Left: positions observed in the area surrounding CN 38. Green circles at the on-position indicate the beam sizes at 230 GHz and 345 GHz. Shell positions are indicated in red and off-positions are shown in white. Image size is ~45″ × 120′′. The yellow bar shows the orientation of the east-west direction (east left). Right panels: the corresponding Hanning-smoothed shell spectra (top) and the on-position spectra of CN 38 (below); green: ¹²CO(2–1), black: ¹²CO(3–2), and blue: ¹³CO(2–1).