Mm. Shara et al., A deep survey for Galactic Wolf-Rayet stars. II. Implications for Galacticstructure and massive star formation, ASTRONOM J, 118(1), 1999, pp. 390-405
We have completed a direct narrowband-broadband Schmidt plate survey of lar
ge areas of the southern Milky Way for new Wolf-Rayet (W-R) stars as faint
as 19th b magnitude. The 31 newly detected stars in the completed survey ar
e among the reddest and/or most distant known in the Galaxy. We have obtain
ed spectra of all candidate W-R stars in the 22 fields stretching from l =
282 degrees to l = 341 degrees in longitude and Delta b = 3.degrees 5 in la
titude, covering about 180 square degrees. We also observed two isolated Mi
lky Way fields centered at l = 0 degrees and l = 8 degrees. Eighteen new W-
R stars are reported here for the first time. Combined with the 13 new W-R
stars we have already reported in Carina, our list of 31 new Galactic W-R s
tars reaches 3-4 mag fainter than previous surveys. Thirteen of our 18 new
W-R stars reported here are of subtype WN, while five are of subtype WC. We
present and describe their spectra and subtypes, derive their distances, a
nd discuss the significance of their locations along with all other W-R sta
rs in the Galaxy. Our new W-R stars clearly demonstrate an increasing numbe
r ratio of WN to WC stars with increasing Galactocentric distance. We concl
ude with predictions of the total number of Galactic W-R stars that should
be discovered in future IR surveys.