Romain A. Meyer

Research & Teaching Fellow, University of Geneva

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Observatoire de Genève, University of Geneva

Chemin Pegasi 51

1290 Versoix, Switzerland

Welcome to my website! I am an astronomer and astrophysicist at the Observatory of Geneva, where I study early galaxy evolution. As a multi-wavelength observer, I use the largest telescopes on the ground and in space (VLT, Keck, ALMA, NOEMA, JWST, HST) to understand how the first galaxies formed, how their central supermassive black holes grow, and how the first sources of light reionised the Universe.

I obtained my PhD at University College London in 2020 (you can find my thesis here), followed by a first postdoc at the Max Planck Institute for Astronomy, Heidelberg. Since 2023 I have joined the University of Geneva and the observatory as a Research and Teaching Fellow. You can find my full CV here and my list of publications here.

My ongoing projects revolve mostly around cosmic hydrogen reionisation and its sources (VLT/JWST), and the gas reservoirs feeding early supermassive black holes (ALMA/NOEMA). I’m also very interested in machine-learning methods and simulation-based inference techniques which, I believe, are becoming more and more necessary to interpret the rich datasets we are getting from ALMA and JWST.

news

Oct 30, 2025 Finally remade my website after the JWST and ERC deadline!

selected publications

  1. JWST COSMOS-3D: Spectroscopic Census and Luminosity Function of [O III] Emitters at 6.75 < z < 9.05 in COSMOS
    Romain A. Meyer, Feige Wang, Koki Kakiichi, and 37 more authors
    arXiv e-prints, Oct 2025
  2. Probing patchy reionization with JWST: IGM opacity constraints from the Lyman α forest of galaxies in legacy extragalactic fields
    Romain A. Meyer, Guido Roberts-Borsani, Pascal A. Oesch, and 1 more author
    MNRAS, Sep 2025
  3. Pushing the Atacama Large Millimeter/submillimeter Array to the Limit: 140 pc Resolution Observations of a z = 6.6 Quasar–Galaxy Merger Resolve Strikingly Different Morphologies of Dust Continuum and [C II] 158 μm Emission
    Romain A. Meyer, Bram Venemans, Marcel Neeleman, and 2 more authors
    The Astrophysical Journal, Feb 2025
  4. JWST FRESCO: a comprehensive census of H β + [O III] emitters at 6.8 < z < 9.0 in the GOODS fields
    R. A. Meyer, P. A. Oesch, E. Giovinazzo, and 27 more authors
    MNRAS, Nov 2024
  5. Physical Constraints on the Extended Interstellar Medium of the z = 6.42 Quasar J1148+5251: [C II]_158 μm, [N II]_205 μm, and [O I]_146 μm Observations
    Romain A. Meyer, Fabian Walter, Claudia Cicone, and 7 more authors
    The Astrophysical Journal, Mar 2022
  6. The role of galaxies and AGN in reionizing the IGM - III. IGM-galaxy cross-correlations at z ∼ 6 from eight quasar fields with DEIMOS and MUSE
    Romain A. Meyer, Koki Kakiichi, Sarah E. I. Bosman, and 6 more authors
    MNRAS, May 2020
  7. New constraints on quasar evolution: broad-line velocity shifts over 1.5 ≲ z ≲ 7.5
    Romain A. Meyer, Sarah E. I. Bosman, and Richard S. Ellis
    MNRAS, Aug 2019
  8. The role of galaxies and AGNs in reionizing the IGM - II. Metal-tracing the faint sources of reionization at 5 ≲ z ≲ 6
    Romain A. Meyer, Sarah E. I. Bosman, Koki Kakiichi, and 1 more author
    MNRAS, Feb 2019