Observed transitions of CS and its isotopologues toward N113 overlaid with Gaussian fits indicated in green. The corresponding transition is indicated in the top-right corner of each panel. The blue dashed line indicates the systemic velocity of N113. The positions and relative intensities of the HFS components of C³³S (4–3) and C³³S (5–4) are indicated by the red vertical lines. In this plot, all spectra except CS (4–3) and CS (5–4) have been smoothed to a channel width of ∼1 km s⁻¹.