Planck view of the M 82 galaxy

Planck data towards the galaxy M 82 are analyzed in the 70, 100 and 143 GHz bands. A substantial north-south and east-west temperature asymmetry is found, extending up to 1 from the galactic center. Being almost frequency-independent, these temperature asymmetries are indicative of a Doppler-induced e ect regarding the line-of-sight dynamics on the halo scale, the ejections from the galactic center and, possibly, even the tidal interaction with M 81 galaxy. The temperature asymmetry thus acts as a model-independent tool to reveal the bulk dynamics in nearby edge-on spiral galaxies, like the Sunyaev-Zeldovich e ect for clusters of galaxies.