Spectrum in the central beam toward the continuum peaks of IRAS 16293-2422 B. Predicted 30 _x, 30 − 29 _x, 29 transition lines of aG′Ag-12BD are overplotted as red sticks. The X-axis represents the frequencies in the rest frame of the system (i.e., corrected for the system V _LSR of 2.7 km s⁻¹; Jørgensen et al. 2011). The green line is an indication of the rms level (1.89 mJy beam⁻¹) represented by a spectrum extracted from an off source position.