HIFI/WBS spectra of CO J = 16–15 (top), J = 10–9 (middle and bottom), and ¹³CO J = 10–9 (bottom). The spectra of low-J lines are overlaid in red (scaled for comparison) in the top and middle rows. For clarity, some spectra were rebinned to lower resolution: for CO J = 16–15 dv = 0.8 km s^-1 in HD 97048, HD 100546, and IRS 48, and dv = 0.32 km s^-1 in S CrA; for CO J = 10–9 dv = 0.52 km s^-1 in TW Hya and dv = 1.3 km s^-1 in HD 163296; for ¹³CO J = 10–9 dv = 0.56 km s^-1 in TW Hya and dv = 1.4 km s^-1 in HD 163296. The remaining spectra are shown at their native resolutions.