Top panels: decomposed surface brightness profile of NGC 628 along the major (left) and equivalent (right) axis. The data is represented as red circles while the model is the black curve. This galaxy has a central point source (green, dotted line), a Sérsic spheroid (red, dash-dotted line) and an exponential disc (blue, dashed line). Inset in the upper left are the best-fit spheroid parameters. Below the decomposition panels are the residual (Δμ) profiles.