NGC 3448. The first row shows from left to right the 144-MHz maps at 6 and 20 arcsec resolution, respectively, and the radio spectral index map between 144 and 6000 MHz at 20 arcsec resolution. Contours start at 3σ with increments of a power of two. The black circle shows the optical D₂₅ diameter and the blue ellipses show the 3σ contour extent used to integrate the flux density. The second row shows again the 6- and 20-arcsec images without contours and the radio spectral index error. The third row shows the 6- and 20-arcsec contours overlayed on an rgb SDSS image as well as contours of the radio spectral index. The filled circle shows the synthesised beam. A scale bar shows the projected size at the distance of the galaxy.