Planck has observed the entire sky from 30 GHz to 857 GHz .
The observed foreground emission contains contributions from different phases of the interstellar medium ( ISM ) .
We have separated the observed Galactic emission into the different gaseous components ( atomic , molecular and ionised ) in each of a number of Galactocentric rings .
This technique provides the necessary information to study dust properties ( emissivity , temperature , etc .
) , as well as other emission mechanisms as a function of Galactic radius .
Templates are created for various Galactocentric radii using velocity information from atomic ( neutral hydrogen ) and molecular ( ^ { 12 } CO ) observations .
The ionised template is assumed to be traced by free-free emission as observed by WMAP , while 408 MHz emission is used to trace the synchrotron component .
Gas emission not traced by the above templates , namely “ dark gas ” , as evidenced using Planck data , is included as an additional template , the first time such a component has been used in this way .
These templates are then correlated with each of the Planck frequency bands , as well as with higher frequency data from IRAS and DIRBE along with radio data at 1.4 GHz .
The emission per column density of the gas templates allows us to create distinct spectral energy distributions ( SEDs ) per Galactocentric ring and in each of the gaseous tracers from 1.4 GHz to 25 THz ( 12 \thinspace \mu m ) .
The resulting SEDs allow us to explore the contribution of various emission mechanisms to the Planck signal .
Apart from the thermal dust and free-free emission , we have probed the Galaxy for anomalous ( e.g. , spinning ) dust as well as synchrotron emission .
We find the dust opacity in the solar neighbourhood , \tau / N _ { H } = 0.92 \pm 0.05 \times 10 ^ { -25 } { cm } ^ { 2 } at 250 \mu m , with no significant variation with Galactic radius , even though the dust temperature is seen to vary from over 25 K to under 14 K. Furthermore , we show that anomalous dust emission is present in the atomic , molecular and dark gas phases throughout the Galactic disk .
Anomalous emission is not clearly detected in the ionised phase , as free-free emission is seen to dominate .
The derived dust propeties associated with the dark gas phase are derived but do not allow us to reveal the nature of this phase .
For all environments , the anomalous emission is consistent with rotation from polycyclic aromatic hydrocarbons ( PAHs ) and , according to our simple model , accounts for ( 25 \pm 5 ) \% ( statistical ) of the total emission at 30 GHz .