Atacama Large Aperture Submillimeter Telescope (AtLAST) Science: The hidden circumgalactic medium

• DOI: 10.48550/arxiv.2403.00924
• Publication Date: 2024-03-01
• Authors: Minju Lee; Alice Schimek; C. Cicone; P. Andreani; Gergö Popping; Laura Sommovigo; P. N. Appleton; M. Bischetti; Sebastiano Cantalupo; Chian-Chou Chen; H. Dannerbauer; C. De Breuck; Luca Di Mascolo; Bjorn Emonts; E. Hatziminaoglou; Antonio Pensabene; Francesca Rizzo; Matus Rybak; Sijing Shen; A. Lundgren; Mark Booth; Pamela Klaassen; Tony Mroczkowski; Martin Cordiner; Doug Johnstone; E. van Kampen; Daizhong Liu; Thomas J. Maccarone; A. Saintonge; M. W. L. Smith; Alexander E. Thelen; Sven Wedemeyer
• Keywords: Aperture (computer memory)

Our knowledge of galaxy formation and evolution has incredibly progressed through multi-wavelength observational constraints the interstellar medium (ISM) galaxies at all cosmic epochs. However, little is known about physical properties more diffuse lower surface brightness reservoir gas dust that extends beyond ISM scales fills dark matter haloes up to their virial radii, circumgalactic (CGM). New theoretical studies increasingly stress relevance latter for understanding feedback feeding mechanisms shape across times, whose cumulative effects leave clear imprints into CGM. Recent are showing a -- so far unconstrained fraction CGM mass may reside in cold (T < 1e4 K) molecular atomic phase, especially high-redshift dense environments. These phases, together with warmer ionised can be studied from z ~ 0 10 bright far-infrared sub-millimeter emission lines such as [C II] 158${\mu}$m, [O III] 88 ${\mu}$m, I] 609${\mu}$m, 370${\mu}$m, rotational transitions CO. Imaging hidden lead breakthrough but requires new facility specifications proposed Atacama Large Aperture Submillimeter Telescope (AtLAST). In this paper, we use empirical arguments motivate future ambitious observations AtLAST describe technical requirements needed telescope its instrumentation perform science.