7 September 2012

Mysterious haze seen by the Planck satellite

ESA's Planck mission (in which also Discovery scientists are invovled) has detected a mysterious haze from the region around the galactic center. The previous experiment, WMAP, has also detected a haze, but the Planck instruments are far superior to its predecessor's and has now mapped out the haze in great detail.

The new results are being presented this week at an international conference in Bologna, Italy, where astrophysicists from around the world are discussing the mission’s intermediate results.

The haze is seen in 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 curios thing 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 or possibly the annihilation of dark-matter particles. So far, none of them has been confirmed and it remains puzzling.

Read the whole press release from Planck here: Press release.