CO spectra obtained with our SMA observations. Orange and green histograms present the CO (2–1) and (3–2) emission, respectively. The spectra in both panel a and b were extracted by averaging over the region with a radius of 0.′′ 5 centered on the continuum peak position from the images with the correction of the primary beam attenuation. Dashed lines denote 1σ noise levels of the spectra. In panel b, the CO (3–2) spectrum was extracted after convolving the CO (3–2) image with the same angular resolution of the CO (2–1) image. Red and blue curves show the Gaussian fitting results of the line profiles.