Zoom in all detected and tentative lines. The rest frequency in MHz and the assigned molecule of each line are shown in the upper right of each panel. Weak lines have been smoothed to have a channel width of ~3.3 km s^-1, and they are marked with “smoothed” in the upper left of the corresponding panels. Otherwise, the channel width is ~0.8 km s^-1 (see Sect. 3.1). The blue dashed line traces the systemic LSR velocity (−26.0 km s^-1) of IRC +10216. In the C₆H 23 565.2 MHz panel, the other blue dashed line near −50 km s^-1 refers to the C₆H’s hfs component at 23567.2 MHz.