computational Astrophysics and Department of Astronomy and Physics, Saint Mary’s University, Halifax, Nova Scotia, B3H 3C3, Canada 7 Sub-dept. of Astrophysics, Department of Physics, University of Oxford, Denys Wilkinson Building, Keble Road, Oxford OX1 3RH, UK 8 Purple Mountain Observatory and Key Laboratory for Radio Astronomy, Chinese Academy of Sciences, 8 Yuanhua Road, Nanjing 210034, PR China 9 Department of Physics and Astronomy, University of Victoria, 3800 Finnerty Road, Victoria V8P 1A1, Canada 10 Department of Astronomy, School of Physics, Peking University, 5 Yiheyuan Road, Haidian District, Beijing 100871, PR China 11 Korea Astronomy and Space Science Institute, 776 Daedeokdae-ro, Yuseong-gu, Daejeon 34055, Republic of Korea 12 Astronomical Observatory Institute, Faculty of Physics, Adam Mickiewicz University, ul. Sloneczna 36, 60-286, Pozna´ n, Poland 13 California Institute of Technology, MC 249-17, 1200 East California Boulevard, Pasadena, CA 91125, USA 14 Department of Earth Science Education, Kyungpook National University, 80 Daehak-ro, Buk-gu, Daegu 41566, Republic of Korea 15 Department of Astronomy, Kyoto University, Kitashirakawa-Oiwake-cho, Sakyo-ku, Kyoto 606-8502, Japan 16 Academia Sinica Institute of Astronomy and Astrophysics, No. 1, Sec. 4, Roosevelt Rd., Taipei 10617, Taiwan 17 Research Center for Space and Cosmic Evolution, Ehime University, 2-5 Bunkyo-cho, Matsuyama, Ehime 790-8577, Japan Accepted 2020 March 2. Received 2019 October 10; in original form ZZZ ABSTRACT We investigate the evolution of the gas mass fraction for galaxies in the COSMOS field using submillimetre emission from dust at 850 μm. We use stacking methodologies on the 850 μm S2COSMOS map to derive the gas mass fraction of galaxies out to high redshifts, 0 ≤ z ≤ 5, for galaxies with stellar masses of 10 9.5 < M * (M  ) < 10 11.75 . In comparison to previous literature studies we extend to higher redshifts, include more normal star-forming galaxies (on the main sequence), and also investigate the evolution of the gas mass fraction split by star-forming and passive galaxy populations. We find our stacking results broadly agree with scaling relations in the literature. We find tentative evidence for a peak in the gas mass fraction of galaxies at around z ∼ 2.5 - 3, just before the peak of the star formation history of the Universe. We find that passive galaxies are particularly devoid of gas, compared to the star-forming population. We find that even at high redshifts, high stellar mass galaxies still contain significant amounts of gas. Key words: galaxies:evolution – galaxies:ISM – submillimetre:ISM – galax- ies:statistics ? E-mail: jenifer.millard@astro.cf.ac.uk 1 INTRODUCTION Some of the biggest questions facing astronomy today are in- spired by galaxies; specifically, we desire to know the origin and content of these complex structures, and how their con- © 2020 The Authors arXiv:2003.01727v1 [astro-ph.GA] 3 Mar 2020