Atacama Large Aperture Submillimeter Telescope (AtLAST) science: Our Galaxy

Open Res Eur. 2025 Feb 10:4:112. doi: 10.12688/openreseurope.17450.1. eCollection 2024.

Abstract

As we learn more about the multi-scale interstellar medium (ISM) of our Galaxy, we develop a greater understanding for the complex relationships between the large-scale diffuse gas and dust in Giant Molecular Clouds (GMCs), how it moves, how it is affected by the nearby massive stars, and which portions of those GMCs eventually collapse into star forming regions. The complex interactions of those gas, dust and stellar populations form what has come to be known as the ecology of our Galaxy. Because we are deeply embedded in the plane of our Galaxy, it takes up a significant fraction of the sky, with complex dust lanes scattered throughout the optically recognizable bands of the Milky Way. These bands become bright at (sub-)millimetre wavelengths, where we can study dust thermal emission and the chemical and kinematic signatures of the gas. To properly study such large-scale environments, requires deep, large area surveys that are not possible with current facilities. Moreover, where stars form, so too do planetary systems, growing from the dust and gas in circumstellar discs, to planets and planetesimal belts. Understanding the evolution of these belts requires deep imaging capable of studying belts around young stellar objects to Kuiper belt analogues around the nearest stars. Here we present a plan for observing the Galactic Plane and circumstellar environments to quantify the physical structure, the magnetic fields, the dynamics, chemistry, star formation, and planetary system evolution of the galaxy in which we live with AtLAST; a concept for a new, 50m single-dish sub-mm telescope with a large field of view which is the only type of facility that will allow us to observe our Galaxy deeply and widely enough to make a leap forward in our understanding of our local ecology.

Keywords: Astronomical instrumentation methods and techniques; Submillimeter ISM; Submillimeter Magnetic fields; Submillimeter Surveys; Submillimeter planetary systems; Telescopes; The Galaxy; solar neighborhood.

Grants and funding

This project has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No [951815] (Towards an Atacama Large Aperture Submillimeter Telescope [AtLAST]). K.P. is a Royal Society University Research Fellow, supported by grant number URF\R1\211322. S.M. is supported by a Royal Society University Research Fellowship (URF-R1-221669) J.B.L. acknowledges the Smithsonian Institute for funding via a Submillimeter Array (SMA) Fellowship. L.D.M. acknowledges support by the French government, through the UCAJ.E.D.I. Investments in the Future project managed by the National Research Agency (ANR) with the reference number ANR-15-IDEX-01. M.L. acknowledges support from the European Union’s Horizon Europe research and innovation programme under the Marie Skłodowska-Curie grant agreement No 101107795 (ECOology for Galaxies using ALMA archive and Legacy surveys [ECOGAL]. S.W. acknowledges support by the Research Council of Norway through the EMISSA project (project number 286853) and the Centres of Excellence scheme, project number 262622 (“Rosseland Centre for Solar Physics”).