Spectra of the full frequency range surveyed by the ALMA observations, toward the six cores identified in the continuum image (see Fig. 1). The spectra are extracted by averaging the intensity over an area of 1.37, 2.35, 1.04, 0.55, 0.75, 0.44 arcsec², yielding conversion factors of 8.9, 5.0, 11.3, 21.7, 15.7, 27.1 K Jy^-1, for cores A to F respectively. The brightness temperature scale of cores A and B is different from that of the rest of the cores. The absorption seen in some spectra is likely produced by the filtering of extended emission.