Year: 2026
Type: preprint
Abstract: Understanding how supermassive black holes (SMBHs) grow and regulate the growth of their host galaxies requires tracing the cold molecular interstellar medium (ISM) throughout the full AGN feeding-feedback cycle. Molecular gas constitutes both the primary fuel for star formation and black-hole accretion and one of the ISM phases most directly affected by AGN-driven radiation, winds, and radio jets. Over the past decade, ALMA has resolved circumnuclear molecular discs, rings, spirals, tori, and jet-driven outflows on scales of tens of parsecs in nearby AGN. These studies have demonstrated that combining spatially resolved gas kinematics with multi-line diagnostics is essential for disentangling the physical processes underlying the observed gas conditions. However, our current picture remains largely based on a limited number of exceptionally nearby systems. Most local AGN have instead been observed with ALMA in a single transition at moderate or low angular resolution, preventing a systematic characterisation of both the dynamics and physical state of the gas. Moreover, existing studies have largely overlooked kinetic-mode AGN hosted by massive early-type galaxies, despite their central importance for understanding maintenance-mode feedback. In this White Paper, we argue that ALMA2040 should transform these detailed case studies into a statistical framework. A $\sim10\times$ improvement in line sensitivity relative to the current ALMA, together with fast mosaicking, ultra-wide instantaneous bandwidth, and longer baselines (resolving up to $\sim9$ mas at 230 GHz), will enable homogeneous, multi-line mapping of the molecular ISM on giant molecular clouds scales across statistically significant samples of both radiative- and kinetic-mode AGN out to $z\lesssim0.1$.
Source: arXiv (Cornell University)
Authors: Ruffa, Ilaria, Salvestrini, Francesco, Herrero, Almudena Alonso, Audibert, Anelise, Bertola, Elena, Casasola, Viviana, Decarli, Roberto, Espada, Daniel, Maio, Umberto, Nguyen, Dieu D., Pandey-Pommier, Mamta, Pereira-Santaella, Miguel, Pozzi, Francesca, Prathap, Jahang, Thater, Sabine, Zanchettin, Maria Vittoria
Institutions: Arcetri Astrophysical Observatory, Istituto di Radioastronomia di Bologna, National Institute for Astrophysics, Trieste Astronomical Observatory, Institute for Fundamental Physics of the Universe, Centro de Astrobiología, Universidad de La Laguna, Instituto de Astrofísica de Canarias, Osservatorio di Astrofisica e Scienza dello Spazio, Universidad de Granada, University of Michigan, Université catholique de lyon, Instituto de Física Fundamental, University of Bologna, Macquarie University, University of Vienna, Institute for Space Astrophysics and Planetology
Language: English
Subfield: Astronomy and Astrophysics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W7222941779