The galactic distribution of Wolf-Rayet stars

The galactic distribution of 132 of the 159 known galactic Wolf-Rayet (WR) stars is determined on the basis of the most recent compilation of narrow-band photometry and absolute visual magnitudes of WR stars, and by adopting a normal interstellar extinction law in all directions. Results show that the spiral structure is more clearly pronounced than in earlier studies, and an indication is found of two spiral arms at r = 4 and 6 kpc. An asymmetry of the z-distribution of single stars with respect to the galactic longitude is also found. In addition, the location of the WC 8.5 and WC 9 stars between 4.5 and 9 kpc from the galactic center is examined in the context of Maeder's red supergiant to WR star scenario.