Top: Example ALSTAR fits for individual spaxels in three different regions of M101. Colored lines with error bars show the data (O_λ), while black lines show the model photometric fluxes (M_λ), and the gray lines show the corresponding high-resolution model spectrum. Images on the right show 278″ × 278″ composites built with the J0660, r, and g fluxes in the R, G, and B channels, respectively. Bottom: Distributions of the (O_λ − M_λ)/M_λ relative residuals of the fits for the 12 J-PLUS bands for 11 705 zones in M101. Median residuals are marked by solid black circles, while the horizontal bars mark the 16 and 84 percentiles.