Finding Wolf-Rayet Stars in the Milky Way: Inputs to Star Formation and
  Stellar Evolution
  The total population of Wolf-Rayet (WR) stars in the Galaxy is predicted by
models to be as many as $\sim$6000 stars, and yet the number of catalogued WR
stars as a result of optical surveys was far lower than this ($\sim$200) at the
turn of this century. When beginning our WR searches using infrared techniques
it was not clear whether WR number predictions were too optimistic or whether
there was more hidden behind interstellar and circumstellar extinction. During
the last decade we pioneered a technique of exploiting the near- and
mid-infrared continuum colours for individual point sources provided by
large-format surveys of the Galaxy, including 2MASS and Spitzer/GLIMPSE, to
pierce through the dust and reveal newly discovered WR stars throughout the
Galactic Plane. The key item to the colour discrimination is via the
characteristic infrared spectral index produced by the strong winds of the WR
stars, combined with dust extinction, which place WR stars in a relatively
depopulated area of infrared colour-colour diagrams. The use of the
Spitzer/GLIMPSE 8$\mu$m and, more recently, WISE 22$\mu$m fluxes together with
cross-referencing with X-ray measurements in selected Galactic regions have
enabled improved candidate lists that increased our confirmation success rate,
achieved via follow-up infrared and optical spectroscopy. To date a total of
102 new WR stars have been found with many more candidates still available for
follow-up. This constitutes an addition of $\sim$16\% to the current inventory
of 642 Galactic WR stars. In this talk we review our methods and provide some
new results and a preliminary review of their stellar and interstellar medium
environments. We provide a roadmap for the future of this search, including
statistical modeling, and what we can add to star formation and high mass star
evolution studies.
