NOEMA^3D: A first kiloparsec resolution study of a z ∼ 1.5 main sequence barred galaxy channeling gas into a growing bulge

¹ Max-Planck-Institut für Extraterrestrische Physik (MPE), Gießenbachstr. 1, D-85748 Garching, Germany
² Max-Planck-Institut für Astrophysik (MPA), Karl-Schwarzschild-Str. 1, D-85748 Garching, Germany
³ Departments of Physics and Astronomy, University of California, Berkeley, CA 94720, USA
⁴ Institut de Radioastronomie Millimétrique (IRAM), 300 Rue de la Piscine, 38400 Saint-Martin-d’Hères, France
⁵ Universitäts-Sternwarte Ludwig-Maximilians-Universität (USM), Scheinerstr. 1, München D-81679, Germany
⁶ Observatoire de Paris, LERMA, CNRS, PSL Univ., Sorbonne University, UPMC, Paris, France
⁷ College de France, 11 Pl. Marcelin Berthelot, 75231 Paris, France
⁸ Technical University of Munich, TUM School of Natural Sciences, Physics Department, 85747 Garching, Germany
⁹ Observatorio Astronómico Nacional (OAN-IGN)-Observatorio de Madrid, Alfonso XII, 3, 28014 Madrid, Spain
¹⁰ Departamento de Astronomía, Universidad de Concepción, Barrio Universitario, Concepción, Chile
¹¹ Millenium Nucleus for Galaxies (MINGAL), Concepción, Chile
¹² Cosmic Dawn Center (DAWN), Copenhagen, Denmark
¹³ DTU-Space, Technical University of Denmark, Elektrovej 327, DK2800 Kgs. Lyngby, Denmark
¹⁴ Purple Mountain Observatory, Chinese Academy of Sciences, 10 Yuanhua Road, Nanjing 210023, China
¹⁵ School of Physics and Astronomy, Tel Aviv University, Tel Aviv, 69978 Israel
¹⁶ Scuola Normale Superiore, Piazza dei Cavalieri 7, I-56126 Pisa, Italy
¹⁷ Department of Physics and Astronomy and PITT PACC, University of Pittsburgh, Pittsburgh, PA 15260, USA
¹⁸ Osservatorio Astronomico di Padova, Vicolo dell’Osservatorio 5, Padova I-35122, Italy
¹⁹ Department of Physics and Astronomy “Augusto Righi”, University of Bologna, Via Piero Gobetti 93/2, 40129 Bologna, Italy
²⁰ INAF – Astrophysics and Space Science Observatory of Bologna, Via Piero Gobetti 93/3, 40129 Bologna, Italy
²¹ Centre for Computational Astrophysics, Flatiron Institute, 162 5th Avenue, New York, NY 10010, USA
²² Department of Physics, University of Bath, Claverton Down, Bath BA2 7AY, UK

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Received: 7 May 2025
Accepted: 5 September 2025

Abstract

We present a very deep CO(3–2) observation of a massive, gas-rich, main sequence, barred spiral galaxy at z ≈ 1.52. Our data were taken with the IRAM-NOEMA interferometer for a 12-antenna equivalent on-source integration time of ∼50 hours. We fit the major axis kinematics with the forward modeling of a rotating disk and subtracted the two-dimensional beam convolved best-fit model, which revealed signatures of planar noncircular motions in the residuals. The inferred in-plane radial velocities are remarkably high, of the order of ≈60 km/s. Direct comparisons with a high-resolution, simulated, gas-rich, barred galaxy, obtained with the moving mesh code AREPO and the TNG sub-grid model, show that the observed noncircular gas flows can be explained as radial flows driven by the central bar, with an inferred net inflow rate of the order of the star formation rate (SFR). Given the recent evidence for a higher-than-expected fraction of barred disk galaxies at cosmic noon, our results suggest that rapid gas inflows due to bars could be important evolutionary drivers for the dominant population of star-forming galaxies at the peak epoch of star and galaxy formation.