Spectrum toward the MM1 peak. Top panel: lower side band. Bottom panel: upper side band. A common temperature range from −2 to 14 K is displayed for better visualization. Additional temperature ranges are shown for the upper (−2 to −20 K) and lower (14 to 42 K) sidebands to display the entire spectrum. A dashed lines marks the 0 K level. For both sidebands, the frequencies of the main molecular transitions are noted by a dotted vertical line and the transition is specified.