ALMA contours on HST images for MS galaxies. For each galaxy, the left column shows the rest-frame UV from ACS F606W and F814W (equivalent to 2020 and 2710 Å rest-frame at z ~ 2), whereas the right column includes the HST–WFC3 F160W band (1.6 μm) sampling therest-frame 5300 Å band at z ~ 2 (here RGB = V, I, H). The ALMA contours correspond to 1.3 mm for the UDF sources and 870 μm for the GS source. Contours: for the UDF galaxies increase with steps of 0.5σ starting from 2.2σ, for the GS galaxies: 3σ steps up to 14σ, then 21, 29, 36σ. The dashed crosses are centered on the WFC3 F160W band center. The ALMA PSF is shown in the bottom left of each figure.