Simulating nearby disc galaxies on the main star formation sequence

I. Bar formation and the building of the central gas reservoir

¹ Excellence Cluster ORIGINS, Boltzmannstraße 2, 85748 Garching, Germany
² European Southern Observatory, Karl-Schwarzschild-Straße 2, 85748 Garching, Germany
e-mail: pierrick.verwilghen@eso.org
³ Univ. Lyon, Univ. Lyon1, ENS de Lyon, CNRS, Centre de Recherche Astrophysique de Lyon UMR5574, 69230 Saint-Genis-Laval, France
⁴ Observatoire Astronomique de Strasbourg, Université de Strasbourg, CNRS UMR 7550, 67000 Strasbourg, France
⁵ University of Strasbourg Institute for Advanced Study, 5 Allée du Général Rouvillois, 67083 Strasbourg, France
⁶ Astronomy Unit, Department of Physics, University of Trieste, Via Tiepolo 11, 34131 Trieste, Italy
⁷ INAF – Osservatorio Astronomico di Trieste, Via Tiepolo 11, 34131 Trieste, Italy
⁸ ICSC – Italian Research Center on High Performance Computing, Big Data and Quantum Computing, Italy
⁹ Department of Astrophysical Sciences, Princeton University, 4 Ivy Lane, Princeton, NJ 08544, USA
¹⁰ Center for Astrophysics, Harvard & Smithsonian, 60 Garden Street, Cambridge, MA, USA
¹¹ Universität Heidelberg, Zentrum für Astronomie, Institut für Theoretische Astrophysik, Albert-Ueberle-Str. 2, 69120 Heidelberg, Germany
¹² Universität Heidelberg, Interdisziplinäres Zentrum für Wissenschaftliches Rechnen, Im Neuenheimer Feld 205, 69120 Heidelberg, Germany
¹³ Università dell’Insubria, Via Valleggio 11, 22100 Como, Italy
¹⁴ Department of Physics, University of Surrey, Guildford GU2 7XH, UK
¹⁵ Universitäts-Sternwarte, Fakultät für Physik, Ludwig-Maximilians-Universität München, Scheinerstr. 1, 81679 München, Germany
¹⁶ Max-Planck-Institut für Astrophysik, Karl-Schwarzschild-Straße 1, 85741 Garching, Germany
¹⁷ Research School of Astronomy and Astrophysics, Australian National University, Canberra, ACT 2611, Australia
¹⁸ ARC Centre of Excellence for All Sky Astrophysics in 3 Dimensions (ASTRO 3D), Australia
¹⁹ Sub-department of Astrophysics, Department of Physics, University of Oxford, Keble Road, Oxford OX1 3RH, UK
²⁰ Sterrenkundig Observatorium, Universiteit Gent, Krijgslaan 281 S9, 9000 Gent, Belgium
²¹ Max Planck Institut für Astronomie, Königstuhl 17, 69117 Heidelberg, Germany
²² Observatorio Astronómico Nacional (IGN), C/Alfonso XII 3, Madrid 28014, Spain

Received: 28 November 2023
Accepted: 10 April 2024

Abstract

Past studies have long emphasised the key role played by galactic stellar bars in the context of disc secular evolution, via the redistribution of gas and stars, the triggering of star formation, and the formation of prominent structures such as rings and central mass concentrations. However, the exact physical processes acting on those structures, as well as the timescales associated with the building and consumption of central gas reservoirs are still not well understood. We are building a suite of hydro-dynamical RAMSES simulations of isolated, low-redshift galaxies that mimic the properties of the PHANGS sample. The initial conditions of the models reproduce the observed stellar mass, disc scale length, or gas fraction, and this paper presents a first subset of these models. Most of our simulated galaxies develop a prominent bar structure, which itself triggers central gas fuelling and the building of an over-density with a typical scale of 100−1000 pc. We confirm that if the host galaxy features an ellipsoidal component, the formation of the bar and gas fuelling are delayed. We show that most of our simulations follow a common time evolution, when accounting for mass scaling and the bar formation time. In our simulations, the stellar mass of 10¹⁰ M_⊙ seems to mark a change in the phases describing the time evolution of the bar and its impact on the interstellar medium. In massive discs (M_⋆ ≥ 10¹⁰ M_⊙), we observe the formation of a central gas reservoir with star formation mostly occurring within a restricted starburst region, leading to a gas depletion phase. Lower-mass systems (M_⋆ < 10¹⁰ M_⊙) do not exhibit such a depletion phase, and show a more homogeneous spread of star-forming regions along the bar structure, and do not appear to host inner bar-driven discs or rings. Our results seem to be supported by observations, and we briefly discuss how this new suite of simulations can help our understanding of the secular evolution of main sequence disc galaxies.