In the radio domain, the 408 MHz all-sky continuum survey  at a resolution of 0.85 degrees is a good tracer of the synchrotron emission. In particular, we use the 408 MHz all-sky map available on the LAMBDA website in the HEALPix pixelisation scheme .
Notice that we have not explicitly considered the canonical synchrotron emission in this model.
 who claim conclusive evidence for hard synchrotron emission. In our analysis, we did not dispose of data in the frequency range from 10 to 20 GHz to discriminate between this hypothesis and spinning dust emission (refer to  for a more complete review on spinning dust emission).
After subtraction of the thermal dust emission, we have shown that the microwave data can not be simply explained by a combination of free-free and canonical synchrotron emission. A more detailed analysis including AME has shown that the latter can be well approximated by a power law of average spectral index -2.5 in [K.sub.RJ] units.
The spectral index found for the anomalous emission is consistent with hard synchrotron emission [34,47].
The spatial angular power spectrum of the synchrotron emission [C.sup.sync.sub.l] is poorly understood but is believed to be [C.sup.sync.sub.l] [varies] [l.sup.-3] .
At higher latitudes, it must be separated from synchrotron emission by virtue of their different spectral indices, since the spectral index of optically thin free-free emission is [[beta].sup.ff] = 2.1.
Gutierrez, "Galactic synchrotron emission at high frequencies," Monthly Notices of the Royal Astronomical Society, vol.