Tracing the evolutionary pathways of dust and cold gas in high-z quiescent galaxies with SIMBA

¹ National centre for Nuclear Research, Pasteura 7, 02-093 Warsaw, Poland
² SISSA, Via Bonomea 265, 34136 Trieste, Italy
³ Institute of Cosmology and Gravitation, University of Portsmouth, Burnaby Road, Portsmouth PO1 3FX, UK
⁴ INAF, OAPD, Vicolo dell’Osservatorio, 5, 35122 Padova, Italy
⁵ Department of Astronomy, University of Florida, 211 Bryant Space Sciences centre, Gainesville, FL, USA
⁶ Cosmic Dawn centre (DAWN), Copenhagen, Denmark
⁷ Institute for Astronomy, Royal Observatory, University of Edinburgh Edinburgh EH9 3HJ, UK
⁸ Department of Physics & Astronomy, University of the Western Cape, Robert Sobukwe Rd, Bellville 7535, South Africa
⁹ Department of Physics & Astronomy, University of British Columbia, 6224 Agricultural Road, Vancouver, BC V6T 1Z1, Canada
¹⁰ Department of Astronomy, University of Massachusetts, Amherst, MA 01003, USA
¹¹ INAF – Osservatorio astronomico d’Abruzzo, Via Maggini SNC, 64100 Teramo, Italy
¹² Department of Astronomy, University of Washington, Seattle WA 98195-1700, USA
¹³ Department of Astronomy, The University of Texas at Austin, 2515 Speedway Boulevard Stop C1400, Austin TX 78712, USA
¹⁴ DTU-Space, Technical University of Denmark, Elektrovej 327, 2800 Kgs. Lyngby, Denmark
¹⁵ Dipartimento di Fisica e Astronomia, Università di Padova, Vicolo dell’Osservatorio, 3, 35122 Padova, Italy
¹⁶ Max-Planck-Institute für Astrophysik, Karl-Schwarzschild-Strasse 1, 85740 Garching, Germany
¹⁷ Instituto de Astrofísica de Canarias, Vía Láctea S/N, E-38205 La Laguna, Spain
¹⁸ Departamento de Astrofísica, Universidad de La Laguna, E-38206 La Laguna, Spain

^⋆ Corresponding author; giuliano.lorenzon@ncbj.gov.pl

Received: 15 April 2024
Accepted: 28 May 2024

Abstract

Recent discoveries of copious amounts of dust in quiescent galaxies (QGs) at high redshifts (z ≳ 1 − 2) challenge the conventional view that these objects have a negligible interstellar medium (ISM) in proportion to their stellar mass. We made use of the SIMBA hydrodynamic cosmological simulation to explore how dust and cold gas evolve in QGs and are linked to the quenching processes affecting them. We applied a novel method for tracking the changes in the ISM dust abundance across the evolutionary history of QGs identified at 0 < z ≲ 2 in both cluster and field environments. The QGs transition from a diversity of quenching pathways, both rapidly and slowly, and they exhibit a wide range of times that elapsed between the quenching event and cold gas removal (from ∼650 Myr to ∼8 Gyr). Contrary to some claims, we find that quenching modes attributed to the feedback from active galactic nuclei (AGNs) do not affect dust and cold gas within the same timescales. Remarkably, QGs may replenish their dust content in the quenched phase primarily due to internal processes and marginally by external factors such as minor mergers. Prolonged grain growth on gas-phase metals appears to be the key mechanism for dust re-formation, which is effective within ∼100 Myr after the quenching event and rapidly increases the dust-to-gas mass ratio in QGs above the standard values (δ_DGR ≳ 1/100). Consequently, despite heavily depleted cold gas reservoirs, roughly half of QGs maintain little evolution of their ISM dust with stellar age within the first 2 Gyr following the quenching. Overall, we predict that relatively dusty QGs (M_dust/M_⋆ ≳ 10⁻³ − 10⁻⁴) arise from both fast and slow quenchers, and they are prevalent in quenched systems of intermediate and low stellar masses (9 < log(M_⋆/M_⊙) < 10.5). This strong prediction poses an immediate quest for observational synergy between, for example, the James Webb Space Telescope (JWST) and the Atacama Large Millimetre Array (ALMA).