The galactic distribution and subtype evolution of Wolf-Rayet stars. III.

Using new classifications for 46 WR stars and new photometry for 78 WR stars, the Galactic WR intrinsic parameters are redetermined, revising the WR Galactic distribution. For stars with heliocentric distances less than 2.5 kpc, it is found that the WN/WC number ratio is 0.55, indicating a larger influence of mass loss and overshooting than accounted for in present evolutionary models. By comparison with a theoretical mass-luminosity relation an average bolometric correction of -4.2 + or - 1.2 is found for WR stars in binaries located in open clusters or associations. A mathematical comparison with the distribution of O-type stars is used to find the initial masses of progenitors of WR, WN, and WC stars. It is suggested that WNL stars with galactocentric distances beyond about 6.5 kpc evolve into WCE stars, whereas WNL stars within galactocentric distances of about 8.5 kpc evolve into WCL stars.