¹²CO (left) and ¹³CO (right) emission of the five gas-bearing disks in ARKS, HD 9672, HD 32297, HD 121617, HD 131488, and HD 131835 (from top to bottom). The first and fourth column in each row shows the spectrally integrated-intensity map of each disc for ¹²CO and ¹³CO, respectively. The minimum line intensity of these integrated-intensity maps was set at 0 mJy km s⁻¹ beam⁻¹. The second and fifth columns shows the peak velocity map of each disc for ¹²CO and ¹³CO, respectively. Each is centred on the stellar velocity of the systems, and any pixel outside of the velocity range shown in the colour bar is set to black. The peak-intensity (brightness temperature) map of each disc is shown in the third and sixth column for ¹²CO and ¹³CO, respectively. The minimum brightness temperature shown in the colour bar is the mean of the emission far from the discs. The ellipse in the lower left corners of the maps is the synthesized beam of the observations. The white scale bar in the bottom right corners indicates 50 au.