This can be read in the ESA site on news about the Planck probe: " Planck has also detected a mysterious haze of microwaves that presently defies explanation. It comes from the region surrounding the galactic centre and looks like a form of energy called synchrotron emission. This is produced when electrons pass through magnetic fields after having been accelerated by supernova explosions. The curiosity is that the synchrotron emission associated with the galactic haze exhibits different characteristics from the synchrotron emission seen elsewhere in the Milky Way. The galactic haze shows what astronomers call a ‘harder’ spectrum: its emission does not decline as rapidly with increasing energies. Several explanations have been proposed for this unusual behaviour, including higher supernova rates, galactic winds and even the annihilation of dark-matter particles. So far, none of them has been confirmed and it remains puzzling. " Could someone knowledgeable comment on this microwave haze, specifically why it is something so puzzling, and what its different synchrotron spectrum might mean? Thanks.