Radio image of the Andromeda Galaxy (M31) made at the 11-centimetre wavelength by the Effelsberg radio telescope near Bonn, Germany. The colour coding runs from red for the most intense radio emission, through yellow, green and blue, to purple for the least intense emission. The image shows a bright insringins - the galaxy's spiral arms - around the intense galactic centre. Most of the 11-cm radiation is synchrotron emission from fast- moving electrons spiralling around large-scale magnetic fields in the galaxy's arms and at its centre.