A comparison of CO line profiles from GSS 30, as extracted on-source. Two Gaussian profiles are fit to the emission in coadded v = 2−1 lines. The same two Gaussian profiles are then compared with the coadded lines of ¹²CO v = 1−0 with high-J, with low-J, ¹³CO, and C¹⁸O. The two components in the v = 2−1 lines fit the other profiles reasonably well, although in the high-J line the broader component dominates. Some narrow extended emission can also be seen as excess emission in low-J¹²CO and ¹³CO lines at −5 km s^-1. Both of these Gaussian components are considered narrow, optically-thick absorption within our crude classification scheme.