  Radioactive 26Al is an excellent tracer for metal ejection in the Milky Way,
and can provide a direct constraint on the modelling of supernova feedback in
galaxy evolution. Gamma-ray observations of the 26Al decay line have found high
velocities and hence require a significant fraction of the Galactic 26Al in the
hot component. At the same time, meteoritic data combined with simulation
results suggest that a significant amount of 26Al makes its way into stars
before decay. We investigated the distribution into hot and cold channels with
a simulation of a Milky-Way-like galaxy with massive-star feedback in
superbubbles and with ejecta traced by 26Al. About 30-40 per cent of the ejecta
remain hot, with typical cooling times of the order Gyr. 26Al traces the
footpoints of a chimney-fed outflow that mixes metals turbulently into the halo
of the model galaxy on a scale of at least 50 kpc. The rest diffuses into cold
gas with temperatures less than about 10,000 K, and may therefore be quickly
available for star formation. We discuss the robustness of the result by
comparison to a simulation with a different global flow pattern. The branching
ratio into hot and cold components is comparable to that of longer term average
results from chemical evolution modelling of galaxies, clusters and the
intracluster medium.
