ALMA2040: The High-Redshift Circumgalactic Medium. Imaging the fueling and feedback of galaxies in the early universe
The authors propose three scientific goals for an ALMA2040 telescope: imaging extended cool gas halos around Milky Way-progenitor galaxies at high redshift, resolving cold, clumpy outflows on 100 pc scales tied to star-forming clumps, and using multi-species diagnostics to map the density and chemistry of the cool Circumgalactic Medium (CGM). This requires a tenfold increase in spectral line sensitivity to push current observational limits.