Emission and residual maps of the continuum emission and CH₃OCHO line emission at 217 GHz. a) The left and right panels, respectively, show the PdBI continuum emission map and residuals map. The residuals map was obtained by removing the two secondary sources as point sources, then removing the best-fit power-law model visibilities from the data visibilities, and imaging the residuals table. Contours show the levels of 3σ, 5σ, and 8σ, and then 10σ to 100σ in 10σ steps. The cross shows the phase center of our observations, coinciding with the peak of the continuum emission at 1.4 mm. b) The left and right panels, respectively, show the CH₃OCHO emission and residual maps. In the maps, the rms noise level is σ = 2.8 mJy/beam. Contours show the 3σ, 5σ, and 8σ, and then 10σ to 60σ in 10σ steps.