Total intensity spectrum of the ²⁸SiO v = 3, J = 5 − 4 (left) and the SO₂ (middle), and the ²⁹SiO v = 1, J = 5 − 4 (right) transitions around R Dor. The spectra are extracted using a circular aperture with a diameter of 0.09′′, 0.2′′, and 0.075′′ for the SiO v= 3, SO₂, and ²⁹SiO v = 1 lines, respectively. The observed spectra are shown in black. The best-fit CASA specfit model for each line is shown in red, while the residuals are indicated by the dashed blue histogram.