Uv-fitting of the four strong spectral lines detected in the inner CSE of W Aql. First row: RA offset position of the fitted Gaussian. Second row: DEC offset position. Third row: fitted flux-density of circular Gaussian for each velocity bin of 2 km s⁻¹. Fourth row: size of best-fitting circular Gaussian (FWHM). Fifth row: flux ratio of fitted delta function to Gaussian. For reference, the effective beam size in the observed images of 0.55″ × 0.48″ is indicated by a gray dashed line in the fourth row. The gray dashed lines in the two top rows denote the zero point of position offset in RA and DEC, respectively.