Distribution of the non-thermal emission from M 101 at λ 6.2 cm (contours) superimposed onto the non-thermal degree of polarization (greyscale). Contour levels are 1, 2, 4, 6, 8, and 12  mJy/beam area . The centre position is indicated with a plus. The maximum in the emission NE of the centre is due to the background source number 20 in the list of Israel et al. (1975). The noise level in the non-thermal intensity is about 0.5 mJy/beam area . In the centre region, strong depolarization causes very low non-thermal polarization degrees. The beamwidth is .