Various ¹²CO transitions for Mrk 996, NGC 3353, NGC 7077, NGC 1156, and UM 448. Top row: ¹²CO(1–0), ¹²CO(2–1) (IRAM), and ¹²CO(2–1) (APEX) for Mrk 996; second row: ¹²CO(1–0) for NGC 3353 (Haro 3) for three pointings ([0, 0], [0, +10′′], [−6′′, −9′′]); third row: ¹²CO(2–1) for NGC 3353 (Haro 3) for three pointings; fourth row: ¹²CO(1–0), ¹²CO(2–1) (IRAM), and ¹²CO(3–2) (APEX) for NGC 7077 (Mrk 900); fifth row: ¹²CO(1–0) for NGC 1156 and UM 448, and ¹²CO(2–1) (APEX) for UM 448; bottom row: ¹²CO(2–1) (IRAM) for NGC 1156 and UM 448 and ¹²CO(3–2) (APEX) for UM 448. The baselines are shown as a horizontal solid line, together with the multiple-component Gaussian fits as described in Sect. 3.3. The vertical axes are in units, while in Tables 2 and 3 the units are T_mb, converted from as described in Sect. 3.3. Velocity channels are as reported in Table 2. The red curves and lines refer to 30-m spectra, while the blue ones to APEX.