Molecular spectra in the SW streamer region. (a) Integrated intensity ratio map of CO/¹³CO(1–0). The black contour is drawn at 15 and the blue contour at 21. The orange, purple, and yellow stars are the same as in Fig. 5c. (b) Averaged molecular spectra extracted from a beam-size region centered on the purple star in panel a. The color codes are labeled in the top left. The averaged intensity of the CO(1–0) line is scaled down by a factor of 100. The averaged intensities of ¹³CO(1–0) and HCN(1–0) lines are scaled down by a factor of 10.