Upper panel: temperature asymmetry toward M 81 in μK (with the standard errors) of the A1+A2 region (indicated as A12) with respect to the A3+A4 region (A34) in the five considered Planck bands (see text for details) within three radial distances of 30′ (R0.50), 60′ (R1.00), and 90′ (R1.50). Bottom panel: same for the 360 control fields with the same geometry (shown in Fig. 1) equally spaced at one degree distance from each other in Galactic longitude and at the same latitude as M 81.