Non-thermal intensity of M 31 at λ3.6 cm with $1\stackrel{\prime }{.}5$ resolution (corrected for AME) (top), at λ20.5 cm with $1\stackrel{\prime }{.}5$ resolution (middle), and at λ3.6 cm with $2\stackrel{\prime }{.}5$ resolution (corrected for AME) (bottom). The rms noise is ≃0.25 mJy/beam (top), ≃0.25 mJy/beam (middle), and ≃0.4 mJy/beam (bottom). Contour levels are at 0.75, 1.5, 2.25, 3.0, and 4.5 mJy/beam (top), 2.5, 5.0, 7.5, 10, 15, 20 mJy/beam (middle), and 1.25, 2.5, 3.75, and 7.5 mJy/beam (bottom). The half-power beam widths are indicated in the bottom left corner. Bright background sources and the unresolved central source of M 31 have been subtracted. At λ3.6 cm, large-scale emission is missing in the central region.