NOEMA3D : Extended CO, [C I], and dust in massive star-forming main-sequence galaxies at cosmic noon

We present a spatially resolved study of cold molecular gas and dust in ten main-sequence galaxies at z=1.1-1.6, using observations of CO(4-3), CO(3-2), C i (1-0), and dust continuum from the survey. We find widespread spatially extended molecular gas and dust, with sizes comparable to those of the stellar disk, in contrast to those of centrally dominated starburst galaxies at similar redshifts. Among the targeted molecular gas tracers, the CO line (J=3-2 or J=4-3) remains the most effective for mapping molecular gas distribution and kinematics. The spatially resolved correlations between different molecular gas tracers exhibit about twice the scatter as their galactic-integrated correlations, indicating that interstellar medium (ISM) conditions already deviate from global averages on scales of 3-6 kpc. This likely reflects the clumpy or inhomogeneous ISM in cosmic noon star-forming galaxies. Within our sample, both the molecular gas fraction and its depletion time are nearly constant across the galactic disks out to 2 R_ , supporting a global linear Kennicutt-Schmidt law. These galaxies also have relatively small bulges, with bulge-to-total ratios between 6--24%, and are actively forming stars. These results provide a resolved view of how galaxies can remain on the star‑forming main sequence during their secular evolution at late cosmic noon, an evolutionary stage supported by quasi-steady gas accretion and efficient gas transport via prominent spiral arms and/or bars. e