  We examined the question of a possible correlation between 1.8 MeV emission
and intensity distributions observed at other wavelengths by comparing the 1.8
MeV data to an extended set of all-sky maps, covering the entire explored
wavelength range from the radio band up to high-energy gamma-rays. This
analysis revealed that tracers of the old stellar population or the local
interstellar medium provide only a poor description of the data. Tracers of the
young stellar population considerably improve the fit. Residuals are minimized
for the free-free emission map obtained by the DMR at microwave wavelengths and
the 158 um fine-structure line map of C+ observed by FIRAS. Within the
statistics of the present data, both maps provide an overall satisfactory fit.
We therefore conclude that adequate tracers of 26Al sources have now been
identified. Implications for 26Al source types are discussed (see also
Knodlseder, these proceedings).
