Upper panel: Temperature asymmetry towards M 90 (in μK, with the standard errors) of V1 (A2+A3)–(A1+A4) in the four considered Planck bands at 70 GHz, 100 GHz, 143 GHz, and in the SMICA_H band. The temperature is measured within 0.5°, 1°, and 1.5°. Bottom panel: Same as the upper panel but for 360 control fields spaced by one degree from each other in Galactic latitude and at the same latitude as M 90.