Example of a simulated source generated with a Spergel profile of S_tot/σ_b = 50, R_e/θ_b = 0.4, axis ratio of q = 0.75, PA = 30°, and Spergel index of v = −0.6. From left to right: the dirty image (top-left), dirty beam (PSF used for convolution in galfit; bottom-left), best-fit source models convolved with the dirty beam (middle), and residuals after subtracting the model source (right). The model source and the model-subtracted residual shown in the top and bottom rows were derived from the uv_fit and galfit fits, respectively. Each image cutout is 9″ × 9″. The contours start from 2σ and increase in steps of 4σ. White crosses mark the best-fit source position obtained from uv_fit.