Radioactive and kinematic tracers of feedback from massive stars
  The mixing of ejecta from young stars into the interstellar medium is an
important process in the interplay between star formation and galaxy evolution.
A unique window into these processes is provided by the radioactive isotopes
$^{26}$Al, traced by its $\gamma$-ray decay lines at 1.8 MeV. With a mean
lifetime of $\sim$1 Myr it is a long-term tracer of nucleosynthesis for massive
stars. Our population synthesis code models the ejection of $^{26}$Al, together
with the $^{60}$Fe, the kinetic energy and UV radiation for a population of
massive stars. We have applied the code to study the nearby Orion region and
the more massive Carina region and found good agreement with observational
constraints.
